Cell Membrane essays

Cell Membrane essays Cell Membrane/ Electron Transport Chain Biochemical Pathway 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 enters the cell, the cell will explode, and if too much water leaves the cell, the cell will shrivel up and die. This is how the cell membrane controls water flow: the phosphate heads are polar, and slightly attract water. However, the fatty acid tails in between are non polar, and repel water, so the fatty acid tails prevent too much water from entering or leaving the cell. With this tough membrane, there has to be a way for things to enter the cell. This is where the channel proteins come in. They act as gateways to the cell. There are many ways to enter the cell. Some ways require energy, while others dont. The ways that require energy are put into a category called active transport, while the ways that dont require energy are put into a category called passive transport. An example of active transp! ort is the proton pump. The proton pump is an integral part of chemiosmosis, and it pumps protons from an area of low concentration to an area of high concentration. This requires energy since things like to move from an area of high concentration to an area of low concentration. An example of passive transport is facilitated diffusion. This is very easy since the particle is moving from an area of high concentration to an area of low concentration and through a channel protein made exactly for its size and shape. 2. These membranes are very importan...