Lipogenesis

How does insulin affect the activity of the three glycolytic enzymes?

• Insulin increase their activity

• Insulin decrease their activity

• Insulin does not have any effect on glycolytic enzymes

How is Acetyl-CoA moved to the cytosol?

• Co-A is removed first and acetyl group crosses the membrane by diffusion

• Acetyl-CoA is converted to citrate which can cross the mitochondrial membrane

• Acetyl-CoA does not need to be transported to the cytosol

Where does lipogenesis occur in the cell?

• Cell membrane

• Mitochondria

• Cytosol

Which molecule blocks the activity of Carnitine acyl transferase I (CAT I) and why?

• Acetyl-CoA blocks CAT I to increase its entry into the mitochondria

• Malonyl-CoA blocks CAT I to block the breakdown of fatty acids

• Acetyl-CoA blocks the activity of PDHC to decrease the production of CAT I

How is the activity of the following enzymes affected in excessive beta-oxidation?

1. Pyruvate decarboxylase (PC)

2. PEP carboxykinase (PEPCK)

3. Pyruvate dehydrogenase complex

4. Isocitratae dehydrogenase

• 1. Increase

  2. decrease

  3. decrease

  4. increase

• 1. decrease

  2. Increase

  3. increase

  4. Increase

• 1. increase

  2. increase

  3. decrease

  4. decrease

How does insulin affect glycogenesis?

• Glycogenesis is increased

• Glycogenesis is decreased

Which is the rate limiting enzyme in the synthesis of fatty acids?

• Acetyl-CoA carboxylase (ACC)

• Acetyl-CoA synthase

• Acetyl-CoA decarboxylase

What is the difference between chylomicrons and VLDL?

• Chylomicrons contain fatty acids derived from diet and VLDL are endogenous fatty acids produced by the liver

• VLDLs contain fatty acids derived from diet and chylomicrons are endogenous fatty acids produced by the liver