Guiding Questions - carbohydrate metabolism PDF

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Guiding Questions: Carbohydrate Metabolism

Pages numbers (Lehninger 7e) refer to key concept areas.

Multiple Choice Questions 1. Page: 553Which of the following statements is not true concerning glycolysis in anaerobic muscle? A) B) C) D) E)

Fructose 1,6-bisphosphatase is one of the enzymes of the pathway. It is an endergonic process. It results in net synthesis of ATP. It results in synthesis of NADH. Its rate is slowed by a high [ATP]/[ADP] ratio.

2. Page: 565The metabolic function of the pentose phosphate pathway is to: A) B) C) D) E)

act as a source of ADP biosynthesis. generate NADPH and pentoses for the biosynthesis of fatty acids and nucleic acids. participate in oxidation-reduction reactions during the formation of H2O. provide intermediates for the citric acid cycle. synthesize phosphorus pentoxide.

3. Page: 606Glycogen is converted to monosaccharide units by:

A) B) C) D) E)

glucokinase. glucose-6-phosphatase glycogen phosphorylase. glycogen synthase. glycogenase.

4. Page: 534Which of the following reactions in glycolysis produces ATP as a product? A) B) C) D) E)

Hexokinase Glyceraldehyde-3-phosphate dehydrogenase Pyruvate kinase Aldolase Phosphofructokinase-1

5. Page: 619Which combination of cofactors is involved in the conversion of pyruvate to acetyl-CoA? A) B) C) D) E)

Biotin, FAD, and TPP Biotin, NAD+, and FAD NAD+, biotin, and TPP Pyridoxal phosphate, FAD, and lipoic acid TPP, lipoic acid, and NAD+

6. Page: 558-

Gluconeogenesis must use “bypass reactions” to circumvent three reactions in the glycolytic pathway that are highly exergonic and essentially irreversible. Reactions carried out by which three of the enzymes listed must be bypassed in the gluconeogenic pathway? 1) 2) 3) 4) 5)

Hexokinase Phosphoglycerate kinase Phosphofructokinase-1 Pyruvate kinase Triosephosphate isomerase

A) B) C) D) E)

1, 2, 3 1, 2, 4 1, 4, 5 1, 3, 4 2, 3, 4

Short Answer Questions 7. Pages: 601Outline the release of glucose from hepatocytes into the circulation. 8. Pages: 539Explain the regulation of PFK1 & PFK2. 9. Pages: 408Describe the nature and role of the glucose transporters found in human cells. 10. Pages: 589Compare and contrast regulation of carbohydrate metabolism in liver, muscle and tumor cells....