AP BIOLOGY

Detailed explanation-1: -If oxygen is not present glucose is partially broken into pyruvate. This process is called anaerobic respiration. In the absence of oxygen, glucose is not completely oxidized into water and carbon-di-oxide. If oxygen is completely absent, then fermentation occurs.

Detailed explanation-2: -Anaerobic respiration is a normal part of cellular respiration. Glycolysis, which is the first step in all types of cellular respiration is anaerobic and does not require oxygen.

Detailed explanation-3: -Anaerobic respiration usually occurs in lower plants and microorganisms. In the absence of oxygen, the glucose derived from food is broken down into alcohol and carbon dioxide along with the production of energy.

Detailed explanation-4: -This process of breaking down glucose in the absence of oxygen is aptly named anaerobic glycolysis.[1] Additionally, cells that do not contain mitochondria (e.g., erythrocytes) cannot perform oxidative phosphorylation.