During muscle contraction, ATP is provided by a. a coupled reaction of creatine phosphate with ADP, b. aerobic respiration of glucose, and c. anaerobic glycolysis. ______  (1) Which provides ATP fastest? ______  (2) Which does (do) not require that oxygen be available? ______  (3) Which provides the highest yield of ATP per glucose molecule? ______  (4) Which results in the formation of lactic acid? ______  (5) Which has carbon dioxide and water products? ______  (6) Which is most important in endurance sports?

Video transcript

Hi, everyone. Let's take a look at this practice problem together, which of the following processes occur when muscles work at a high intensity and cannot receive enough oxygen for aerobic respiration. The answer options are a anaerobic glycolysis. B oxidative phosphorylation, C beta oxidation and D citric acid cycle. So recall that during aerobic respiration, cells will break down glucose and produce energy. So the function of aerobic respiration is to produce energy and they do so by using oxygen. Now, without oxygen, another process takes over options. B through D are all part of aerobic respiration. And so we can automatically say that options B through D are all incorrect answers because they will all require oxygen in order for them to occur. But we already know A is the answer. But let's go ahead and review what e what each process does. Now oxidative phosphorylation, this occurs in mitochondria and remember it's the final step of aerobic respiration. Beta oxidation is the process of breaking down fatty acids in order to produce energy. Now recall that citric acid cycle is also known as the Krebs cycle. And this again requires oxygen and it helps to produce that chemical energy and again, is part of aerobic respiration. So, the correct answer is anaerobic glycolysis or anaerobic respiration. Now, this process can occur without oxygen. It is faster and you get quick energy from it during high intensity, but it's not as efficient and it produces lactic acid as a byproduct which can cause muscle soreness. So again, the correct answer is option, a anaerobic glycolysis. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.