4. List and briefly discuss the 5 components of cellular membranes. 1. Phospholipids layer- 2 layers , polar and non polar , polar facing the extracellular fluid and cytoplasm 2. Transmembrane proteins-integral membrane proteins are proteins that expand the membrane 3. Interior protein network-peripheral proteins are in the interior side of the membrane 4. Cell surface markers are glycolipids, carbohydrates/lipid residues 5. Cholesterol helps maintain the membrane fluidity, they are between the phospholipids if the temperature drop it helps the membrane not to solidify
5. How did the advent of electron microscopy revolutionize cell biology? Provide very specific examples. The transmission electron microscope allows seeing the membrane structure and everything through the cell, with tremendous detail. The microtone is a specialized type of knife to cut the solidified cell, the cell fractures through the weak point; the hydrophobic non-polar side of the phospholipids bilayer. With this technique it gets the membrane proteins revealed.
8. Where in the phospholipid bilayer is the path of least resistance? (Important to understanding membrane structure) In the hydrophobic non-polar side of the membrane it is the weak point
10. A cell membrane is an incredibly fragile structure. However, it is maintained for the life of the cell. Briefly discuss exactly how a phospholipid is held together. The hydrogen bonding of water holds the 2 layers together, the phosphate group facing up and the fatty acids in the inside.
13. What happens when a cell membrane is “too fluid” or “too solid”? It lose its function that why we need cholesterol
14. What function does cholesterol have in membrane structure? (Moderate vs. low temperatures) It maintains the fluidity of the cell membrane; they wedge...