Exercise and metabolism Flashcards
(20 cards)
Anaerobic energy pathways
ATP>ADP+pi
Pcr+ADP>ATP+Cr
gylcolysis
Aerobic energy pathways
krebs cycle
oxidative phosphorylation
where do the anaerobic energy pathways occur vs the aerobic ones
cytoplasm v mitochondria
Stages of muscle contraction
ATP-bound myosin binds actin
ATP hydrolysis>slide
detach
new ATP binds>recovery
Why does a particular energy system/macromolecule fuel different forms of exercise?
it is the rate at which ATP can be resynthesised to fuel the rate of muscle contraction
limited by the substrate
How long does the ATP system power exercise for?
1-2s
phosphagen system and exercise
powers 10-15s exercise
instantaneous
highest rate of ATP resynthesis
Glycolysis and exercise
powers 3-5mins exercise
2nd fastest max rate of ATP resynthesis
which enzyme breaks down phosphocreatine
creatine kinase
which enzyme converts pyruvate to acetyl coa
pyruvate dehydrogenase
citric acid cycle summary
acetyl portion of acetyl coa combines with oxaloacetate to form citrate catalysed by citrate synthase
cirate>isocitrate>alpha ketoglutarate>succinyl coa>succinate>fumarate>malate>oxaloacetate
per molecule of glucose what is the net gain of ATP
30-34
what type of respiration occurs with high intensity short exercise
anaerobic
faster depletion of ATP than with endurance
energy supply changes during sprinting as time increases
pcr decreases
glycolysis increases
muscle lactate increases
what foods is creatine found in
meat fish poultry
body synthesises creatine from non essential amino acids
where is 95% of body creatine stores
muscle
effects of intracellular acidification due to carbs
reduces sensitivity of contractile apparatus to calcium ions
how does bicarbonate supplementation improve performance?
neutralises excess stomach acid in indigestion
enters muscle cells which increases extracellular pH
H+ leaving muscle cells neutralised
side effect of bicarbonate supplementation
carbon dioxide produced
gastrointestinal distress
why is glycogen relied on more than fat at higher exercise intensities?
broken down quicker
less oxygen dependent
produces more energy per unit of oxygen consumed
