ORAGANELLES

Organelles The cell membrane is an extremely important part of the cell. The animal and plant cells are held together by the cell membrane. The cell membrane is a lipid bilayer containing proteins, cholesterol, and oligosaccharides. The cell membrane functions as a selective barrier for entry and exit of substances. Without the cell membrane then the cell would fall apart and there would be no more cells. Vacuoles are also important to a cell. Most mature plant cells have a central vacuole, which often takes up more than 90% of the cell. Without a vacuole than a cell would be a lot smaller than they are now, even though they are really small now. Vacuoles in plants can store waste products and break them down so the waste doesn’t harm the cell. The vacuoles also store different molecules a cell needs to survive. The vacuoles contain foods and oil. In a plant, when the vacuoles are full of water, then the plant stands straight up. When the plant’s vacuoles don’t contain a lot of water then the plant will wilt, because the cell wall is the only thing holding up the plant. Without the vacuoles then the cell could possibly burst from having too much water, or the cell could not get enough energy, because there would be no extra stored food. Plants would always be wilted, because there would be no vacuole full of water to hold the plant up straight. White blood cells consume bacterium and destroy it. When this takes place the white blood cell’s lysosomes do most of the work. They combine with the vesicle of engulfed material and release digestive enzymes to break up the material. Just like when a cell takes in molecules of food, the lysosomes break the food down into smaller and simpler products that the cell can use. If the lysosomes pick up a really bad intruder then they will eat it up and eject what is left of it out of the cell.