1. The cell membrane structure is vital to the life of the cell. The cell membrane is shaped as having a phosphate head at the very outer surface, and two fatty acid tails hanging from it. The membrane is double, so at the tip of the fatty acid tails, there are two more fatty acid tails attached to another phosphate head. This is what it looks like: The reason the cell membrane is shaped like this is mainly to control the water flow in and out of the cell. Water is very important to the cell: if too much water...
interesting. The allosteric site of enzyme #1 is shaped like the end product, and when there is a high concentration of the end product, it binds with the allosteric site of enzyme #1, changing the shape of the active site of enzyme #1. Thus, reactant #1 can no longer bind with enzyme #1, effectively shutting down the entire process. When the cell needs more end-product, it removes the end-product from the allosteric site of enzyme #1, and reactant #1 can bind with enzyme #1 to form reactant #2, and so on. Thus, the biochemical pathway is back in business.