Cell Membrane Transport

Cell Membrane Transport

ZOOL 2011.09

October 11, 2013

A. Introduction:

Cells are the most significant building blocks of all living things. They are also the tiniest living organisms in the human body which provides structure for the body and intake nutrients that become energy. Cell membranes control what goes in and out the cell, it protects it. The lipid bilayer describes the membrane of both animal and plant cells where the properties that make up phospholipids are very important to the cell membrane function, it has protein which is dispersed properly and it mainly functions in the selective transport of molecules both in and out of the cell. Just like transport of many molecules and water are very vital processes for many living organisms. There is active and passive transport; active transport includes functions of a cell membrane to selectively push specific types of molecules across the membrane and there is passive transport in which it does not have need of an active role for the membrane. Osmosis and dialysis are also occasionally called passive transports because they too do not require an active role for the membrane. Osmosis is movement of water across a semipermeable membrane of low concentration to a solution of high concentration. On the other hand diffusion is movement of molecules from a high concentration to a low concentration. Osmosis is a form of diffusion but a distinction would be that it deals essentially with water. Tonicity is what makes the cells either shrink or grow depending on the environment it is placed at, it is an osmotic pressure and it is influenced by the different concentrations of solutes in and out of the cell. Filtration is what is used to remove solid particles and they can be removed by passing through a liquid and gas.

The information above is very important because it is exactly what everything in this lab will be about. It explains in detail what every single little definition and important information means. It is relevant to what the lab is trying to describe and the human body needs it in order to function the way it supposed to. Osmosis helps by the cells not dying, if a cell has too much water osmosis will occur and will withdraw some of it to keep it from overflowing and vice versa if it's hypertonic it will move some water in to keep it from shriveling up. Filtration helps the body by filtering blood vessels and refunding clean blood into the body and exerting harmful substances in water and later on urine.

There are five experiments that are going to be tested which are Experiment one, two, three, four and five. Experiment one deals with osmosis and biochemical testing, the independent variable for osmosis will be the tonicity and