foreign [Music] that we are going to study is life processes the life processes helps the organisms to maintain their bodies as well as to repair their bodies that means the organisms cannot survive without the life processes do you know all living things are made up of cells cells are made up of molecules to keep a cell alive it needs to be maintained well and repaid from time to time for this repair and maintenance two things are to be done one supply of new materials and two removal of waste and unwanted materials from these cells these two tasks are achieved by life processes in this chapter we will learn about four important life processes they are One Nutrition two respiration three transportation and four excretion first life process nutrition it is a life process by which organisms are able to obtain their food and can convert that food into nutrients these nutrients helps the organisms in their growth and repair and maintenance of their bodies the second process is respiration in this process organisms obtain oxygen from their surroundings and releases carbon dioxide side out of their bodies respiration also releases energy from the food molecules like glucose third life process is transportation this process helps in the transport of useful materials like glucose oxygen and toxic materials like carbon dioxide urea Etc cells get oxygen and nutrients by these three life processes cells use these materials for production of energy and to make new complex molecules in these cellular reactions toxic materials like carbon dioxide and urea are produced these toxic materials are to be sent out of the body then who does this job exclusion excretion is another important life process in which toxic wastes produced in our body are sent out nutrition in plants plants prepare their own food by using simple inorganic materials like water carbon dioxide and sunlight this process is called photosynthesis photo means light and synthesis means making or preparation now let us see the definition of photosynthesis photosynthesis is the process by which plants use sunlight water and carbon dioxide to produce oxygen and energy in the form of glucose that means in photosynthesis water carbon dioxide and sunlight or the raw materials glucose and oxygen are the products we know that photosynthesis takes place inside the green leaves but do you know the exact location of photosynthesis inside the leaf if we look at the cross section of any Leaf under a microscope we will be able to see this kind of green structures these are chloroplasts these are the structures in which photosynthesis takes place now let us see how plants get their raw materials for photosynthesis plants get the carbon dioxide through stomata stomata are the tiny pores present on the underside of the leaf plants get water from the soil through roots sunlight enters the chloroplast through the upper surface of the leaf now let us see the different steps of the process photosynthesis step 1. chloroplasts have a green pigment called chlorophyll this chlorophyll molecule gets activated by sunlight step 2. this light activated chlorophyll splits the water molecules into hydrogen and oxygen step 3. the hydrogen produced in Step 2 reacts with carbon dioxide and forms glucose apart from glucose plants also make proteins in their bodies plants need nitrogen to make protein molecules plants get this nitrogen from this soil nitrogen is present in the soil in the form of nitrites and nitrates but from where do these nitrites and nitrates reach the soil the nitrogen fixing bacteria present in the soil converts the atmospheric nitrogen into nitrites and nitrates this is all about the nutrition in plants nutrition in human beings food enters our body through mouth our digestive system begins with mouth and ends with anus different parts of the digestive system are arranged like a long coiled tube this tube is called Elementary Canal the food inside the mouth is made into a paste by the action of teeth and saliva saliva is a fluid that makes the food soft and wet saliva has an enzyme called as salivary amylase it digests the starch partially the food is well chewed in the mouth and it passes down into the stomach through esophagus the rhythmic contractions of the esophagus helps the downward movement of the food these rhythmic contractions are called peristalatic movements this is stomach it is a hollow muscular organ gastric glands present in the walls of the stomach they produce gastric juice the gastric juice has different compounds in it they help the stomach in the process of digestion let us see different components of this gastric juice gastric juice has pepsin hydrochloric acid and mucus in it pepsin is a protein digesting enzyme the medium of the stomach should be acidic for the proper action of the pepsin so the medium of the stomach is made acidic by hydrochloric acid HCL is a strong acid it can cause damage to the stomach walls a thick layer of mucus protects the walls of the stomach from the action of HCL at the end of the stomach there is a muscular sphincter called as pyloric sphincter this sphincter releases the partly digested food slowly into this small intestine small intestine is the longest part of the elementary Canal it is highly coiled to fit in less space pancreas s secretes pancreatic juice intestinal glands secrete intestinal juice and liver secretes bile juice into the small intestine pancreatic juice and intestinal juice have enzymes like trypsin lipase pancreatic amylase peptidases and nucleosis these enzymes help in the digestion of carbohydrates fats and proteins the bile juice that comes from liver does two important jobs one emulsification of fats means converting the bigger fat droplets into smaller fat droplets by doing this the surface area of the fat droplets increases due to increase its surface area enzymes can digest these fat droplets more efficiently the second job of bile is to make the intestinal pH alkaline in this small intestine alkaline medium is required for the digestion of carbohydrates the digestion of the food gets completed in the small intestine in the complete process of digestion carbohydrates are converted to sugars proteins are converted to amino acids fats are converted to fatty acids and glycerol the nutrients that are formed in the digestion reaches the cells through the blood circulatory system but how do these nutrients enter the blood circulatory system absorption of nutrients small intestine has numerous finger-like projections on its inner surface these finger-like projections are called Villi blood vessels and lymph whistles are present inside these Villi nutrients get absorbed into these vessels and enters the bloodstream undigested food enters into the large intestine the water present in this undigested food is absorbed into the blood remaining undigested waste is excreted out through anus respiration now we will study about respiration respiration is one more important life process nutrition helps to get the nutrients like glucose from food whereas respiration helps in the release of energy from nutrients like glucose in some organisms oxygen is needed for the process of respiration the respiration that takes place in the presence of oxygen is called aerobic respiration in aerobic respiration one glucose molecule splits into two pyruvic acid molecules this step takes place in the cytoplasm of the cell now this pyruvic acid molecules enters the mitochondria inside the mitochondria these pyruvic acid molecules turn into water and carbon dioxide in this process energy is released this energy gets packed in ATP molecules the full form of ATP is adenosine triphosphate these atps supply energy to different activities of these cells for this reason these atps are called as cell currency in some organisms oxygen is not needed for respiration this type of respiration is called anaerobic respiration but in anaerobic respiration less atps are released when compared with aerobic respiration anaerobic respiration is observed in organisms like bacteria and in yeast sometimes even in our bodies anaerobic respiration takes place why while doing vigorous exercise the oxygen levels decrease in our muscle cells this leads to oxygen deprivation and leads to anaerobic respiration in anaerobic respiration pyruvic acid molecules turns into lactic acid by releasing energy the buildup of this lactic acid in the muscle tissue due to anaerobic respiration leads to muscle soreness or muscle pain in organisms like yeast during aerobic respiration pyruvic acid molecules are converted into ethanol this process is called as alcoholic fermentation the energy that is released in aerobic respiration is greater than the energy released in the aerobic respiration but for the process of aerobic respiration a continuous supply of oxygen is needed but how do aerobic organisms gets the continuous supply of oxygen it is done by breathing breathing plants have small pores on their leaves called stomata for the exchange of gases animals need special respiratory organs for the exchange of gases then how do humans get the oxygen let us see breathing is an important part of respiration breathing helps to obtain oxygen from these surroundings human respiratory system is well designed to absorb oxygen from the atmosphere let us see the structural and functional importance of human respiratory system human respiratory system begins with a pair of nostrils air enters the nose through the nostrils thin hairs present in the nasal passage filters the dust particles that we breathe in the nasal cavity is lined with mucus and it makes the air moist and humid now this moist air enters the windpipe windpipe is also called as trachea it is supported by c-shaped cartilaginous Rings these Rings support the trachea and helps to keep it open all the time windpipe divides into two branches these branches are called bronchi they are further divided into fine branches called bronchioles finally these bronchioles are attached to small balloon-like structures these balloon-like structures are called alveoli the wall of the alveoli has a network of blood capillaries here the exchange of gases takes place between the blood and alveoli the blood that comes from the body parts has more carbon dioxide in it the air that enter the alveoli has more oxygen in it due to this difference the exchange of gases takes place between the blood and the alveoli oxygen is transported by a pigment called as hemoglobin which is present in the RBC of blood carbon dioxide is transported by blood in dissolved now let us look at the human transport system transportation is an important life process materials required for nutrition respiration and excretion are supplied by the transport system hot blood and blood vessels are the three important parts of the human transport system just like how an electric motor pumps water in the pipes heart pumps the blood into the blood vessels our heart is a muscular organ it is in the size of our fist heart does two important jobs the first job is to collect deoxygenated blood from the different parts of the body and send it to the lungs for the oxygenation this task is done by the right side chambers of the heart the second job is to collect the oxygenated blood from the lungs and Supply it to the different parts of the body this task is done by the left side chambers of the heart but these two tasks are to be performed at the same time at first left atrium and right atrium gets relaxed the left atrium gets the oxygenated blood from lungs right atrium gets the deoxygenated blood from the body parts now both these Chambers get contracted and pump the blood into the bottom Chambers now the left ventricle get contracted and sends the oxygenated blood to the body parts at the same time right ventricle pumps the deoxygenated blood into lungs animals like birds and mammals have a four chambered heart in the circulatory system of these organisms oxygenated and deoxygenated blood circulates separately the blood travels through the heart twice in one complete cycle of blood circulation one time between the heart and lungs and the second time between the heart and body parts so this type of circulation is called double circuit Circle relation or double circulation now we will study about the blood and blood vessels in our body we have three different types of blood vessels named as arteries veins and capillaries arteries carry the oxygenated blood from heart to different parts of the body heart pumps the blood into arteries with great pressure arteries have thick and elastic walls to resist this blood pressure veins collect the deoxygenated blood from the body parts and carry it to the heart veins do not have thick walls since the pressure of blood is low in veins but veins have valves in them due to these valves the flow of blood takes place only in one direction to supply the materials to cells arteries split into thin fine tubules called capillaries these capillaries join together to form the veins if all blood vessels are cut in any accident blood flows out through these blood vessels this leads to loss of blood to stop the bleeding blood blood platelets move to the site of the leakage and plug the cut temporarily just like blood circulatory system we have another system in our body called as lymphatic system lymph Flows In This lymphatic system lymph is a colorless fluid the liquid part of the blood is called plasma this plasma escapes out the circulatory system through this small pores present in the walls of the capillaries this fluid gets accumulated in the intercellular spaces of different tissues later this fluid becomes the lymph this lymph enters the lymphatic vessels through the lymph capillaries finally these lymph vessels open into the large veins lymphatic system does two important jobs the first job of lymph is to absorb the digested fats in the intestines the second job is to collect the extracellular fluid and deposits it into the bloodstream these are the important points of the animal transport system now we will study about the plant transport system the requirement of energy in plants is less that's why they have a slow transport system in Plants the transport of food and water takes place by two different types of tissues they are xylem and phloem the food that is prepared in the leaves of the plants during photosynthesis has to be supplied to different parts of the plants this process is called as translocation the translocation of food materials like glucose takes place through phloem tissue in Plants this translocation takes place in both upwards and in downwards directions energy is required for the process of translocation cells get this energy from ATP at first with the use of energy from ATP sucrose enters the phloem tissue then the osmotic pressure inside the phloem tissue increases now due to this osmotic pressure water enters the phloem tissues now with this pressure food materials are taken to to different tissues of the plants phloem transports the food as per the requirements of the plants for example in Spring season buds need food material for flowering then the phloem transports the food from stem or root the transportation of water takes place through xylem tissues in plants plant parts like stems branches roots and leaves have xylem vessels and tracheids in them now we will see how the water enters into the roots the cells of the roots that comes in contact with this soil actively takes the ions from the soil into them due to this kind of active transport of ions the difference in the concentration of ions develops between soil and root cells to balance this difference water enters the roots during night the transportation of water in Plants takes place through root pressure during day time plants keep their stomata open for the process of transpiration due to this transpiration water moves up in the xylem now we will discuss about the human excretory system cells while carrying out their activities they produce toxic nitrogenous substances like urea and uric acid these compounds are to be eliminated from our body this job is done by the excretory system blood collects and Carries these toxic materials to the excretory system for filtration human excretory system has two kidneys two ureters one urinary bladder and one urethra in it nephrons are the structural and functional units of the kidney these are the tiny structures that filter the blood each nephron has a tuft of capillaries called glomerulus and a cup-like structure called Bowman's capsule nephrons filter the blood and removes the waste like urea uric acid creatinine Etc useful materials like glucose amino acids and salts also get filtered in the Bowman's capsule but later they get reabsorbed back into the blood circulatory system filtered wastes along with water is called as urine it enters the urinary bladder through ureters once the bladder is full it triggers the sensation of urination when we relax the muscles of the urinary bladder then the urine flows out through the urethra these are the important points of the life process thanks for watching [Music] thank you