Practical lesson 2 glycolysis: reaction, regulation, energy balance. Aerobic oxidation of glucose

Choose the correct answer:

1. Name the location of glycolysis enzymes in the cell:

1. Mitochondrion;

2. Nucleus;

3. Cytosol;

4. Lysosomes;

5. Microsomes;

2.The key enzymes of glycolysis, catalyzing irreversible reactions are….

A. hexokinase, phosphofructokinase, pyruvate kinase;

B. phosphohexose isomerase, glyceraldedehyde-3-phosphate dehydrogenase; aldolase;

C. phosphotriose isomerase, phosphoglycerate mutase, enolase;

D. enolase, pyruvate kinase, lactate dehydrogenase;

E. hexokinase, phosphohexose isomerase, phosphofructokinase.

3.The number of ATP synthesizing during the glycolysis are…

A.1;

B.2;

C.3;

D.4;

E.0.

4.The end product converting glucose by anaerobic glycolysis is….:

A.pyruvic acid;

B.lactate;

C. acetyl CoA;

D.CO₂ and H₂O;

E.glycogen.

5.The end product converting glucose by aerobic glycolysis is….:

A.pyruvic acid;

B.lactate;

C. acetyl CoA;

D.CO₂ and H₂O;

E.glycogen.

6. Enzyme catalyzing forming NADH during glycolysis is…..:

A. hexokinase;

B. phosphofructokinase;

C. pyruvate kinase;

D. phosphohexose isomerase;

E. glyceraldehyde-3-phosphate dehydrogenase.

7. Which one of the following statements concerning the glycolysis is correct?

A. The conversion of glucose to lactate requires the present of oxygen;

B. Hexokinase is important in hepatic glucose metabolism only in the absorptive period following consumption of the carbohydrate- containing meal;

C. Fructose 2,6-bisphosphate is a potent inhibitor of phosphofructokinase;

D. The rate-limiting reactions are also the irreversible reactions;

E. The conversion of glucose to lactate yields two ATP and 2 NADH.

8.The reaction catalyzed by phosphofructokinase:

A.is activated by high concentration of ATP and citrate;

B. uses fructose-1-phosphate as substrate;

C. is the regulated reaction of the glycolytic pathway;

D. is near equilibrium in most tissues;

E. is inhibited by fructose 2,6- bisphosphate.

9.Compared with the resting stage, vigorously contracting muscle shows;

A.an increased conversion of pyruvate to lactate;

B. decreased oxidation of pyruvate to CO₂ to water;

C. a decreased NADH/NAD⁺ ratio;

D. a decreased concentration of AMP;

E. decreased levels of fructose 2.6-bisphosphate.

10.A 34-year-old man presented with symptoms of weakness, fatigue, shortness of breath, and dizziness. His hemoglobin levels were between 5 to 7 g/dl (normal for a male being greater than 13.5 g/dl). Red blood cells isolated from the patient showed abnormally low level of lactate production. A deficiency of which one of the following enzymes would be the most likely cause of this patient’s anemia.

A. Phosphoglucose isomerase;

B. Phosphofructokinase;

C. Pyruvate kinase;

D. Hexokinase;

E. Lactate dehydrogenase.

Practical lesson 3 gluconeogenesis. Pentose phosphate pathway. Fructose and galactose metabolism

1. Choose the one incorrect 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 incorrect 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 incorrect?

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 incorrect 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 incorrect 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 incorrect?

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 incorrect?

A. hypoglycemia;

B. hyperglycemia;

C. hepatomegaly and jaundice;

D. mental retardation and congenital cataract;

E. galactosemia and galactosuria.