Q. 18.56 - An Introduction to General, Organic, and Biological Chemistry

Question

What is the ATP energy yield associated with each of the following?

a. ${\mathrm{FADH}}_2\to \mathrm{FAD}$

b. $\mathrm{glucose} + {60}_2\to 6{\mathrm{CO}}_2+6{\mathrm{H}}_2\mathrm{O}$ 

c. $\mathrm{glucose} \to 2 \mathrm{lactate}$

d. $\mathrm{pyruvate}\to \mathrm{lactate}$

Step-by-Step Solution

Answer

(a) The two ATP energy is released during oxidation of FADH.

(b) The thirty two ATP energy is released during the given reaction i.e. $\mathrm{glucose} + {60}_2\to 6{\mathrm{CO}}_2+6{\mathrm{H}}_2\mathrm{O}$

(c) The two ATP energy is released during the given reaction i.e. $\mathrm{glucose} \to 2 \mathrm{lactate}$

(d) The two ATP energy is released during the given reaction i.e. $\mathrm{pyruvate}\to \mathrm{lactate}$

Part (a) Step 1: Given information

We need to find the yield of ATP in the given reaction i.e. ${\mathrm{FADH}}_2\to \mathrm{FAD}$

Part (a) Step 2: Explanation

We know that

The energy produced by FADH's oxidation when it reaches electron transport complex II is used to make two ATP. The  equation of ${\mathrm{FADH}}_2$  is

${\mathrm{FADH}}_2+\frac{1}{2}{\mathrm{O}}_2+2\mathrm{ADP}+2{\mathrm{P}}_{\mathrm{i}}\to \mathrm{FAD}+{\mathrm{H}}_2\mathrm{O}+2\mathrm{ATP}$

Part (b) Step 1: Given information

We need to find the yield of ATP in the given reaction i.e.  $\mathrm{glucose} + {60}_2\to 6{\mathrm{CO}}_2+6{\mathrm{H}}_2\mathrm{O}$

Part (b) Step 2: Explanation

We know that 

The given reaction is of the citric cycle and oxidation of one pyruvate produces six ATP and two cycles of citric acid produces twenty-four ATP 

Therefore, a total of thirty-two ATP are produced

Part (c) Step 1: Given information

We need to find the yield of ATP in the given reaction i.e. $\mathrm{glucose} \to 2 \mathrm{lactate}$

Part (c) Step 2: Explanation

We know that 

Under the anaerobic conditions, phosphorylate ADP is directly converted into ATP

Therefore, two ATP are produced from two ADP

Part (d) Step 1: Given information

We need to find the yield of ATP in the given reaction i.e. $\mathrm{pyruvate}\to \mathrm{lactate}$

Part (d) Step 2: Explanation

We know that 

Under anaerobic conditions, pyruvate is converted into lactate in the cytoplasm which in result produces two ATP molecules