Question

Describe the flow of energy from a glucose molecule to ATP during respiration, and compare this to the flow of energy from glucose to acids and alcohols during fermentation. Specifically, what carries the energy from glucose to ATP - what energy conversions must occur during the process. Compare the ATP production during respiration with ATP production during fermentation.

Answer 1

Glycolysis is the first step of the cellular respiration in an organism which is metabolic pathway that is completed in the cytosol of the cell that leads to the converting glucose to the pyruvate in order to produce energy in form of ATP:

1. Glucose-6-phosphate is ---> fructose-6-phosphate

2. fructose-6-phosphate ---> fructose-1,6-biphosphate

3. fructose-1,6-biphosphate ---> glyceraldehyde-3-phosphate(GAP) and dihydroxyacetone phosphate (DHAP).

4. GAP is oxidised ----> 3-bisphosphoglycerate + NADH

5. 3-bisphosphoglycerate ----> 1,3-bisphophoglycerat

6. 1,3-bisphophoglycerate ----> 3-phosphoglycerate

7. 3-phosphoglycerate ----> 2-phosphoglycerate

8. 2-phosphoglycerate ----> phosphoenolpyruvate (PEP)

9. phosphoenolpyruvate to ADP ----> pyruvic acid + ATP

Formation of ATP occurs in both pathways or process that are respiration and fermentation. Fermentation is a catabolic pathway leads to the degradation of sugars (partial) that result in the gain of energy and this energy are absorbed in ATP. There are difference of the amount of energy or ATP produce in these process in respiration 38 ATP are produced whereas during fermentation only 2 ATP are produced.