Chapter 23, Problem 88A

Interpretation Introduction

Interpretation:

The total energy in kJ which is converted to ATP during the process of cellular respiration and fermentation should be calculated and compared.

Concept introduction:

A set of metabolic reactions which takes place in the organism cell to convert chemical energy from molecules of oxygen into ATP that is adenosine triphosphate is known as cellular respiration. In this process, glucose breaks down in the presence of oxygen and produces carbon dioxide with release of water and energy.

The chemical reaction is:

${\text{C}}_{\text{6}}{\text{H}}_{\text{12}}{\text{O}}_{\text{6}}{\text{+6O}}_{\text{2}}\to {\text{6CO}}_{\text{2}}{\text{+6H}}_{\text{2}}\text{O+energy}$

A metabolic process which results chemical changes in organic substrates by the action of enzymes is known as fermentation. It is also defined as the energy is extracted from the carbohydrates in the absence of oxygen. In this process, glucose breaks down in the absence of oxygen.

Answer to Problem 88A

Total energy converted to ATP during cellular respiration = 1159 kJ

Total energy converted to ATP during fermentation = 61 kJ

Energy converted to ATP during cellular respiration is more than energy converted to ATP during fermentation.

Explanation of Solution

In cellular respiration process, 1 mole of glucose results in the formation of 38 moles of ATP.

In fermentation process, 1 mole of glucose results in the formation of 2 moles of ATP.

Since, one mole of ATP = 30.5 kJ energy

Total energy in kJ which is converted to ATP during cellular respiration is calculated as:

Energy converted to ATP = $\text{1 mole glucose }\times \frac{38\text{ mole ATP}}{1\text{ mole glucose}}\times \frac{30.5\text{ kJ}}{1\text{ mole ATP}}$

= $1159\text{ kJ}$

Total energy in kJ which is converted to ATP during fermentation is calculated as:

Energy converted to ATP = $\text{1 mole glucose }\times \frac{2\text{ mole ATP}}{1\text{ mole glucose}}\times \frac{30.5\text{ kJ}}{1\text{ mole ATP}}$

= $61\text{ kJ}$

According to the above calculations, the energy converted into ATP during the process of cellular respiration is more than the energy converted into ATP during the process fermentation.