EVERYDAY SCIENCE

Detailed explanation-1: -Glycolysis, which is the first step in all types of cellular respiration is anaerobic and does not require oxygen. If oxygen is present, the pathway will continue on to the Krebs cycle and oxidative phosphorylation.

Detailed explanation-2: -The first stage of cellular respiration, called glycolysis, takes place in the cytoplasm. In this step, enzymes split a molecule of glucose into two molecules of pyruvate, which releases energy that is transferred to ATP.

Detailed explanation-3: -Glycolysis can take place without oxygen in a process called fermentation. The other three stages of cellular respiration-pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation-require oxygen in order to occur.

Detailed explanation-4: -The Respiratory System The body needs oxygen for energy. It gets this oxygen from the air around you. When you breathe in through your nose or mouth, you pull air into your throat and down the windpipe.

Detailed explanation-5: -Answer and Explanation: If oxygen is not present, glycolysis still proceeds but instead of oxidative phosphorylation, the electron carriers are regenerated through lactic acid fermentation. Our cells prefer to do aerobic respiration because it makes more ATP per glucose molecule.