Question

Answer the following:

a. Cellular respiration is a vital energy management process for all organisms. Contrast aerobic and anaerobic respiration with fermentation. Distinguish all of these processes with regard to ATP yield and the identity of final electron acceptor molecule.

b. Fermentation is employed by humans for production of a variety of materials – discuss the how the end products of fermentation make this possible using the fermentation carried out by the yeast, Saccharomyces cerevisiae, in bread making, as an example.

Answer 1

Answer a

Aerobic respiration occurs in the presence of oxygen,Complete breakdown of organic food take place, Waste product are co2 and h2o

anaerobic respiration occurs in the absence of oxygen , release small amount of energy,produce co2 and ethanol as a waste product.

without using the Kreb Cycle or the Electron Transport Chain a catabolic process releases energy from glucose which does not require oxygen; as the final electron acceptor we use an organic molecule and that produces end products such as ethanol or lactic acid. ATP is only generated during Glycolysis. Most important function is to regenerate NAD+ so that Glycolysis can continue.

Aerobic respiration begins with glycolysis. In which glucose gets broken down and, forms a molecule called pyruvate after losing some electrons If there is a sufficient supply of oxygen, or sometimes other types of electron acceptors, because pyruvate goes on another level of aerobic respiration. The process of glycolysis will produce net gain of 2 ATP.

Answer b

Saccharomyces cerevisiae, also known as bakers yeast which prefer fermentation over aerobic respiration. yeast to make the bread “rise” by producing bubbles of carbon dioxide gas. Ethanol is also produced as a byproduct. The alcohol content of bread varies with the kind of yeast used, the time it sets, and the temperature of baking