2.14- Cystic Fibrosis and the effects on cell membranes

Describe the role of the CFTR protein

Describe the role of the CFTR protein

Facilitates the diffusion of Cl ions across the cell membrane to adjust the viscosity of mucus

Explain how a faulty CFTR protein results in stickier and thicker mucus

A faulty CFTR protein with limit or prevent the diffusion of Cl ions into the mucus. This means not as much or no water will be transported into the mucus via osmosis as there is no concentration gradient from the Cl ions. This means the mucus will become more sticky and viscous overtime.

Explain the effects of CF on the respiratory system

The sticky and viscous mucus means it can’t be moved by the cilia. This means it builds up on the cells increasing the diffusion distance and decreasing the rate of diffusion.

Explain the effects of CF on the male reproductive system

Lack a sperm duct on both sides so the sperm can’t leave the testes. The vas deferens could also be partially blocked by the mucus which then lowers sperm count

Explain the effects of CF on the female reproductive system

A mucus plug can develop in the cervix. It can then stop sperm from reaching the egg.

Explain the effects of CF on the digestive system

Pancreatic duct blocked by mucus which impairs the release of enzymes. This reduces the rate of digestion so food is not fully digested and not all nutrients are fully absorbed. The causes energy to be lost which leads to malabsorption syndrome.

Enzymes get trapped behind the plug which damages the pancreas. Damaged cells then can’t produce insulin which causes diabetes.