a) Cystic fibrosis affects ion transport in what type of cells? (1 mark)
Cystic fibrosis affects ion transport in epithelial cells
b) The CFTR protein regulates the transport of a number of ions; name 2 of these ions. (2 marks)
The CFTR protein regulates the transport of Cl- and Na+
c) Explain why a defective CFTR gene could cause Dan to produce very salty sweat. (5 marks)
The normal function of the CFTR gene provides instructions for making a protein channel called the cystic fibrosis transmembrane. This protein channel transports chloride ions across the semipermeable membrane of cells that produce mucus, tears, sweat, saliva, and digestive enzymes. Due to osmosis, water will pass through the membrane from low concentrations of chloride, to high concentrations. Controlling the movement of water in tissues is necessary for the production of thin, free flowing mucus. …show more content…
This impairs the transport of chloride ions and the movement of water in and out of cells. In the sweat glands of patients with cystic fibrosis, the protein channel blocks chloride from being reabsorbed into the cells. The prevention of reabsorption causes an excess of chloride to be excreted out of the skin thus producing very salty sweat.
d) What is the main diagnostic test for cystic fibrosis? What was the result in Dan’s case? (2 marks)
The main diagnostic test for cystic fibrosis is the sweat test that tests the amount of Cl- levels. This is collected on a pad or paper and then analysed. Dan did not share his sweat test results, as he was unsure of them although he did mention that his sweat was very salty and he sweated more than normal when
Cystic fibrosis affects ion transport in epithelial cells
b) The CFTR protein regulates the transport of a number of ions; name 2 of these ions. (2 marks)
The CFTR protein regulates the transport of Cl- and Na+
c) Explain why a defective CFTR gene could cause Dan to produce very salty sweat. (5 marks)
The normal function of the CFTR gene provides instructions for making a protein channel called the cystic fibrosis transmembrane. This protein channel transports chloride ions across the semipermeable membrane of cells that produce mucus, tears, sweat, saliva, and digestive enzymes. Due to osmosis, water will pass through the membrane from low concentrations of chloride, to high concentrations. Controlling the movement of water in tissues is necessary for the production of thin, free flowing mucus. …show more content…
This impairs the transport of chloride ions and the movement of water in and out of cells. In the sweat glands of patients with cystic fibrosis, the protein channel blocks chloride from being reabsorbed into the cells. The prevention of reabsorption causes an excess of chloride to be excreted out of the skin thus producing very salty sweat.
d) What is the main diagnostic test for cystic fibrosis? What was the result in Dan’s case? (2 marks)
The main diagnostic test for cystic fibrosis is the sweat test that tests the amount of Cl- levels. This is collected on a pad or paper and then analysed. Dan did not share his sweat test results, as he was unsure of them although he did mention that his sweat was very salty and he sweated more than normal when