Question

The Venn diagram compares aerobic and anaerobic respiration.

Answer 1

The right answer is A. uses pyruvic acid

Pyruvate, the final product of glycolysis, follows different catabolic pathways according to the nature of the organism and the metabolic conditions.

- Lactic fermentation: anaerobic glycolysis in the muscle in contraction or in certain tissue types (brain, retina, erythrocytes).

- Alcoholic fermentation: anaerobic glycolysis in yeast and certain microorganisms.

- The oxidative decarboxylation followed by the Krebs cycle: oxidation of pyruvate to CO2 and H2O in animals, plants and many prokaryotic aerobic cells.

Answer 2

Ans.

Aerobic respiration involves complete breakdown of a glucose molecule in the presence of oxygen to generate energy, in the form of ATP molecules (36 molecules of ATP).

On the other hand, anaerobic respiration involves partial breakdown of a glucose molecule in the absence of oxygen to generate energy as ATP molecules (2 molecules of ATP).

The common feature, shared by both  aerobic and anaerobic respiration is use of pyruvate (pyruvic acid). The pyruvic acid is formed by the process of glycolysis, which is common for both the processes.  

In aerobic respiration, pyruvic acid is used to form acetyl coenzyme A that enters the Kreb's cycle, while during the anaerobic respiration, pyruvic acid is used to make alcohol or lactic acid to regenerate NAD+.

Thus, the correct answer is option A). 'uses pyruvic acid.'