EVERYDAY SCIENCE

Detailed explanation-1: -It is also carried out by your muscle cells when you work them hard and fast. This is how the muscles of the sprinter in Figure 5.10.

Detailed explanation-2: -Your muscles are forced to work without enough oxygen. In these situations, your working muscles generate ATP anaerobically (i.e., without oxygen) using a process called fermentation. Fermentation is beneficial in that it can generate ATP quickly for working muscle cells when oxygen is scarce.

Detailed explanation-3: -In muscle cells, fermentation occurs through the lactic acid pathway. During this process, glucose is phosphorylated, broken down and oxidised to make two molecules of pyruvate. The produced pyruvate is then reduced by NADH to make lactic acid. Only two ATP molecules are produced using this pathway.

Detailed explanation-4: -Creatine Phosphate (with oxygen) So all muscle cells contain a high-energy compound called creatine phosphate which is broken down to make more ATP quickly. Creatine phosphate can supply the energy needs of a working muscle at a very high rate, but only for about 8–10 seconds.

Detailed explanation-5: -Anaerobic Glycolysis This process releases energy very rapidly. Glucose, or blood sugar, and stored carbs in the form of glycogen in your muscle cells are broken down through a series of steps to form a compound called pyruvate. This process yields two to three molecules of ATP for each molecule of glucose.