24. Lipid Metabolism

Which one of the following coenzymes is not a part of the β-oxidation pathway?

How many total FADH₂, NADH, and acetyl CoA molecules will be produced when stearic acid undergoes β‑oxidation?

Tripalmitin is a TAG formed by the esterification of glycerol with three palmitic acid molecules. How many acetyl CoA molecules will be produced by the complete oxidation of tripalmitin? (Hint: consider glycerol metabolism too).

How many molecules of acetyl-CoA are produced by catabolism of the following fatty acids, and how many ß oxidations are needed?

a. Palmitic acid, CH₃(CH₂)₁₄COOH

Look back at the reactions of the citric acid cycle (Figure 21.8) and identify the three reactions in that cycle that are similar to the first three reactions of the ß oxidation of a fatty acid. <IMAGE>

Oxygen is not a reactant in the ß oxidation of fatty acids. Can ß oxidation occur under anaerobic conditions? Explain.

Why is the stepwise oxidation of fatty acids called ß oxidation?

Write the equation for the final step in the catabolism of any fatty acid with an even number of carbons.

How many molecules of acetyl-CoA result from catabolism of 1 molecule of glyceryl trilaurate?

(Hint: See Worked Example 24.3 and don’t forget glycerol.)

Identify each of the following reactions a to e in the β oxidation of palmitic acid, a C₁₆ fatty acid, as (18.7) (1) activation

(2) first oxidation

(3) hydration

(4) second oxidation

(5) cleavage

a. Palmitoyl CoA and FAD form α , β-unsaturated palmitoyl CoA and FADH₂

Identify each of the following reactions a to e in the β oxidation of palmitic acid, a C₁₆ fatty acid, as (18.7) (1) activation

(2) first oxidation

(3) hydration

(4) second oxidation

(5) cleavage

c. Palmitic acid, CoA, and ATP form palmitoyl CoA.

Consider the complete oxidation of arachidic acid, a saturated fatty acid, [20:0].

b. How many cycles of β oxidation occur?

Lauric acid, a saturated fatty acid, [12:0], is found in coconut oil.

e. How many cycles of β oxidation occur?

Capric acid is a saturated fatty acid, [10:0].

a. Draw fatty acyl capric acid activated for β oxidation.

Lauric acid, a saturated fatty acid, [12:0], is found in coconut oil.

a. Draw fatty acyl lauric acid activated for β oxidation.

The glycerol derived from lipolysis of triacylglycerols is converted into glyceraldehyde 3-phosphate, which then enters into step 6 of the glycolysis pathway. What further transformations are necessary to convert glyceraldehyde 3-phosphate into pyruvate?