Question

State if each of the following processes releases or acquires ATP.

a. citric acid cycle

b. glucose from two pyruvate

c. pyruvate from acetyl CoA

d. glucose from glucose-6-phosphate

e. oxidation of $\mathrm{\alpha }$-ketoglutarate

f. first six reactions of glycolysis

g. activation of a fatty acid

Short answer

a. 2 ATP molecules are released.

b. 2 ATP molecules are released.

c. 1 ATP molecule is released.

d. 1 ATP molecule is required.

e. No ATP molecule is required.

f. 2 ATP molecules are required.

g. 1 ATP molecule is required.

Step-by-step solution

Part (a) Given information

To determine ATP molecules in citric acid cycle

Part (a) Explanation

During the citric acid cycle, two ATP molecules are produced by substrate phosphorylation.

Part (b) Given information

To determine ATP molecules in glucose from two pyruvate

Part (b) Explanation

During glycolysis, glucose form two pyruvates, this process requires two ATP molecules producing 4 ATP and 2 NADH molecules.

Thus, as a result, 2 ATP molecules are produced.

Part (c) Given Information

To determine ATP molecules in pyruvate from acetyl CoA

Part (c) Explanation

During the formation of pyruvate from acetyl CoA, one ATP molecule is produced.

Part (d) Given information

To find ATP molecule in glucose from glucose-6-phosphate.

Part (d) Explanation

During the conversion of glucose to glucose-6-phosphate, one ATP molecule is required which is further converted into ADP.

Part (e) Given information

To find ATP molecules in the oxidation of $\mathrm{\alpha }$-ketoglutarate.

Part (e) Explanation

The oxidation of $\mathrm{\alpha }$-ketoglutarate, it produces succinyl CoA during the Kerb's cycle which produces NADH that is equivalent to 2.5 ATP, but there is no direct consumption of ATP molecules.

Part (f) Given information

To find ATP molecules in first six reactions of glycolysis

Part (f) Explanation

In the first six reactions of glycolysis, i.e. conversion of glucose to 1,3-phosphoglycerate. Two ATP molecules are consumed or required.

Part (g) Given information

To find ATP molecules in the activation of a fatty acid.

Part (g) explanation

During the activation of fatty acids, it requires one ATP molecule which is converted into AMP.

Thus, it is equivalent to the consumption of two ATP molecules.