Dr. Albee
Cell Biology Section 11
18 September 2016
1. Describe the structure of CFTR. You must provide a written description for full credit. A picture on its own is not enough. A picture with a description is acceptable. (5 points)
When cystic fibrosis transmembrane conductance regulator CTFR channels are functioning normally, they allow chloride ions to move outside of the cell. When the CTFR is mutated the chloride ions are unable to leave out of the cell channel which causes a thick coat of mucus lining the outside of the cell. Cystic Fibrosis is caused by mutations in the CTFR gene. The CTFR gene is composed of 1480 amino acids and is found in the cell membrane. CTFR has two membrane domains. Each domain has a cytoplasmic …show more content…
The only function ATP has in the CTFR is that it is used as a ligand to open up the gate. CTFR structurally looks like an ABC-type transporter, but it is an ion channel that doesn’t actually use ATP. When CTFR is working in its normal conditions, it is a wild type protein ion transporter. This is the healthy version of the protein. The CTFR allows anions to flow down their chemical gradient. As a non-mutated gene, the CTFR regulates the movement of salt across the cell membrane through the gated channels. The normal functioning cell keeps passageways to the lungs and pancreas clear, however when the CTFR is not there, the cell will not allow the movement of sodium chloride. This salt builds up causes mucus build up inside and outside of the cell. As more mucus builds up, the mucus eventually ends up blocking important passageways to the lungs and pancreas causing infections and weakening the …show more content…
Epithelium cells are cells that line the body’s organs and when they are improperly functioning, this can lead to problems with the organs. Normal epithelial cells mucus that protects the body’s tissues. The epithelial cells in cystic fibrosis patients don’t produce viscous mucus like they should, so the thick mucus produced clogs both the airways and the intestinal track. Patients who do not have CF have properly functioning CTFR chloride channels that allow chloride ions to leave the cell, and water to follow via osmosis. This way there in a chloride balance inside and outside of the cell, and the mucus is watery and acts as a lubricant. In CF patients, these channel do not function and chloride ions build up inside of the cell. These chloride ions are then not followed by water, and the mucus becomes very concentrated and sticky. The sodium inside of the cell keeps the water with it because the water always follows the sodium ion. These proteins for the diffusion of salt into the airways are prohibited and since there is less water in the airways, the mucus builds up and becomes very sticky, leading to