Oxidative decarboxylation of piruvic acid. Krebs cycle

8 9 10 11 12 13 14

Choose the correct answer:

1. The central metabolic pathway is…..

A. the metabolic pathway characterized converting glucose to pyruvate;

B. the metabolic pathway characterized converting amino acids to pyruvate;

C. the metabolic pathway characterized converting fat acids to pyruvate;

D. the metabolic pathway characterized converting pyruvate or acetyl CoA to end products;

E. the metabolic pathway characterized converting fat acids to acetyl CoA

2. The Pyruvate Dehydrogenase Complex (PDC) consists of following cofactors… Choose the in correct answer:

A. thiamine pyrophosphate;

B. Co-enzyme A;

C. FAD and NAD⁺;

D. lipoamide;

E. FMN and NADP⁺

3. Which one of the following statements concerning the PDC is in correct?

A. it is located inside the mitochondria;

B. it converts pyruvate to acetyl CoA;

C. it consists of 3 enzymes;

D. the dephosphorylated form of the pyruvate dehydrogenase is active;

E. NADH and acetyl CoA activate PDC.

4. The PDC is activated by….. Choose the in correct answer.

A. pyruvate dehydrogenase phosphatase;

B. pyruvate dehydrogenase kinase;

C. pyruvate;

D. Mg²⁺;

E. AMP

5. The PDC is inhibited by….. Choose the in correct answer.

A. pyruvate dehydrogenase phosphatase;

B. pyruvate dehydrogenase kinase;

C. NADH;

D. acetyl CoA;

E. ATP

6. Which one of the following statements about citric acid cycle is in correct?

A. it is the final common oxidative pathway where acetyl CoA oxidized to CO₂;

B. it is the source of reduced coenzymes;

C. it provides precursors for synthesis of amino acids and nucleotides;

D. it is located inside the mitochondria;

E. it is located in the cytosol.

7. Acetyl CoA is used to biosynthesis….. Choose the in correct answer.

A. fatty acids;

B. bile acids;

C. cholesterols;

D. proline;

E. ketone bodies.

8 In the Krebs cycle …… NADH molecules are generated.

A. 0

B. 1

C. 2

D. 3

E. 4

9. In the Krebs cycle …… CO₂ molecules are liberated.

A. 0

B. 1

C. 2

D. 3

E. 4

10.In the Krebs cycle …… FADH₂ molecule is generated.

A. 0

B. 1

C. 2

D. 3

E. 4

III. KEYS

PRACTICAL LESSON 1

GENERAL METABOLISM. INTERMEDIARY METABOLISM

1.A.

2.C.

3.D.

4.A.

5.B.

6.A.

7.C.

8.D.

9.D.

10.D

PRACTICAL LESSON 2

BIOLOGICAL OXIDATION. ELECTRON TRANSPORT CHAIN. BOENERGETICS AND OXYDATIVE PHOSPHORILATION

1. B.

2. D. Thirteen of the approximately 100 polypeptides required for oxidative phosphorylation are coded for by mitochondrial DNA, including the electron transport components cytochrome c and coenzyme Q. Oxygen directly oxidizes cytochrome oxidase. Malat dehydrogenase directly reduces FAD. Cyanide inhibits electron flow, proton pumping and ATP synthesis.

3.D

4.D.

5.E.

6.D

7.B

8.E

9.E

10.C

PRACTICAL LESSON 3

FREE RADICALS AND ANTI-OXIDANTS. VITAMINS AS ANTIOXIDANTS

1. B

2. C