5.1.5 Animal Responses

Question 1

different sources of ATP used in muscle contraction during strenuous exercise

Answer 1

sources of ATP: free ATP in muscle cells/sarcoplasm, ATP formed from creatine phosphate or phosphocreatine, runs out quickly
aerobic respiration: occurs when O2 is present, oxidative phosphorylation, greater yield of ATP, delivery of O2 to tissues does not meet demand, O2 is limited in strenuous exercise
anaerobic respiration: needed during strenuous exercise, only involves glycolysis, ATP formed by substrate-level phosphorylation, net yield of 2 ATP per glucose, smaller yield of ATP, NAD regenerated so glycolysis can continue, cannot continue indefinitely due to accumulation of lactic acid