2015-08-13
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PRACTICAL LESSON 1
CARBOHYDRATES: BIOLOGICAL FUNCTIONS AND CLASSIFICATION. METABOLIC PATHWAY OF CARBOHYDRATES
GLYCOGEN METABOLISM
1.E.
2.A.
3.C.
4.E.
5.E.
6.C.
7.C.
8.D.
9.E.
10.C
PRACTICAL LESSON 2
GLYCOLYSIS: REACTION, REGULATION, ENERGY BALANCE. AEROBIC OXIDATION OF GLUCOSE
1. C.
2. A.
3.D
4.B.
5.D.
6.E
7.D. Hexokinase, phosphofructokinase and pyruvate kinase are all irreversible and are the regulated steps in glycolysis. The conversion of glucose to lactate (anaerobic glycolysis) is a process that does not involve a net oxidation or reduction and, thus, oxygen is not required. Glucokinase (not hexokinase) is important in hepatic glucose metabolism only in the absorptive period following consumption of a carbohydrate-containing meal. Fructose 2.6-bisphosphate is a potent activator (not inhibitor) of phosphofructokinase. The conversion of glucose to lactate yields two ATP but no net production of NADH.
8.C. Phosphofructokinase is the pace-setting enzyme of glycolysis. It is inhibited by ATP and citrate, uses fructose 6-phosphate as substrate, and catalyzes a reaction that is far from equilibrium. The reaction is activated by fructose 2.6-bisphosphate.
9.A. Vigorously contracting muscle shows an increased formation of lactate and an increased rate of pyruvate oxidation compared with resting skeletal muscle. The levels of AMP and NADH increase, whereas change in the concentration of fructose 2.6-bisphosphate is not a key regulatory factor in muscle.
10.C. Decreased lactate production in the erythrocyte indicates a defect in glycolysis. Among patients exhibition genetic defects of glycolytic enzymes, about 95% show a deficiency in pyruvate kinase, and 4% exhibit phosphoglucose isomerase deficiency.
Pyruvate kinase deficiency is the second most common cause (after glucose 6-phosphate dehydrogenase deficiency) of enzyme deficiency-related hemolytic anemia.
PRACTICAL LESSON 3
GLUCONEOGENESIS. PENTOSE PHOSPHATE PATHWAY. FRUCTOSE AND GALACTOSE METABOLISM
1. A
2. D
3.C
4.B
5.B
6.B
7.A
8.C
9. E
10. B
QUESTIONS FOR TEST CONTROL MODULE 4
PRACTICAL LESSON 1
