Cellular Transport essays

Cellular Transport essays The transport of materials through cellular membranes is a crucial function for the survival of cells. There are three different methods of transport through which materials can pass through cellular membranes: active transport, passive transport, and facilitated or carrier mediated transport. In our lab experiment, we studied the active transport of the amino acid leucine into the bacterium Escherichia coli and the passive transport of water molecules into onion cells. In the first experiment, we attempt to substantiate the hypothesis that active transport of leucine in E-coli would only occur when cells are supplied with glucose since glucose enable the production of ATP (adenosine triphosphate). ATP supply the energy needed for active transport. Leucine is a radioactive aminoacid. Radioactive materials have been able to make biochemical assays less complex and improve the ability for biological researches to follow biochemical reactions in cells. One of the most important uses of radioisotopes is the ability for these isotopes to act as radioactive tracers. These tracers function as a tool for the study of metabolic and transport processes. The presence of a radioisotope does not change the chemical properties of a molecule. Since, they are able to emit detected particles, radioactive molecules can be traced in cells and cellular extracts. All radioactive isotopes have three properties: (1) they generally emit alpha or beta particles o r gamma rays or combination. (2) Half-lives (which are the time it takes for half of the radioactive material to decay) are used to measure the rate of radioactive decay. (3) The radioactive decay energy which measures the kinetic energy with which the particles are emitted (Bilington 7). In the lab, the radioactive tracer molecule, C14, was used in order to follow the path of the amino acid, leucine, in Escherichia coli ( a bacterium). This experiment In the passive transpo...