Question

Calculate the number of ATPs generated from one saturated 14-carbon fatty acid. For this question, assume that each NADH molecule generates 2.5 ATPs and that each FADH2 molecule generates 1.5 ATPs.

Answer 1

A total of 36 ATPs are produced from the complete oxidation of a 14-carbon fatty acid. The calculation involves accounting for ATPs generated from 6 cycles of β-oxidation, additional ATPs from the last acetyl-CoA molecule, minus the activation cost.

Step-by-step explanation:

ATP Yield from the Oxidation of a 14-Carbon Saturated Fatty Acid

To calculate the number of ATPs generated from one saturated 14-carbon fatty acid, we can use the provided information about fatty acid oxidation. Fatty acid oxidation comprises repetitive cycles, with the exception of the last cycle, and the ATP yield for each cycle can be determined based on the energy currency molecules produced: FADH₂, NADH, and acetyl-CoA.

First, we need to determine the number of cycles for a 14-carbon fatty acid, which is ½n - 1 or 7 - 1, equating to 6 cycles. During each cycle, one molecule of FADH₂ and NADH are produced, which are equivalent to 1.5 ATPs and 2.5 ATPs, respectively. This gives us 6 cycles × (1 FADH₂ + 1 NADH) × their respective ATP values, plus an additional 10 ATPs from the last acetyl-CoA, followed by a subtraction of 2 ATPs for activation. As we are asked to ignore any mention of palmitic acid, we will continue with the calculation for our specific case—the 14-C fatty acid.

• For the 14-C fatty acid:
  (6 cycles × (1.5 ATP + 2.5 ATP)) + 10 ATP - 2 ATP (activation cost) = (6 × 4) + 10 - 2 = 36 ATPs.

In the end, a total of 36 ATPs are produced from the complete oxidation of a saturated 14-carbon fatty acid, when accounting for the ATPs generated from the oxidation of FADH₂ and NADH in the electron transport chain (ETC) plus the acetyl-CoA entering the citric acid cycle.

Answer 2

A total of 36 ATPs are produced from the complete oxidation of a 14-carbon fatty acid. The calculation involves accounting for ATPs generated from 6 cycles of β-oxidation, additional ATPs from the last acetyl-CoA molecule, minus the activation cost.

Step-by-step explanation:

ATP Yield from the Oxidation of a 14-Carbon Saturated Fatty Acid

To calculate the number of ATPs generated from one saturated 14-carbon fatty acid, we can use the provided information about fatty acid oxidation. Fatty acid oxidation comprises repetitive cycles, with the exception of the last cycle, and the ATP yield for each cycle can be determined based on the energy currency molecules produced: FADH₂, NADH, and acetyl-CoA.

First, we need to determine the number of cycles for a 14-carbon fatty acid, which is ½n - 1 or 7 - 1, equating to 6 cycles. During each cycle, one molecule of FADH₂ and NADH are produced, which are equivalent to 1.5 ATPs and 2.5 ATPs, respectively. This gives us 6 cycles × (1 FADH₂ + 1 NADH) × their respective ATP values, plus an additional 10 ATPs from the last acetyl-CoA, followed by a subtraction of 2 ATPs for activation. As we are asked to ignore any mention of palmitic acid, we will continue with the calculation for our specific case—the 14-C fatty acid.

• For the 14-C fatty acid:
  (6 cycles × (1.5 ATP + 2.5 ATP)) + 10 ATP - 2 ATP (activation cost) = (6 × 4) + 10 - 2 = 36 ATPs.

In the end, a total of 36 ATPs are produced from the complete oxidation of a saturated 14-carbon fatty acid, when accounting for the ATPs generated from the oxidation of FADH₂ and NADH in the electron transport chain (ETC) plus the acetyl-CoA entering the citric acid cycle.

Answer 3

The total ATP yield from the complete oxidation of one saturated 14-carbon fatty acid, considering β-oxidation cycles, the citric acid cycle, and the electron transport chain, is calculated to be 82 ATPs.

Step-by-step explanation:

To calculate the number of ATPs generated from one saturated 14-carbon fatty acid, we need to consider the products of fatty acid oxidation and their ATP yields. The process involves the activation of the fatty acid, followed by multiple β-oxidation cycles, and then the oxidation of acetyl-CoA via the citric acid cycle and electron transport chain (ETC).

For a 14-carbon fatty acid, there are ((0.5 × 14 - 1) × 14) ATPs produced from the β-oxidation cycles, minus 2 ATP for activation, plus an additional 10 ATP for the last acetyl-CoA. Therefore, we compute the ATP yield as follows:

((0.5 × 14 - 1) × 14) + 10 - 2 = 82 ATPs.

The activation of the fatty acid costs 2 ATPs, which is converted to AMP and two inorganic phosphates (2P₁). Each cycle of β-oxidation gives us one FADH₂ and one NADH, which yield 1.5 and 2.5 ATPs respectively, plus an acetyl-CoA which ultimately yields approximately 10 ATPs when oxidized in the TCA cycle. This formula accounts for the 0.5 × number of carbons in the fatty acid, minus 1 because the last cycle yields two acetyl-CoA, making the net ATP gain higher.