Q.18.95 - An Introduction to General, Organic, and Biological Chemistry

Question

Match the following ATP yields to reactions a to g 

1.5 ATP  2.5 ATP  7 ATP  50 ATP 12 ATP  32 ATP  36 ATP

a. Glucose forms two pyruvate

b. Pyruvate from acetyl CoA

c. Glucose from two acetyl CoA

d. Acetyl CoA goes to one turn of the citric acid cycle

e. Caproic acid is completely oxidized.

f. NADH + H⁺ is oxidized to NAD⁺

g. FADH₂ is oxidized to FAD. 

Step-by-Step Solution

Answer

a. glucose molecules yield two pyruvates = 7 ATP

b. Pyruvate to Acetyl CoA= 2.5 ATP

c. Glucose yields two acetyls CoA's=12 ATP

d. Acetyl CoA goes through one turn of the Citric acid cycle=  10 ATP

e. Caproic acid is completely oxidized = 36 ATP.

f. NADH + H⁺ is oxidized to NAD = 2.5 molecule of ATP

g. FADH₂ is oxidized FAD= 1.5 molecules of ATP.

Step 1: Part (a) Given information

To determine ATP molecules in Glucose form two pyruvates.

Step 2: Part (a) Explanation

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

Thus, glucose molecules yield two pyruvates = 7 ATP 

Step 1: Part (b) Given information

To determine ATP molecules in Pyruvate from acetyl CoA.

Step 2: Part (b) Explanation

• NADH₂ and FADH₂ donate electrons to the electron transport chain.  
• NADH₂ molecule donates electrons to complex I and is reduced to NAD⁺. 
• FADH₂ donates electrons to complex II and is reduced to FAD⁺. 
• Based on the P/O ratio, 1 NADH₂ form 2.5 ATP, and 1 FADH₂ forms 1.5 ATP via ETC.

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

When two acetyl CoA are produced from 1 glucose, there are 7 ATP from glycolysis and 5 ATP from 2 pyruvate conversion to acetyl CoA.

Total ATP from glucose to pyruvate = $7 \mathrm{ATP} + 2 \times 2.5 \mathrm{ATP}= 12 \mathrm{ATP}$

Step 1: Part (c) Given information

To determine ATP molecules in Glucose from two acetyl CoA 

Step 2: Part (c) Explanation

When two acetyl CoA are produced from 1 glucose, there are 7 ATP from glycolysis and 5 ATP from 2 pyruvate conversion to acetyl CoA.

Total ATP from glucose to pyruvate = $7 \mathrm{ATP} + 2 \times 2.5 \mathrm{ATP}= 12 \mathrm{ATP}$.

Step 1: Part (d) Given information

To determine ATP molecules in Acetyl CoA goes to one turn of the citric acid cycle.

Step 2: Part (d) Explanation

When 1 acetyl CoA is broken down to 2 CO₂ during the citric acid cycle, there is a production of 3 NADH₂, 1 FADH_2, and 1 ATP.

Total ATP in the breakdown of acetyl CoA= $3 \times 2.5\mathrm{ATP} + 1 \times 1.5 \mathrm{ATP} + 1 \mathrm{ATP}= 10 \mathrm{ATP}.$

Step 1: Part (e) Given information

To determine ATP molecules when Caproic acid is completely oxidized. 

Step 2: Part (e) Explanation

Caproic acid is a C₆ fatty acid. Hence, it undergoes 2 rounds of $\mathrm{\beta }$ oxidation to produce 3 acetyl CoA, 2 FADH_2, and 2 NADH₂. Each acetyl CoA produces 10 ATP.

Thus,

Total ATP from caproic acid=  $3 \times 10 \mathrm{ATP} + 2 \times 1.5 \mathrm{ATP}+ 2 \times 2.5 \mathrm{ATP}= 38 \mathrm{ATP}$

However, 2 ATP are required for the transport of caproic acid into the mitochondria.

Total ATP from caproic acid= $38 \mathrm{ATP}-2 \mathrm{ATP}= 36 \mathrm{ATP}$.

Step 1: Part (f) Given information

To determine ATP molecules in NADH + H⁺ is oxidized to NAD⁺.

Step 2: Part (f) Explanation

• NADH₂ and FADH₂ donate electrons to the electron transport chain.  
• NADH₂ molecule donates electrons to complex I and is reduced to NAD⁺. 
• FADH₂ donates electrons to complex II and is reduced to FAD⁺. 
• Based on the P/O ratio, 1 NADH₂ form 2.5 ATP, and 1 FADH₂ forms 1.5 ATP via ETC.

Step 1: Part (g) Given information

To determine ATP molecules when FADH₂ is oxidized to FAD. 

Step 1: Part (g) Explanation

• NADH₂ and FADH₂ donate electrons to the electron transport chain.  
• NADH₂ molecule donates electrons to complex I and is reduced to NAD⁺. 
• FADH₂ donates electrons to complex II and is reduced to FAD⁺. 
• Based on the P/O ratio, 1 NADH₂ form 2.5 ATP, and 1 FADH₂ forms 1.5 ATP via ETC.