EVERYDAY SCIENCE

Detailed explanation-1: -When an organism is in a low oxygen situation, such as running sprints, cellular respiration ceases and the organism must use a different metabolic pathway for creating energy without oxygen. What do we call this process? During the Krebs cycle, pyruvic acid molecules are broken down to harvest 2 ATPs.

Detailed explanation-2: -Respiration rate decreased as oxygen tension decreased and approached zero at low oxygen tensions. This result was independent of cell density.

Detailed explanation-3: -In prolonged activities where intensity is low, the body will use fat as a main energy source and spare the use of muscle glycogen and blood glucose so that it is available for use if exercise intensity increases and oxygen availability is decreased.

Detailed explanation-4: -Answer and Explanation: When animal cells do not get enough oxygen to satisfy the requirements for cellular respiration, cells may continue to produce ATP from glucose because D) they perform lactic acid fermentation to produce 2 ATP from glucose instead of about 30 ATP that cellular respiration produces.

Detailed explanation-5: -Anaerobic Respiration occurs when there is a lack of oxygen. This process still breaks down the pyruvates but does not make as much ATP as aerobic respiration. In plants, anaerobic respiration is called alcohol fermentation and in animals, anaerobic respiration is called lactic acid fermentation.