Explain the process of breakdown of glucose in a cell 1 in the presence of oxygen and 2 in the absence of oxygen and 3 in lack of oxygen
Answers
Answer:
presence of oxygen is respiration
absence is glycolysis
lack is lactic acid fermentation and alcoholic dehyration
Answer:
i. In the presence of oxygen : In all the pathways, the first step in break down of glucose, a six -carbon molecule, into a three-carbon molecule, called pyruvate. This process occurs in the cytoplasm of the cell. In aerobic respiration breakdown of , pyruvate using oxygen takes place in mitochondria. It breaks up the three-carbon pyruvate molecule to give three molecules of carbon dioxide, water and lots of energy as compared to anaerobic respiration.
ii. In the absence of oxygen: In the absence of oxygen pyruvate may be converted into ethanol and carbon dioxide which is referred to as fermentation that takes place in yeast. Sometimes anaerobic respiration also occurs in our muscle cells, when there is lack of oxygen, i.e., during vigorous muscular activities. At that time pyruvate is converted into lactic acid which is also a three-carbon molecule. This build-up of lactic acid in our muscles causes fatigue or muscular cramps.