Gluconeogenesis. Pentose phosphate pathway. Fructose and galactose metabolism

1. Choose the one in correct answer. The key gluconeogenic enzymes are….:

A. phosphoglucomutase;

B. pyruvate carboxylase;

C. phosphoenolpyruvate carboxy kinase;

D. fructose-1,6-bisphosphatase;

E. glucose-6-phosphatase.

2. Choose the one in correct answer. The substrates for gluconeogenesis are...:

A. pyruvic acid and lactate;

B. malate and oxaloacetate;

C. glycogenic amino acids and glycerol;

D. glycerol and fatty acids;

E. phosphoenol pyruvate and pyruvate.

3. Which one of the following statements about gluconeogenesis is in correct?

A. Only liver can replenish blood glucose through gluconeogenesis, because glucose-6-phosphatase is present mainly in liver;

B. Glucose-6-phosphatase is active in liver and present in kidney and intestinal mucosa cells;

C. Glucose-6-phosphatase is active in muscle and present in kidney and intestinal mucosa cells;

D. Gluconeogenesis maintains the blood glucose level during starvation;

E. 6 ATP are required to generate one glucose molecule;

4. Key enzymes of gluconeogenesis are activated by ….. Choose the one in correct answer.

A. glucagon;

B. insulin;

C. adrenalin;

D. cortisol;

E. acetyl-CoA.

5.The rate- limited reaction of the pentose-phosphate pathway of glucose is catalyzed by…. Choose the correct answer:

A. hexo-kinase;

B. glucose-6-phosphate dehydrogenase;

C. gluconolactone hydrolase;

D.6-phospho-gluconate dehydrogenase;

E.isomerase.

6. Key enzymes of the pentose-phosphate pathway (PPP) of glucose is activated by ….. Choose the one correct answer.

A. glucagon;

B. insulin;

C. adrenalin;

D. cortisol;

E. acetyl-CoA.

7.Cofactor of transketolase is derivative from vitamin…. Choose the one correct answer.

A. thiamine;

B. riboflavin;

C. niacin;

D. pyridoxine;

E. folic acid.

8. PPP is operating in following organs…. Choose the one in correct answer.

A. liver;

B. adipose tissue and lens;

C. muscle;

D. adrenal cortex, testes and ovaries;

E. mammary glands, erythrocytes, macrophages.

9. Which one of the following statements concerning hereditary fructose intolerance is in correct?

A. it is the autosomal recessive inborn error of metabolism. This is seen when sucrose is introduced in the diet of infants (usually around 6 months of age);

B. vomiting and loss of appetite are seen. Hepatomegaly and jaundice may occur.

C. the defect is in aldolase;

D. accumulation of fructose-1-phosphate will inhibit glycogen phosphorylase. This leads to accumulation of glycogen in liver and hypoglycemia. If liver damage progresses, death will occur;

E.withdrawal of fructose from the diet will not relieve the symptoms.

10. Which one of the clinical features of galactosemia is in correct?

A. hypoglycemia;

B. hyperglycemia;

C. hepatomegaly and jaundice;

D. mental retardation and congenital cataract;

E. galactosemia and galactosuria.