Photosynthesis Overview

Hi! Welcome to another lecture video. So for today's video, we're going to talk about something very important in our biological system, not only in our environment but in the whole history of life and in the whole biosystem of the world. So before we start our session or our lecture video rather, I'd like to ask this particular question. What distinguishes plants from other organisms right now you're thinking of a particular answer maybe you're thinking of plants are colored green plants cannot move plants are are or can make plants can make their own food rather all right so these are some of some of the things that might arise in your um in your reflection? Well, most of them, or if not all, are correct. One of the very important characteristics of life that we can get from this question is that plants have this characteristic to make their own food in the process of photosynthesis. And that will be our topic for today's lecture video. So welcome to another lecture video all about photosynthesis. The title of my lecture video is Life Starts with Photosynthesis. So let's get started. This will be our target competencies for the whole topic on photosynthesis. So this lecture video is not only composed of one thing. one video but a series of videos discussing and completing the following competencies. Number one, we have to explain the importance of chlorophyll and other pigments. Then, describe the patterns of electron flow through the light reaction events and describe the significant events of the Calvin cycle. You might wonder what are these terms that somehow are new to me. the light reaction and the calvin cycle we'll take a note that of that when we go to the other lecture videos to be posted in our lecture in our google classroom now to be more specific for our lecture video this will be our learning objectives so number one we have to define photosynthesis through its chemical equation. We know that photosynthesis is... a process and is a chemical reaction between different compounds now as a bio student or as a stem student we have to take a look at this process in detail all right then when we go to another topic called um the cellular respiration we will be checking um And we will be checking its chemical equation and we will try to connect it with the chemical equations of photosynthesis. Second, we have to label the different parts of the plant that performs photosynthesis such as the leaves and the chloroplasts. So particularly the leaves and specifically the chloroplasts. So we have to go back to our basic science and even in our GenBio 1 session. the the parts of a plant cell third we have to explain the role and importance of pigments water light and carbon dioxide in photosynthesis so pigments are are not part of the chemical equation but they play a very significant role in the whole process of photosynthesis water light and carbon dioxide made it possible for photosynthesis to occur. Then finally, evaluate the importance of photosynthesis to life on earth. Yes, why does photosynthesis need to be in the world? Or is photosynthesis really that important? Perhaps you already have an idea based on the title of our presentation for this lecture video. So let's get started. Now I want you to take a look at this photo. Okay, what can you see? May nakikita tayong animals. What animals can we see? so we can see different mammals such as an antelope an elephant zebra okay and i want you to take a look at what do these animals do in their environment what are they doing in their environment they are eating all right now let's take a look at another photo okay so from from the land going to the deep waters. What can you see? You can see different corals, different corals of different color and different marine organisms such as different species of fish and other invertebrates as well. Now, why do these organisms gather in a particular area. Perhaps because they have a habitat there, they have a food to eat. Okay. Now, in both areas, we can see that plants are very important part of the ecosystem. Okay. Both the aquatic and the terrestrial environments, ecosystems, are feeding on plants. You might not see carnivorous animals or organisms eat plants, but if you remove those organisms that feed on plants, for sure, they will also be erased. I wanted to take a look at this particular illustration. This is a food web of Now this is a food web showing how animals feed on other organisms. At the base of this illustration, we can see that plants are present. Try to imagine when we remove plants in this food web. What could happen in this food web? Alright, so tama yung naiisip natin. The food web will eventually collapse. Okay, meaning... If we remove the plants in the food web, the animals that feed on plants will die because of starvation. And this will cause a domino effect to those organisms that do not feed on plants but rely their food from other organisms. Those that we call the carnivorous organisms. Pero sir, noy. There are no or little plants found in the aquatic environment. That's right. Okay. We only have limited plants in the aquatic environment. Now, is this also true in the aquatic environment? Yes. Alright. There might not be, there might be no plants, okay, in the sea. But there are also organisms that act as a plant, okay? And these plant-like organisms feed or are being eaten by smaller organisms in the sea. Okay? Like, say, for example, the phytoplanktons, such as the diatoms and the dinoflagellates, They are the source of food of small fishes such as the fish larvae and small fish like the anchovy or dillis. And bigger fish and microorganisms in the sea will feed on these smaller organisms. We do not see sharks feeding on plants. But we see sharks are fish-eating organisms. Okay? And these fish-eating organisms feed on fish that are plankton-eating organisms. Okay? So, ibig sabihin, okay, in both aquatic and terrestrial ecosystems, may mga nasa base ng food web. If we remove them from the food web, the ecosystem will keep on falling. Now, diatoms, itong mga phytoplanktons found in the seas are not plants. But they act as a plant. Bakit kaya? Bakit kaya sila tinatawag na plant-like organisms? If you think that because they also make their own food, then you are. Correct. Okay. Because for today, we are going to talk about photosynthesis. This is a simple illustration of how plants benefit us. Okay. So plants take up the carbon dioxide that are being exhaled by animals and they transform it to oxygen which we breathe in and which we need inside our body. Not only humans need oxygen but also other organisms, particularly animals. So photosynthesis is an essential process in our ecosystem. that if we remove photosynthesis from the equation, of our ecosystem, everything will fall down. Alright? It's as if that if we remove photosynthesis, we also remove plants in the equation. So, if we are asked, what is the importance of photosynthesis in life? Okay. So, why? What is the importance of photosynthesis in our lives? And that is, photosynthesis is equal to life on Earth. Just imagine a life or a world without plants do photosynthesizing. Where can we get food? Sir Noy, the pigs that are bought in the market. Okay, that's right. But let's think, where do the pigs get food? yung mga baka, yung isda na kinakain natin, everything will boil down to plants. So without the plants on Earth, the diversity of organism will not be possible. Again, may buhay pa naman sa mundo kung kahit walang plants. Pero hindi siya magiging diverse, mausbong. And because it's beautiful like what we have now. Because only microorganisms can thrive without plants and without photosynthesis. Let's continue. Now, photosynthesis literally means putting together with light. Photosynthesis came from the two words photo meaning light and synthesis meaning putting together. So when plants do photosynthesis, they are putting together the raw materials needed for these processes. And what are these two materials? We have carbon dioxide and water. So with the use of light, water and carbon dioxide are being put together, not literally but in a in a long important process in order to make In order for plants to make food of their own and at the same time release oxygen for us to breathe in. Okay? So, photosynthesis is an autotropic process. Meaning, in this process, plants are able to make their own food. Plants, and not only plants, but plant-like organisms such as the phytoplankton. make energy in the form of glucose from sunlight. Let us all recall our discussion on biomolecules. Glucose is an example of what particular biomolecule? That's right. So that is an example of a carbohydrate. And carbohydrates functions as an energy source for different organisms. So this is where what we learned in biomolecules that carbohydrates gives energy to different organisms. So plants use sunlight to turn water and carbon dioxide into glucose. Now, this glucose are stored as carbohydrates in their bodies. So that's why plants are a good source of carbohydrates. For example, the fruits that we eat, the sweetness of the fruit that we eat is the carbohydrates stored by the plant inside their bodies. Okay? Say, for example, another example are vegetables. Yung patatas na kinakain natin. Okay? So, pag kumakain tayo ng fries, sabi natin, kumakain tayo ng carbohydrates. So, yung fries, galing yun sa halaman ng patatas. Okay? So, the... the glucose the carbohydrates stored by the potato plant inside their body are the fries that we buy and we enjoy okay now photosynthesis occurs in plants particularly in the chloroplane in the chloroplast inside the cells of the leaves so if you're asked what do you call the parts of the plant that performs photosynthesis Ang sagot natin ay leaves. So, yung leaves ay photosynthesis machinery of the plant. Okay? Now, inside the plant cells, sa bawat cells ng dahon, mayroong chloroplast para mag-photosynthesize. Okay? To be more specific, this is where photosynthesis occurs. Inside the chloroplast. So this is the chemical formula or the chemical equation for photosynthesis. We have 6 carbon dioxide plus 6 water plus sunlight will give us C6H12O6 or glucose plus 6 molecules of oxygen. Let us recall our understanding on chemistry. It says here, may anim na carbon dioxide, okay, plus may anim na water molecules, plus sunlight, okay, kailangan natin ng anim na carbon dioxide, anim na water molecules, at sunlight, para makapag-produce tayo ng isang molecule ng glucose at anim na molecules ng oxygen, okay? just think of it just think of this as a cookbook okay so we need this kind of ingredients so that we can produce plants with glucose and oxygen so you can see here a more creative version of the chemical equation of photosynthesis so again Plants need six molecules of carbon dioxide, six molecules of water, plus sunlight in order to produce one molecule of sugar in the form of glucose plus six molecules of oxygen. Now, the sunlight that is present in the chemical equation for photosynthesis is. is actually absorbed by one important molecule inside the plant and these are what we call the chlorophyll. Later on, we'll be talking about what is a chlorophyll and what is its function in the plants. And how do we know that a plant has a chlorophyll? So why is photosynthesis important in... in our ecosystem and not only for the plants. So as you can see on the left side of the screen, a hydrilla plant that is photosynthesizing. So why did we say that this plant is photosynthesizing? Okay, I want you to observe. We don't see the process itself, but there is one important indicator on why. nasabi natin na nagpo-photosynthesize siya. Alright? It's because of the bubbles. So, why is photosynthesis important? in plants. So number one, because photosynthesis makes organic molecules out of inorganic materials such as carbon dioxide and water. So these organic molecules is a carbohydrate that is badly needed by plants in order to function. And in terms of energy transformation, This glucose or carbohydrates, this is what we get from plants. so that our body systems and cells can function. Second, it begins all food chain and food web. As I said, without plants, there will be no food for our herbivores and other animals that rely on plants, including humans. Then also, One important indicator of photosynthesis is the gas molecule, which is found in this image. The bubbles that we see there, these are oxygen gases produced by the plant after photosynthesizing. Let me emphasize that plants produce oxygen because oxygen is a byproduct of photosynthesis. What I mean by byproduct is waste material sya ng photosynthesis. O diba, napakasyala. Okay, waste product ng plants, yung oxygen na needed natin. At the same time, tayong mga animals, okay, ano yung waste product natin? Na gas. Okay, hindi utot, pero These are carbon dioxide. Okay, yung carbon dioxide na badly needed ng plants para mag photosynthesize, waste material lang natin yun. Alright? So, yun. So, photosynthesis starts to ecological food web. So, the sun is the source of energy for most living things. Now, plants such as grass use this energy from the sun to make their own food. then An herbivore such as the zebra obtains energy by eating the grass. Then, later on, the lion obtains energy by feeding on the zebra. So, ibig sabihin, okay, para siyang gears na kapag hindi gumana yung isang gear, hindi na iikot yung ibang gears. Okay? We are all connected. Okay? Ecologically speaking. So kapag walang araw, If there's no light, plants will not photosynthesize. Zebra will not eat either. Lions will not eat either. If one of these does not work, it will have effects on the next processes. So let's try to review. So what is the process that makes the sun's energy to make simple sugars? This is photosynthesis. And what do we call these simple sugars? This is glucose. What are the molecules that absorb energy from the sun? It's not water. It's not also carbon dioxide. These are chlorophyll. And what is the general formula of photosynthesis? We need the complete general formula. That is 6 CO2 or carbon dioxide plus 6 H2O or water plus sunlight will give us C6H12O6 or glucose plus oxygen. 6 oxygen molecules. So let's try to understand the leaves. So the leaves are the main organs for photosynthesis. Thus they are called as besides for food synthesis because technically they are food factories of the plants. This is where the plants photosynthesize. Thus this is their main organ where they make their own food particularly the glucose. But Let it be known that it is not always the leaves that do the photosynthesis. green parts of the plants are areas for photosynthesis also. So, we can see that parts of the plant that are color green, they are also suspected parts of the plant that do photosynthesis. So, sometimes, there are plants that have no leaves, but they still continue to thrive because it's not only the leaves that do photosynthesis. Alright? So, that's it. Even the stems, the roots, and even flowers and fruits can do photosynthesis. Now, why are leaves color green? It's because they contain chloroplasts, which contains chlorophyll, which are sites for photosynthesis also. The main organelle, if the leaves is the organ for photosynthesis, The chloroplasts are the organelles for photosynthesis. That means deep within the plant are chloroplasts that functions for this particular process. So as you can see, these are different species of plants that we can see. So we have here catmone. So if we can see, Catmon's color is green. dahon. So again, why are they green? Because they are areas for photosynthesis. Same goes with bitaog. The fruits of bitaog are colored green. So nagpo-photosynthesize din itong prutas na to. We also have an orchid at the lower left side of the screen where the roots are also colored green, meaning they are filled with a lot of chloroplasts. and chlorophyll that functions in the absorption of light so that they can photosynthesize. Now let's take a look at the different parts of the leaves. What are the different parts of the leaves? So first, we have the cuticle. So the cuticle is a waxy layer that protects the leaves from excessive loss of water. The leaves are exposed to the sunlight. or in many cases they are directly exposed to the sunlight. Thus, in order to prevent dehydration, many many leaves had evolved and had cuticles on the upper side of the leaves. So also, below the cuticle, we have that. epidermis. So the epidermis covers the leaves which also gives protection to the leaves. So the epidermis is not only found on the upper side of the plant but also at the lower side of the plant. It's like we're just covering it. If you put our arm horizontally, the ones exposed in the sun is is the epidermis. While the part of our skin that is not exposed to the sun is still called as the epidermis. So their main function is to protect the leaves and also prevent it from losing excessive water. Remember that plants need water in order to live. So since they are exposed to the sunlight, they have this particular adaptation. So as you can see, we have a Hoya species and a Calathea species on your screen. If we're going to take a look at these two plants, we'll think that the leaves of these two plants are like plastic. Because there is a very waxy layer. and on on the upper side of the of their leaves now the waxy or the shiny part of the leaves is shiny because they are covered with cuticle so at the middle layer of the leaf is the mesophyll from the word meso meaning middle so this is the inner layer of the leaves which functions for the actual photosynthesis dito na yung pinaka photosynthesis nangyayari. And it has a lot of chloroplasts. On the lower, on the underneath, the leaves, at the back of the leaves, these have stomata. So the stomata allows gas to enter and leave from and to the leaves. So here, gases come out and enter. So what are the gases that come out and enter? We have carbon dioxide and water. Because remember that carbon dioxide has to enter the leaf in order for photosynthesis to occur. Under the microscope, if we look at the leaf, under the microscope, there is something that opens and closes. These are the stomata. So here, this is an illustration of an open stomata. And on the other hand, this is a micrograph of a stomata. So nasaan dito yung stomata? Yan pong mga bilog-bilog. If we will be having another micrograph of the stomata, eto yun. Para siyang mga mata. Kaya isipin na lang natin stomata, mata. Nagbubukas, nagsasara. Pero anong function ng stomata? Hindi siya tulad ng mata natin para makakita. Yung stomata ng mga halaman, They open and close in order for gas exchange to happen. Carbon dioxide will enter here and carbon dioxide will also come out here. Then, let's talk about the mesophyll. The mesophyll, this is still divided into two layers. The first one is what we call the palisade mesophyll, which contains a lot of chloroplasts. And they are adapted. for the absorption of light efficiently. So remember, at this part of the plant where there's a cuticle, this is where the sun is the most active. Okay? So after the cuticle, there's an epidermis. Okay? And below the epidermis is the palisade mesophyll. Okay? If we can see the palisade mesophyll, In comparison with the spongy mesophyll, they have different structure of the cells. So why do they look like this? Because this is where the sunlight is. So when the sunlight hits here, it directly absorbs the chloroplasts. and the spongy meso feel okay They are located below, near the stomata because they aid in the gas exchange of photosynthesis. The stomata is also below because the stomata cannot escape from the area where they are sunbathing. Because if the stomata escapes, they will be prone to loss of water. That is why adaptation of plants is important. Sa ilalim nagkakaroon ng gas exchange. Then, one observable part of the plant are the vascular bundles, the veins of the plant. So there are two types of veins which functions for the transportation of materials inside the plant. So we have the phluem. And we also have the xylem. So, fluem is a particular vascular vein in the plant that functions for the distribution of organic materials. Okay? The glucose that Chloroplasts produce after photosynthesis is transported by fluem. Okay, para lang. factory. When the product is made, there are delivery channels to pass through the products and it will go to different areas. For example, when glucose is produced, the fluem, I mean the glucose will go to the fluem and the fluem will distribute to different parts of the plant. If you want, um... transports organic materials or the food, xylem transports and distributes water. So from the roots, how does the water that was absorbed by the roots reach the plants? It's because of the xylem. So so that we won't get confused, fluem transports food, Tandaan natin, food sounds like F, fluem, yung first syllable sounds like letter F. Fluem, food. On the other hand, xylem, um, xylem, this remutes water. What's the letter before letter X? It's W. Okay, xylem starts with letter X, and the letter before X is W, so water. Okay? So these are the different parts of the leaves. Okay, let's try to review so we won't forget. So the first part is the cuticle. So the cuticle is again a waxy layer that protects the plants from excessive heat in order for the plant not to lose a lot of water. Okay, this is usually the part that is very exposed to the sun. So to avoid the... loss of water, the plants adapted to their environment and produced cuticles. Then we also have the upper epidermis, the ones that is just below the cuticle. The middle layer that we call the mesophyll. The lower epidermis, the stomata, which is part of the lower epidermis the stomata functions for the opening and closing of the leaves and for gas exchange the palisade mesophyll and the spongy mesophyll so let's see what's the difference between the two okay i wanted to take a look at the structure of palisade mesophyll and spongy mesophyll So that we can easily identify the two main divisions of the mesophyll. We also have the vascular bundles which comprises the xylem which transports food and phluem which transports the food materials or we can also call that as the organic materials or carbohydrates. Let's become more specific by taking a look at the different parts of the chloroplast. So again, one of the major differences of animal cell from plant cell is the presence of chloroplast. Because it's only the plants and plant-like organisms that can photosynthesize. No animal can photosynthesize so far. Okay, then. chloroplast contains chlorophyll which is a pigment that absorbs all light except for green so that's why we see green because the chlorophyll absorbs all color but reflects the color green so the reason why um the reason why um plants are generally green because yung chloroplast, meron silang chlorophyll na inaabsorb niya lahat ng chloroplast. kulay ng ilaw except for color green. That green called the green light is being reflected back to its environment. So the encircled organs are the chloroplasts. So these are the parts of the chloroplast when we take a look at it in detail. So it has an inner membrane, the outer membrane is the chloroplast. We also have the thylakoid, the lamellae, the stroma. The stroma is the fluid inside the chloroplast. The granum as well. So what is the difference between the granum and the thylakoid? The thylakoid is the individual that is round. And when the thylakoids are stuck, we call them granum. The plural of granum is grana. So, just imagine the thylakoids as pancakes. A single pancake is called thylakoids. When we cut the pancakes into pieces, we call them granum. Okay, pag maraming stacks ng pancakes, grana na ang tawag natin. and we also have the lumen. The lumen is the innermost part of the thylakoid. So the thylakoid contains the photosynthetic pigments. So what are these photosynthetic pigments? We have the chlorophyll. Remember that photosynthetic pigments are Um, are the light absorbing molecules found in plants. And these plants mostly contain the chlorophyll, which is a particular example of a photosynthetic pigment. So the granum or the grana are stocks of thylakoids. The stroma is a fluid structure found in the thylakoid okay and the lamellae connects the granum together okay um let's continue now um wild type plants have 80 to 100 chloroplasts per mesophyll cell so just imagine how many i know how many chloroplasts are there in one single leaf sa isang sel pa lang ng dahon, meron na siyang ano, 80 to 100 chloroplasts, what more than one leaf? So, the number of chloroplasts is now millions. Now, under the light microscope, the chloroplasts are the ones we see in the green circles. Okay, on the other hand, under the light microscope, a chloroplast looks like this one. So leaves are green because they contain the pigment chlorophyll. So they are the reason why plants are green. Now leaves have a large surface area to absorb as much light as possible. So this is the reason why leaves are flat. Why they are not spherical or cubic in shape or pyramid in shape of leaves? is because So that they have more light to absorb, they are flat. Okay, so that they have much surface area. Then, chloroplasts are solar-powered chemical factories. Their thylakoids transform light into chemical energies of ATP and NADPH. So, that's it. The ATP is formed by the thylakoids. and we know that ATP is our energy currency. This is the energy of the plant. So light is a form of an electromagnet energy that is also called as an electromagnet radiation. So we have a physics concept here that light is an energy. It's a form of energy. Now We have to discuss light because we have to give a reason kung bakit color green ang plants. Now, visible light contains wavelengths that produce color. If meron tayong prism, kapag tinamaan niyo ng ilaw, it will give us different colors of light. Okay? Hindi lang puti ang ilaw. visible light but it is composed of different colors. Now light behaves as though it contains discrete particles called photons. So we believe that light is composed of particles that we call photons. Now pigments are substances that absorb these visible lights. Now different pigments absorb different wavelengths. And wavelengths that are not absorbed are reflected or transmitted. Some examples of pigments are chlorophyll, anthocyanin, and carotinine. So yung pinaka common sa plants is the chlorophyll. Si chlorophyll, they appear green because they reflect and transmit green light. Inaabsorb ni chlorophyll lahat ng kulay ng ilaw except for color green. Remember, sa prism, In the prism, the light that our eyes see, we think it's just white. But in reality, it's different colors. It's a ROYGBIM. The plant absorbs the red, orange, yellow, blue, indigo, and violet. But it doesn't absorb the green. Instead of absorbing it, it reflects it. Okay? There are some plants also that are not color green. Like say for example, this particular leaf. This particular leaf is color green because dominantly, it has anthocyanins. Anthocyanins absorb, it's a kind of pigment that absorbs all colors except for red. So, It has a red color. Carotinins, carotin, sorry, carotins, absorbs all color except for yellow or orange. Kaya may iba't-ibang kulay ng dahon tayo. Okay? Hindi lang green, pero most plants are green color. The rest are other colors. Ayan. So, this is a very good example of what i am saying earlier so see light coming from the sun okay will be will be absorbed by the will be absorbed by the chloroplast tapos my chlorophyll and my thylakoids so you can even cool in an an email you absorb your except for color green see color green It reflects or transmits. If we notice, later on, the light is not of any other color except for color green. That's why we see the plant as color green. Because again, chlorophyll absorbs all colors except for color green. There. So this is a graph showing the different pigments of plants. So we can see here that they absorb a particular color. Like say for example, I want you to focus on chlorophyll A and chlorophyll B. We can see here that their absorption is high when it comes to blue color. But when it comes to green color, their absorption is very low. They don't really absorb the green color. But they absorb other colors more except for green. Okay? When it comes to orange and red, they absorb it again. Okay? Let's take a look at this carotenoids. So carotenoids is another pigment. It absorbs all colors except for The colors are orange, yellow, until red. You're reflecting this color. That's why it looks orange. This is also the same example earlier. Plants produce several different light-absorbing pigments. Each photosynthetic pigment absorbs and reflects specific wavelengths. Again, let's go back to chlorophyll. When it comes to chlorophyll, it absorbs the colors of purple, blue, but as the graph shows, it decreases when it goes to green. Then it increases again when it goes to yellow, orange, and until red. So technically, we can see here that chlorophyll is not absorbed by the green color. Instead of absorbing the green color, this is reflected. Okay? That's why we can see color green. So Sir Noy, why in other countries, when there's a fall, or fall season na, bakit nag-iiba yung kulay ng halaman? Very good question. So, yun. Generally, nag-iiba yung kulay ng mga halaman ng leaves, particularly during fall, kasi during fall season, brine-breakdown ng halaman yung chlorophyll. So, walang chlorophyll or na uubos yung chlorophyll ng mga ng mga halaman pagdating ng fall. Since wala masyadong chlorophyll ang halaman, lumilitaw yung ibang pigments sa loob ng halaman such as the carotenoids and other pigments. So as we can see, in the fall season, chlorophyll A and B molecules are broken down and stored in branches. So they are being broken down, wala sila sa dahon, so lumilitaw yung ibang pigment. such as the carotenoids. Okay? Pag spring season, okay, yung mga chlorophyll, nando doon sila sa mga halaman. Kaya sila, mataas ang level ng chlorophyll. Kaya sila yung nakikita natin. Pag fall season, mababa ang level ng chlorophyll ng mga halaman. Kaya nag-iiba ang kulay niya. Alright? So, say for example, we have mayana and pea plant. So I hope that we can see this in our garden, okay, our parents' garden or anywhere else. Sir Noy, are they not photosynthesizing so they're not green? Not really. Okay, it's such that they are not color green because the dominant pigment in the plant is not chlorophyll. So it's not color green. But for most plants, the dominant pigment is chlorophyll, that's why it's green. We also have these plants. That's why the color of the plants is different. It's because the dominant pigments in their leaves are also different. There are plants that at this particular part of the leaf, Just like the Discaladium, here on the side, the color green means that the chlorophyll level is high. When it comes to the middle, it's already color red, which means that the chlorophyll level is low. So, just to end the first part of our lecture video, all colors to green, you can sit with us. because the other colors In a normal plant that is dominant with chlorophyll, the red, orange, yellow, blue, indigo, and violet are absorbed except for the color green. The green is reflected. The color green is not absorbed. It's a pity. That's why we see that. the reason why plants are color green. Now, as we end our lecture video, let's take a look back on our learning objectives. Let's try to synthesize everything. So for this lecture video, we were able to define photosynthesis through its chemical equation. Okay, so we remember the chemical equation of photosynthesis and that is 6 carbon dioxide plus 6 H2O. Plus sunlight will give us C6H12O6 or carbon, sorry, or glucose plus six molecules of oxygen. We were also able to label the different parts of the plants that performs photosynthesis such as the leaves and the chloroplasts. And we were able to explain the role and importance of pigments, which functions... which functions for the absorption of light, water, light, and carbon dioxide in photosynthesis. Then finally, we were able to evaluate the importance of photosynthesis to life on Earth. So we said in this lecture video that without photosynthesis, there will be no life or there will be no much diversity of life on Earth. Okay, in our next lecture video, We will be talking about the process of photosynthesis, particularly the light-dependent reaction and the light-independent reaction. So the photosynthesis in details. So be able to watch our next lecture video. I'll see you next time. Have a great day.

So before we start our session or our lecture video rather, I'd like to ask this particular question. What distinguishes plants from other organisms right now you're thinking of a particular answer maybe you're thinking of plants are colored green plants cannot move plants are are or can make plants can make their own food rather all right so these are some of some of the things that might arise in your um in your reflection? Well, most of them, or if not all, are correct.

One of the very important characteristics of life that we can get from this question is that plants have this characteristic to make their own food in the process of photosynthesis. And that will be our topic for today's lecture video. So welcome to another lecture video all about photosynthesis.

The title of my lecture video is Life Starts with Photosynthesis. So let's get started. This will be our target competencies for the whole topic on photosynthesis.

So this lecture video is not only composed of one thing. one video but a series of videos discussing and completing the following competencies. Number one, we have to explain the importance of chlorophyll and other pigments.

Then, describe the patterns of electron flow through the light reaction events and describe the significant events of the Calvin cycle. You might wonder what are these terms that somehow are new to me. the light reaction and the calvin cycle we'll take a note that of that when we go to the other lecture videos to be posted in our lecture in our google classroom now to be more specific for our lecture video this will be our learning objectives so number one we have to define photosynthesis through its chemical equation. We know that photosynthesis is... a process and is a chemical reaction between different compounds now as a bio student or as a stem student we have to take a look at this process in detail all right then when we go to another topic called um the cellular respiration we will be checking um And we will be checking its chemical equation and we will try to connect it with the chemical equations of photosynthesis.

Second, we have to label the different parts of the plant that performs photosynthesis such as the leaves and the chloroplasts. So particularly the leaves and specifically the chloroplasts. So we have to go back to our basic science and even in our GenBio 1 session.

the the parts of a plant cell third we have to explain the role and importance of pigments water light and carbon dioxide in photosynthesis so pigments are are not part of the chemical equation but they play a very significant role in the whole process of photosynthesis water light and carbon dioxide made it possible for photosynthesis to occur. Then finally, evaluate the importance of photosynthesis to life on earth. Yes, why does photosynthesis need to be in the world? Or is photosynthesis really that important? Perhaps you already have an idea based on the title of our presentation for this lecture video.

So let's get started. Now I want you to take a look at this photo. Okay, what can you see? May nakikita tayong animals.

What animals can we see? so we can see different mammals such as an antelope an elephant zebra okay and i want you to take a look at what do these animals do in their environment what are they doing in their environment they are eating all right now let's take a look at another photo okay so from from the land going to the deep waters. What can you see?

You can see different corals, different corals of different color and different marine organisms such as different species of fish and other invertebrates as well. Now, why do these organisms gather in a particular area. Perhaps because they have a habitat there, they have a food to eat.

Okay. Now, in both areas, we can see that plants are very important part of the ecosystem. Okay.

Both the aquatic and the terrestrial environments, ecosystems, are feeding on plants. You might not see carnivorous animals or organisms eat plants, but if you remove those organisms that feed on plants, for sure, they will also be erased. I wanted to take a look at this particular illustration. This is a food web of Now this is a food web showing how animals feed on other organisms.

At the base of this illustration, we can see that plants are present. Try to imagine when we remove plants in this food web. What could happen in this food web? Alright, so tama yung naiisip natin.

The food web will eventually collapse. Okay, meaning... If we remove the plants in the food web, the animals that feed on plants will die because of starvation.

And this will cause a domino effect to those organisms that do not feed on plants but rely their food from other organisms. Those that we call the carnivorous organisms. Pero sir, noy.

There are no or little plants found in the aquatic environment. That's right. Okay. We only have limited plants in the aquatic environment. Now, is this also true in the aquatic environment?

Yes. Alright. There might not be, there might be no plants, okay, in the sea.

But there are also organisms that act as a plant, okay? And these plant-like organisms feed or are being eaten by smaller organisms in the sea. Okay?

Like, say, for example, the phytoplanktons, such as the diatoms and the dinoflagellates, They are the source of food of small fishes such as the fish larvae and small fish like the anchovy or dillis. And bigger fish and microorganisms in the sea will feed on these smaller organisms. We do not see sharks feeding on plants. But we see sharks are fish-eating organisms.

Okay? And these fish-eating organisms feed on fish that are plankton-eating organisms. Okay? So, ibig sabihin, okay, in both aquatic and terrestrial ecosystems, may mga nasa base ng food web. If we remove them from the food web, the ecosystem will keep on falling.

Now, diatoms, itong mga phytoplanktons found in the seas are not plants. But they act as a plant. Bakit kaya? Bakit kaya sila tinatawag na plant-like organisms? If you think that because they also make their own food, then you are.

Correct. Okay. Because for today, we are going to talk about photosynthesis. This is a simple illustration of how plants benefit us.

Okay. So plants take up the carbon dioxide that are being exhaled by animals and they transform it to oxygen which we breathe in and which we need inside our body. Not only humans need oxygen but also other organisms, particularly animals.

So photosynthesis is an essential process in our ecosystem. that if we remove photosynthesis from the equation, of our ecosystem, everything will fall down. Alright?

It's as if that if we remove photosynthesis, we also remove plants in the equation. So, if we are asked, what is the importance of photosynthesis in life? Okay. So, why?

What is the importance of photosynthesis in our lives? And that is, photosynthesis is equal to life on Earth. Just imagine a life or a world without plants do photosynthesizing. Where can we get food? Sir Noy, the pigs that are bought in the market.

Okay, that's right. But let's think, where do the pigs get food? yung mga baka, yung isda na kinakain natin, everything will boil down to plants.

So without the plants on Earth, the diversity of organism will not be possible. Again, may buhay pa naman sa mundo kung kahit walang plants. Pero hindi siya magiging diverse, mausbong.

And because it's beautiful like what we have now. Because only microorganisms can thrive without plants and without photosynthesis. Let's continue.

Now, photosynthesis literally means putting together with light. Photosynthesis came from the two words photo meaning light and synthesis meaning putting together. So when plants do photosynthesis, they are putting together the raw materials needed for these processes. And what are these two materials? We have carbon dioxide and water.

So with the use of light, water and carbon dioxide are being put together, not literally but in a in a long important process in order to make In order for plants to make food of their own and at the same time release oxygen for us to breathe in. Okay? So, photosynthesis is an autotropic process. Meaning, in this process, plants are able to make their own food.

Plants, and not only plants, but plant-like organisms such as the phytoplankton. make energy in the form of glucose from sunlight. Let us all recall our discussion on biomolecules.

Glucose is an example of what particular biomolecule? That's right. So that is an example of a carbohydrate. And carbohydrates functions as an energy source for different organisms.

So this is where what we learned in biomolecules that carbohydrates gives energy to different organisms. So plants use sunlight to turn water and carbon dioxide into glucose. Now, this glucose are stored as carbohydrates in their bodies.

So that's why plants are a good source of carbohydrates. For example, the fruits that we eat, the sweetness of the fruit that we eat is the carbohydrates stored by the plant inside their bodies. Okay? Say, for example, another example are vegetables.

Yung patatas na kinakain natin. Okay? So, pag kumakain tayo ng fries, sabi natin, kumakain tayo ng carbohydrates.

So, yung fries, galing yun sa halaman ng patatas. Okay? So, the...

the glucose the carbohydrates stored by the potato plant inside their body are the fries that we buy and we enjoy okay now photosynthesis occurs in plants particularly in the chloroplane in the chloroplast inside the cells of the leaves so if you're asked what do you call the parts of the plant that performs photosynthesis Ang sagot natin ay leaves. So, yung leaves ay photosynthesis machinery of the plant. Okay? Now, inside the plant cells, sa bawat cells ng dahon, mayroong chloroplast para mag-photosynthesize.

Okay? To be more specific, this is where photosynthesis occurs. Inside the chloroplast.

So this is the chemical formula or the chemical equation for photosynthesis. We have 6 carbon dioxide plus 6 water plus sunlight will give us C6H12O6 or glucose plus 6 molecules of oxygen. Let us recall our understanding on chemistry. It says here, may anim na carbon dioxide, okay, plus may anim na water molecules, plus sunlight, okay, kailangan natin ng anim na carbon dioxide, anim na water molecules, at sunlight, para makapag-produce tayo ng isang molecule ng glucose at anim na molecules ng oxygen, okay? just think of it just think of this as a cookbook okay so we need this kind of ingredients so that we can produce plants with glucose and oxygen so you can see here a more creative version of the chemical equation of photosynthesis so again Plants need six molecules of carbon dioxide, six molecules of water, plus sunlight in order to produce one molecule of sugar in the form of glucose plus six molecules of oxygen.

Now, the sunlight that is present in the chemical equation for photosynthesis is. is actually absorbed by one important molecule inside the plant and these are what we call the chlorophyll. Later on, we'll be talking about what is a chlorophyll and what is its function in the plants. And how do we know that a plant has a chlorophyll?

So why is photosynthesis important in... in our ecosystem and not only for the plants. So as you can see on the left side of the screen, a hydrilla plant that is photosynthesizing. So why did we say that this plant is photosynthesizing? Okay, I want you to observe.

We don't see the process itself, but there is one important indicator on why. nasabi natin na nagpo-photosynthesize siya. Alright?

It's because of the bubbles. So, why is photosynthesis important? in plants. So number one, because photosynthesis makes organic molecules out of inorganic materials such as carbon dioxide and water.

So these organic molecules is a carbohydrate that is badly needed by plants in order to function. And in terms of energy transformation, This glucose or carbohydrates, this is what we get from plants. so that our body systems and cells can function.

Second, it begins all food chain and food web. As I said, without plants, there will be no food for our herbivores and other animals that rely on plants, including humans. Then also, One important indicator of photosynthesis is the gas molecule, which is found in this image. The bubbles that we see there, these are oxygen gases produced by the plant after photosynthesizing.

Let me emphasize that plants produce oxygen because oxygen is a byproduct of photosynthesis. What I mean by byproduct is waste material sya ng photosynthesis. O diba, napakasyala. Okay, waste product ng plants, yung oxygen na needed natin. At the same time, tayong mga animals, okay, ano yung waste product natin?

Na gas. Okay, hindi utot, pero These are carbon dioxide. Okay, yung carbon dioxide na badly needed ng plants para mag photosynthesize, waste material lang natin yun.

Alright? So, yun. So, photosynthesis starts to ecological food web.

So, the sun is the source of energy for most living things. Now, plants such as grass use this energy from the sun to make their own food. then An herbivore such as the zebra obtains energy by eating the grass. Then, later on, the lion obtains energy by feeding on the zebra. So, ibig sabihin, okay, para siyang gears na kapag hindi gumana yung isang gear, hindi na iikot yung ibang gears.

Okay? We are all connected. Okay? Ecologically speaking.

So kapag walang araw, If there's no light, plants will not photosynthesize. Zebra will not eat either. Lions will not eat either. If one of these does not work, it will have effects on the next processes. So let's try to review.

So what is the process that makes the sun's energy to make simple sugars? This is photosynthesis. And what do we call these simple sugars?

This is glucose. What are the molecules that absorb energy from the sun? It's not water. It's not also carbon dioxide.

These are chlorophyll. And what is the general formula of photosynthesis? We need the complete general formula.

That is 6 CO2 or carbon dioxide plus 6 H2O or water plus sunlight will give us C6H12O6 or glucose plus oxygen. 6 oxygen molecules. So let's try to understand the leaves.

So the leaves are the main organs for photosynthesis. Thus they are called as besides for food synthesis because technically they are food factories of the plants. This is where the plants photosynthesize. Thus this is their main organ where they make their own food particularly the glucose. But Let it be known that it is not always the leaves that do the photosynthesis.

green parts of the plants are areas for photosynthesis also. So, we can see that parts of the plant that are color green, they are also suspected parts of the plant that do photosynthesis. So, sometimes, there are plants that have no leaves, but they still continue to thrive because it's not only the leaves that do photosynthesis.

Alright? So, that's it. Even the stems, the roots, and even flowers and fruits can do photosynthesis. Now, why are leaves color green? It's because they contain chloroplasts, which contains chlorophyll, which are sites for photosynthesis also.

The main organelle, if the leaves is the organ for photosynthesis, The chloroplasts are the organelles for photosynthesis. That means deep within the plant are chloroplasts that functions for this particular process. So as you can see, these are different species of plants that we can see.

So we have here catmone. So if we can see, Catmon's color is green. dahon. So again, why are they green? Because they are areas for photosynthesis.

Same goes with bitaog. The fruits of bitaog are colored green. So nagpo-photosynthesize din itong prutas na to. We also have an orchid at the lower left side of the screen where the roots are also colored green, meaning they are filled with a lot of chloroplasts.

and chlorophyll that functions in the absorption of light so that they can photosynthesize. Now let's take a look at the different parts of the leaves. What are the different parts of the leaves?

So first, we have the cuticle. So the cuticle is a waxy layer that protects the leaves from excessive loss of water. The leaves are exposed to the sunlight.

or in many cases they are directly exposed to the sunlight. Thus, in order to prevent dehydration, many many leaves had evolved and had cuticles on the upper side of the leaves. So also, below the cuticle, we have that. epidermis.

So the epidermis covers the leaves which also gives protection to the leaves. So the epidermis is not only found on the upper side of the plant but also at the lower side of the plant. It's like we're just covering it. If you put our arm horizontally, the ones exposed in the sun is is the epidermis. While the part of our skin that is not exposed to the sun is still called as the epidermis.

So their main function is to protect the leaves and also prevent it from losing excessive water. Remember that plants need water in order to live. So since they are exposed to the sunlight, they have this particular adaptation.

So as you can see, we have a Hoya species and a Calathea species on your screen. If we're going to take a look at these two plants, we'll think that the leaves of these two plants are like plastic. Because there is a very waxy layer. and on on the upper side of the of their leaves now the waxy or the shiny part of the leaves is shiny because they are covered with cuticle so at the middle layer of the leaf is the mesophyll from the word meso meaning middle so this is the inner layer of the leaves which functions for the actual photosynthesis dito na yung pinaka photosynthesis nangyayari.

And it has a lot of chloroplasts. On the lower, on the underneath, the leaves, at the back of the leaves, these have stomata. So the stomata allows gas to enter and leave from and to the leaves. So here, gases come out and enter. So what are the gases that come out and enter?

We have carbon dioxide and water. Because remember that carbon dioxide has to enter the leaf in order for photosynthesis to occur. Under the microscope, if we look at the leaf, under the microscope, there is something that opens and closes. These are the stomata. So here, this is an illustration of an open stomata.

And on the other hand, this is a micrograph of a stomata. So nasaan dito yung stomata? Yan pong mga bilog-bilog.

If we will be having another micrograph of the stomata, eto yun. Para siyang mga mata. Kaya isipin na lang natin stomata, mata.

Nagbubukas, nagsasara. Pero anong function ng stomata? Hindi siya tulad ng mata natin para makakita.

Yung stomata ng mga halaman, They open and close in order for gas exchange to happen. Carbon dioxide will enter here and carbon dioxide will also come out here. Then, let's talk about the mesophyll.

The mesophyll, this is still divided into two layers. The first one is what we call the palisade mesophyll, which contains a lot of chloroplasts. And they are adapted. for the absorption of light efficiently.

So remember, at this part of the plant where there's a cuticle, this is where the sun is the most active. Okay? So after the cuticle, there's an epidermis.

Okay? And below the epidermis is the palisade mesophyll. Okay? If we can see the palisade mesophyll, In comparison with the spongy mesophyll, they have different structure of the cells. So why do they look like this?

Because this is where the sunlight is. So when the sunlight hits here, it directly absorbs the chloroplasts. and the spongy meso feel okay They are located below, near the stomata because they aid in the gas exchange of photosynthesis.

The stomata is also below because the stomata cannot escape from the area where they are sunbathing. Because if the stomata escapes, they will be prone to loss of water. That is why adaptation of plants is important.

Sa ilalim nagkakaroon ng gas exchange. Then, one observable part of the plant are the vascular bundles, the veins of the plant. So there are two types of veins which functions for the transportation of materials inside the plant.

So we have the phluem. And we also have the xylem. So, fluem is a particular vascular vein in the plant that functions for the distribution of organic materials. Okay? The glucose that Chloroplasts produce after photosynthesis is transported by fluem.

Okay, para lang. factory. When the product is made, there are delivery channels to pass through the products and it will go to different areas.

For example, when glucose is produced, the fluem, I mean the glucose will go to the fluem and the fluem will distribute to different parts of the plant. If you want, um... transports organic materials or the food, xylem transports and distributes water.

So from the roots, how does the water that was absorbed by the roots reach the plants? It's because of the xylem. So so that we won't get confused, fluem transports food, Tandaan natin, food sounds like F, fluem, yung first syllable sounds like letter F. Fluem, food. On the other hand, xylem, um, xylem, this remutes water.

What's the letter before letter X? It's W. Okay, xylem starts with letter X, and the letter before X is W, so water. Okay?

So these are the different parts of the leaves. Okay, let's try to review so we won't forget. So the first part is the cuticle.

So the cuticle is again a waxy layer that protects the plants from excessive heat in order for the plant not to lose a lot of water. Okay, this is usually the part that is very exposed to the sun. So to avoid the...

loss of water, the plants adapted to their environment and produced cuticles. Then we also have the upper epidermis, the ones that is just below the cuticle. The middle layer that we call the mesophyll. The lower epidermis, the stomata, which is part of the lower epidermis the stomata functions for the opening and closing of the leaves and for gas exchange the palisade mesophyll and the spongy mesophyll so let's see what's the difference between the two okay i wanted to take a look at the structure of palisade mesophyll and spongy mesophyll So that we can easily identify the two main divisions of the mesophyll. We also have the vascular bundles which comprises the xylem which transports food and phluem which transports the food materials or we can also call that as the organic materials or carbohydrates.

Let's become more specific by taking a look at the different parts of the chloroplast. So again, one of the major differences of animal cell from plant cell is the presence of chloroplast. Because it's only the plants and plant-like organisms that can photosynthesize. No animal can photosynthesize so far.

Okay, then. chloroplast contains chlorophyll which is a pigment that absorbs all light except for green so that's why we see green because the chlorophyll absorbs all color but reflects the color green so the reason why um the reason why um plants are generally green because yung chloroplast, meron silang chlorophyll na inaabsorb niya lahat ng chloroplast. kulay ng ilaw except for color green. That green called the green light is being reflected back to its environment. So the encircled organs are the chloroplasts.

So these are the parts of the chloroplast when we take a look at it in detail. So it has an inner membrane, the outer membrane is the chloroplast. We also have the thylakoid, the lamellae, the stroma.

The stroma is the fluid inside the chloroplast. The granum as well. So what is the difference between the granum and the thylakoid?

The thylakoid is the individual that is round. And when the thylakoids are stuck, we call them granum. The plural of granum is grana. So, just imagine the thylakoids as pancakes.

A single pancake is called thylakoids. When we cut the pancakes into pieces, we call them granum. Okay, pag maraming stacks ng pancakes, grana na ang tawag natin. and we also have the lumen.

The lumen is the innermost part of the thylakoid. So the thylakoid contains the photosynthetic pigments. So what are these photosynthetic pigments? We have the chlorophyll. Remember that photosynthetic pigments are Um, are the light absorbing molecules found in plants.

And these plants mostly contain the chlorophyll, which is a particular example of a photosynthetic pigment. So the granum or the grana are stocks of thylakoids. The stroma is a fluid structure found in the thylakoid okay and the lamellae connects the granum together okay um let's continue now um wild type plants have 80 to 100 chloroplasts per mesophyll cell so just imagine how many i know how many chloroplasts are there in one single leaf sa isang sel pa lang ng dahon, meron na siyang ano, 80 to 100 chloroplasts, what more than one leaf? So, the number of chloroplasts is now millions.

Now, under the light microscope, the chloroplasts are the ones we see in the green circles. Okay, on the other hand, under the light microscope, a chloroplast looks like this one. So leaves are green because they contain the pigment chlorophyll.

So they are the reason why plants are green. Now leaves have a large surface area to absorb as much light as possible. So this is the reason why leaves are flat.

Why they are not spherical or cubic in shape or pyramid in shape of leaves? is because So that they have more light to absorb, they are flat. Okay, so that they have much surface area. Then, chloroplasts are solar-powered chemical factories. Their thylakoids transform light into chemical energies of ATP and NADPH.

So, that's it. The ATP is formed by the thylakoids. and we know that ATP is our energy currency.

This is the energy of the plant. So light is a form of an electromagnet energy that is also called as an electromagnet radiation. So we have a physics concept here that light is an energy. It's a form of energy.

Now We have to discuss light because we have to give a reason kung bakit color green ang plants. Now, visible light contains wavelengths that produce color. If meron tayong prism, kapag tinamaan niyo ng ilaw, it will give us different colors of light.

Okay? Hindi lang puti ang ilaw. visible light but it is composed of different colors.

Now light behaves as though it contains discrete particles called photons. So we believe that light is composed of particles that we call photons. Now pigments are substances that absorb these visible lights.

Now different pigments absorb different wavelengths. And wavelengths that are not absorbed are reflected or transmitted. Some examples of pigments are chlorophyll, anthocyanin, and carotinine. So yung pinaka common sa plants is the chlorophyll. Si chlorophyll, they appear green because they reflect and transmit green light.

Inaabsorb ni chlorophyll lahat ng kulay ng ilaw except for color green. Remember, sa prism, In the prism, the light that our eyes see, we think it's just white. But in reality, it's different colors. It's a ROYGBIM.

The plant absorbs the red, orange, yellow, blue, indigo, and violet. But it doesn't absorb the green. Instead of absorbing it, it reflects it. Okay? There are some plants also that are not color green.

Like say for example, this particular leaf. This particular leaf is color green because dominantly, it has anthocyanins. Anthocyanins absorb, it's a kind of pigment that absorbs all colors except for red. So, It has a red color. Carotinins, carotin, sorry, carotins, absorbs all color except for yellow or orange.

Kaya may iba't-ibang kulay ng dahon tayo. Okay? Hindi lang green, pero most plants are green color. The rest are other colors. Ayan.

So, this is a very good example of what i am saying earlier so see light coming from the sun okay will be will be absorbed by the will be absorbed by the chloroplast tapos my chlorophyll and my thylakoids so you can even cool in an an email you absorb your except for color green see color green It reflects or transmits. If we notice, later on, the light is not of any other color except for color green. That's why we see the plant as color green.

Because again, chlorophyll absorbs all colors except for color green. There. So this is a graph showing the different pigments of plants.

So we can see here that they absorb a particular color. Like say for example, I want you to focus on chlorophyll A and chlorophyll B. We can see here that their absorption is high when it comes to blue color. But when it comes to green color, their absorption is very low.

They don't really absorb the green color. But they absorb other colors more except for green. Okay?

When it comes to orange and red, they absorb it again. Okay? Let's take a look at this carotenoids.

So carotenoids is another pigment. It absorbs all colors except for The colors are orange, yellow, until red. You're reflecting this color.

That's why it looks orange. This is also the same example earlier. Plants produce several different light-absorbing pigments.

Each photosynthetic pigment absorbs and reflects specific wavelengths. Again, let's go back to chlorophyll. When it comes to chlorophyll, it absorbs the colors of purple, blue, but as the graph shows, it decreases when it goes to green.

Then it increases again when it goes to yellow, orange, and until red. So technically, we can see here that chlorophyll is not absorbed by the green color. Instead of absorbing the green color, this is reflected. Okay?

That's why we can see color green. So Sir Noy, why in other countries, when there's a fall, or fall season na, bakit nag-iiba yung kulay ng halaman? Very good question.

So, yun. Generally, nag-iiba yung kulay ng mga halaman ng leaves, particularly during fall, kasi during fall season, brine-breakdown ng halaman yung chlorophyll. So, walang chlorophyll or na uubos yung chlorophyll ng mga ng mga halaman pagdating ng fall. Since wala masyadong chlorophyll ang halaman, lumilitaw yung ibang pigments sa loob ng halaman such as the carotenoids and other pigments. So as we can see, in the fall season, chlorophyll A and B molecules are broken down and stored in branches.

So they are being broken down, wala sila sa dahon, so lumilitaw yung ibang pigment. such as the carotenoids. Okay?

Pag spring season, okay, yung mga chlorophyll, nando doon sila sa mga halaman. Kaya sila, mataas ang level ng chlorophyll. Kaya sila yung nakikita natin. Pag fall season, mababa ang level ng chlorophyll ng mga halaman.

Kaya nag-iiba ang kulay niya. Alright? So, say for example, we have mayana and pea plant. So I hope that we can see this in our garden, okay, our parents' garden or anywhere else. Sir Noy, are they not photosynthesizing so they're not green?

Not really. Okay, it's such that they are not color green because the dominant pigment in the plant is not chlorophyll. So it's not color green. But for most plants, the dominant pigment is chlorophyll, that's why it's green. We also have these plants.

That's why the color of the plants is different. It's because the dominant pigments in their leaves are also different. There are plants that at this particular part of the leaf, Just like the Discaladium, here on the side, the color green means that the chlorophyll level is high. When it comes to the middle, it's already color red, which means that the chlorophyll level is low.

So, just to end the first part of our lecture video, all colors to green, you can sit with us. because the other colors In a normal plant that is dominant with chlorophyll, the red, orange, yellow, blue, indigo, and violet are absorbed except for the color green. The green is reflected. The color green is not absorbed.

It's a pity. That's why we see that. the reason why plants are color green.

Now, as we end our lecture video, let's take a look back on our learning objectives. Let's try to synthesize everything. So for this lecture video, we were able to define photosynthesis through its chemical equation. Okay, so we remember the chemical equation of photosynthesis and that is 6 carbon dioxide plus 6 H2O.

Plus sunlight will give us C6H12O6 or carbon, sorry, or glucose plus six molecules of oxygen. We were also able to label the different parts of the plants that performs photosynthesis such as the leaves and the chloroplasts. And we were able to explain the role and importance of pigments, which functions...

which functions for the absorption of light, water, light, and carbon dioxide in photosynthesis. Then finally, we were able to evaluate the importance of photosynthesis to life on Earth. So we said in this lecture video that without photosynthesis, there will be no life or there will be no much diversity of life on Earth. Okay, in our next lecture video, We will be talking about the process of photosynthesis, particularly the light-dependent reaction and the light-independent reaction. So the photosynthesis in details.

So be able to watch our next lecture video. I'll see you next time. Have a great day.

Transcript for:Photosynthesis Overview

Transcript for:
Photosynthesis Overview