BIO 3303 Lecture Notes - Lecture 17: Oxidative Phosphorylation, Atp Hydrolysis, Adipose Tissue
30 Aug 2016
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Document Summary
Muscle made up of myofibers of different fiber types: isoform switching can occur in response to physiological conditions (i. e. cyclist vs swimmer depending on need of muscle, exercise, temperature. If brain wants to turn on a particular type of muscle, then it"s easier to be selective one muscle fiber over another. Energy use by a muscle depends on: fibre type, length and intensity of activity, fuel reserves available. Atp needed in muscle contraction for: ca2+ cycling (ca2+-atpase = 25-30% of atp use, crossbridge cycle (myosin atpase) power and detachment, na+,k+-atpase (recovery from muscle ap) Atp hydrolysis: muscle atp stores are small, 5 mmol l-1 exhausted within about 10 twitches, can increase 20-fold to several hundred-fold with activity. In the muscle itself, the atp stores are very small very little freee atp (about 10 muscle twitches) need to replenish these stores. Atp required for muscle contraction and relaxation (cross-bridge cycling and atpase pumps) Last only a very short period (few seconds)
