Biochemistry
Molecular Mechanisms In Inherited Disorders
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of VI pages
1. Mutation in what proteins results in Cystic Fibrosis?
Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)
2. What is CFTR?
membrane protein that acts as a chloride channel
3. CFTR belongs to what group of transporters?
group of ATP Binding Cassette (ABC) transporter
4. Describe the structure (domains) of CFTR?
It has 2 membrane spanning domains, two ATP binding domains and a regulatory domain that can be
5. What causes activation of CFTR?
phosphorylation of regulatory domain by PKA
6. Why is there low Na and H20 in the lumen (mucous)?
the mutant CPTR cant transport Cl from the cell into the lumen therefore Na will stay in cell to balance Cls
7. Why is the mucous thick and viscid in pts w/ Cystic Fibrosis?
due to the low water and electrolyte concentration in the mucous.
8. Why do CF pts have a higher risk of developing respiratory infections?
The thick viscid mucus are prone to developing bacterial infections.
9. Respiratory infections are common causes of what in CF pts?
mortality and morbidity
10. How does the mutant CFTR effect the pancreas?
Leads to thick pancreatic secretions which obstruct pancreatic duct and destroy tissue. Results in deficiency of
11. What type of tissues replace pancreatic tissue in pts with cystic fibrosis?
Fibrotic tissue and fat
12. What symptoms are found in pts with CF?
Malabsorption, sterility, salty sweat, chronic pancreatitis, secondary biliary cirrhosis and recurring resp
13. Why is there defective protein digestion in pts with CF?
Blockage of pancreatic duct results in deficient secretion of pancreatic enzymes like lipase, trypsin, and
14. Why is there steatorrhea in pts w/ CF?
B/C of the maldigestion of nutrients and the excretion of fat in stool due to deficiency of fat soluble vitamins
15. Why do many children w/ CF have protein malnutrition and delay in growth?
B/C of the deficient secretion of pancreatic enzymes which aid in the digestion of proteins
16. How is it possible to restore normal digestion and nutrition in pts w/ CF?
by providing pancreatic enzyme supplements
Biochemistry 2024/25 Edition
Molecular Mechanisms In Inherited Disorders
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of VI pages
1. Mutation in what proteins results in Cystic Fibrosis?
Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)
2. What is CFTR?
membrane protein that acts as a chloride channel
3. CFTR belongs to what group of transporters?
group of ATP Binding Cassette (ABC) transporter
4. Describe the structure (domains) of CFTR?
It has 2 membrane spanning domains, two ATP binding domains and a regulatory domain that can be
5. What causes activation of CFTR?
phosphorylation of regulatory domain by PKA
6. Why is there low Na and H20 in the lumen (mucous)?
the mutant CPTR cant transport Cl from the cell into the lumen therefore Na will stay in cell to balance Cls
7. Why is the mucous thick and viscid in pts w/ Cystic Fibrosis?
due to the low water and electrolyte concentration in the mucous.
8. Why do CF pts have a higher risk of developing respiratory infections?
The thick viscid mucus are prone to developing bacterial infections.
9. Respiratory infections are common causes of what in CF pts?
mortality and morbidity
10. How does the mutant CFTR effect the pancreas?
Leads to thick pancreatic secretions which obstruct pancreatic duct and destroy tissue. Results in deficiency of
11. What type of tissues replace pancreatic tissue in pts with cystic fibrosis?
Fibrotic tissue and fat
12. What symptoms are found in pts with CF?
Malabsorption, sterility, salty sweat, chronic pancreatitis, secondary biliary cirrhosis and recurring resp
13. Why is there defective protein digestion in pts with CF?
Blockage of pancreatic duct results in deficient secretion of pancreatic enzymes like lipase, trypsin, and
14. Why is there steatorrhea in pts w/ CF?
B/C of the maldigestion of nutrients and the excretion of fat in stool due to deficiency of fat soluble vitamins
15. Why do many children w/ CF have protein malnutrition and delay in growth?
B/C of the deficient secretion of pancreatic enzymes which aid in the digestion of proteins
16. How is it possible to restore normal digestion and nutrition in pts w/ CF?
by providing pancreatic enzyme supplements
Biochemistry 2024/25 Edition
