Lecture 3 Flashcards
What are the main ATP dependent processes in skeletal muscle?
Cross-bridge cycling Sarcolemmal Excitability (Na+/K= ATPase) Calcium pumping into the SR (SERCA - Ca2+ ATPase)
What is the result of measuring the concentration of a metabolite in dry muscle compared to wet muscle?
4 - 5 fold increase in concentration of metabolite when reported in dry muscle compared to wet muscle.
Why is it a bad idea to directly inject ATP into muscles?
ATP is a highly regulated variable and injecting ATP would shut down other pathways that produce ATP
What are the mechanisms of ATP generation?
Substrate level phosphorylation (anaerobic) Oxidative phosphorylation (aerobic)
What are some examples of anaerobic ATP production?
Phosphocreatine replenishes ATP in a reaction within an acid.
2ADP -> ATP + AMP
Glycogen + 3 ADP + 3Pi -> 2 Lac + H + 3ATP
What are the processes with the most ATP - generating power?
How is ATP generating power related to ATP generating capacity?
ATP-generating power is fastest in PCr and glycolysis. Processes that generate ATP very quickly tend to not be able to generate much ATP.
How is the lag in ATP generation by oxidative phosphorylation counteracted?
Lag in ATP generation by oxidative phosphorylation is counteracted by phosphocreatine.
Why is there a dependence on anaerobic metabolism in weightlifters?
When lifting weights it can cause blood supply occlusion resulting in lots of anaerobic metabolism.
How is oxygen uptake related to power output?
Oxygen uptake is linearly related to power output.
What stored energy do muscles have?
Muscles have a small amount of triglycerides and glycogen.
Which have more energy triglycerides or glycogen?
energy of triglyceride is twice as much as glycogen
How does exercise intensity influence which metabolites are used?
At low intensity exercise more fat is used for energy.
At high intensity more energy is obtained from glycogen and carbohydrates
How does exercise duration influence which metabolites are used?
Longer duration causes more reliance on fatty acids and plasma glucose rather than glycogen
What factors influence which metabolites are utilised more during exercise?
Exercise intensity and duration (main factor) Diet Training Temperature Age & Gender
