Transcript for:
Understanding Eukaryotic Cell Organelles

the next series of organelles that exist inside eukaryotic cells that we're going to discuss in detail include the vacuole lysosomes as well as the two types of microbodies peroxisomes and glyoxosomes so let's begin by discussing what the vacuole is where the vacuoles are found and what the function of the vacuole is so vacuoles are membrane enclosed organelles so they contain a phospholipid bilayer and vacuoles are predominantly found in plant cells as well as fungal cells but they can also be found in animal cells now vacuoles are found inside the cytoplasm of our cell and the functionality the shape and size of vacuoles depends on the type of cell that we are examining so let's begin by examining plant cells so in plant cells the vacuole serves three important purposes one it basically stores the water that is used by the cell two it creates and maintains the hydrostatic pressure the target pressure that gives the plant cell its ability to resist forces as well as pressure and three our vacuole basically creates an acidic environment that allows hydrolytic enzymes to break down macromolecules as well as waste products so generally in Plants vacuoles function to store harmful materials and waste products store water and maintain hydrostatic pressure also known as turgor pressure and the and our acidic environment inside plant cells is basically a result of the integral proteins that are found inside the phospholipid layer of our plant vacuoles basically those proteins inside the phospholipid bilayer pump H ions into our vacuole and that increases the acidity and lowers our pH and that gives these enzymes the hydrolytic enzyme stability to break down the waste products stored inside vacuoles now in animal cells vacuoles are much smaller they do not store as much water and they basically function in aiding endocytotic and endo and exocyte processes remember endocytosis is the process by which the cell engulfs extracellular material and exocytosis is the process by which the animal cell spits out wasteful types of products now let's move on to our lysosomes so what exactly is a lysosome well a lysosome is a spherically shaped membrane enclosed organelle that are found in animal cells all the recent evidence shows that they can also be found in plant cells so basically lysosomes just like vacuoles contain an acidic environment that is created as a result of the integral proteins found inside the phospholipid bilayer of the lysosomes so the H ions are pumped from the cytosol into the lysosome and that creates that low PH about 4.8 to 5 pH now this low PH allows our hydrolytic enzymes also known as acid hydrolase enzymes to basically break down the four different types of macromolecules and this includes lipids proteins nuclei acids as well as carbohydrates so all these different types of macromolecules as well as other type of waste products and materials are broken down inside our lysosomes as a result of these different types of enzymes now because the lysosome contains these hydrolytic enzymes and it also contains a low PH the lysosome also has the ability to basically destroy that cell so if the lysosome decides to basically rupture it releases all these harmful types of things inside the cytosol and that can kill the cell now why exactly would a cell want to kill itself well imagine that the DNA of the cell is somehow damaged and that could cause serious problems so to basically uh kill off the cell the lysosome can rupture and that destroys the cell as well as killing off that type of DNA that was basically um uh damaged and this process is known as autolysis now where exactly are lysosomes produced and where are the proteins inside the lysosomes produced so basically the proteins the enzymatic proteins inside the lysosomes are produced in the rough endoplasmic reticulum and once they are produced they travel through the smooth endoplasmic material and eventually end up in the Golgi apparatus and the Golgi apparel is basically modifies those hydrolytic enzymes and then releases them inside secretory vesicles which then fuse with endosomes such as for example thangosomes and that creates our lysosome so basically lysosomes can also be used inside cells to destroy things like bacteria so inside our inside our immune system we have cell known as phagocytes and those phagocytes undergo a process known as phagocytosis so engulfing things like bacteria and the lysosomes can fuse with the phagosome that contains our bacterial cell and that can destroy our bacterial cells so we can see how lysosomes can be very important inside animal cells now let's move on to a type of organelle known as the micro body so microbodies are generally small spherical membrane enclosed organelles that contain a single phospholipid bilayer and there are two types of microbodies we have peroxisomes as well as glyoxosomes and let's begin by defining what a peroxisome is so peroxisomes are microbodies that carry out the different types of oxidation reduction reactions found inside the cell and it also produces a harmful byproduct known as hydrogen peroxide which is then further broken down by using different types of enzymes so there are many different types of protein enzymes found inside the peroxisone and one of the major function one of the major roles of the peroxisome is to basically break down fatty acids into a type of energy source so it basically creates ATP so the mitochondria is not the only place in the animal cell where we create a ATP peroxisomes can also create ATP by breaking down the fatty acids now not only can we break down fatty acids inside peroxisomes we can also synthesize lipids for example cholesterol inside our peroxisomes and another important function of the peroxisome is to basically detoxify our cell from different types of toxins as well as drugs so we have have different types of protein enzymes found inside the peroxisome that that basically function to break down fatty acids to create lipids such as cholesterol as well as detoxify our cell break down toxin as well as drugs such as for example alcohol so peroxisomes are especially important in the cells found in the liver inside our bodies now what exactly is the major difference between a lysosome and our peroxisome so the hydrolytic enzymes found inside lysosomes are generated in the rough endoplasmic reticulum but unlike lysosomes the enzymatic proteins inside peroxisomes are not formed inside the rough endoplasmic reticulum they are formed inside the free ribosomes inside the cytosol of the cell so basically once we form those proteins inside the free ribosomes the proteins will basically go inside our peroxisome and this is the major difference between lysosomes and our peroxisomes now peroxisomes can be found in both animals as well as plants in animals the peroxisome is called a peroxisome but in Plants the peroxisome is known as a glyoxisome so the glyoxosome is simply a specialized type of peroxisome that is found in plant cells especially in germinating plant cell and it also found and it's also found in fungal cells so glyoxosomes are responsible for oxidizing fatty acids into intermediates that eventually become sugar so basically before our plant cell matures into the mature plant cell our glyoxosome is the major source of the production of sugars and until the chloroplast of the plant cells mature the glyoxosome is the organelle that is response able for producing sugar from fatty acids so we see that peroxisomes and glyoxosomes are basically microbodies whose major function is to break down fatty acids into a usable source of energy now peroxisome can also break down different types of toxins as well as drugs and it can also synthesize lipids such as cholesterol now lysosomes are spherically shaped membrane enclosed organelles that contain hydrolytic enzymes which are formed inside the rough endoplasmic reticulum and this organelle basically acts to break down the different types of macromolecules as well as breakdown harmful materials as well as bacterial cells and our vacuole is predominantly found in plant cells so it stores water it maintains hydrostatic pressure turgor pressure and it also contains a low PH just like the lysosome and so it acts to kill off different types of toxic things and waste products now vacuoles are predominantly found in plant cells can also be found in animal cells but the functionality differs lysosomes are predominantly believed to be found in animal cells also all the recent evidence does show that lysosomes might also be found in animal cells and microbodies are found in both animal cells and plant cells in animal cells our micro body is called the peroxisome while in plant cells the peroxisome is called a glyoxisome