Energy is Needed for Muscle
Contraction
• ATP is the only source of energy used directly for muscle contractile
activities
• It supplies the energy for cross bridge movement, detachment and
operation of the calcium pump in the sarcoplasmic reticulum (SR)
• Only limited stores of ATP are immediately available in muscle tissues,
enough to power the first few seconds of exercise.
However, three pathways supply additional ATP as needed during
muscle contraction:
1. Creatine Phosphate
2. Oxidative phosphorylation
3. Glycolysis
, 2. Oxidative phosphorylation (OP)
• The multistep Oxidative phosphorylation pathway produces a rich yield of
ATP molecules for each glucose molecule processed.
• This pathway fueled by glucose and fatty acids.
• A relatively slow rate when compared to other pathways.
• It take place within the muscle mitochondria if sufficient O2 is present.
• During light exercise (walking) to moderate exercise (jogging or
swimming), muscle cells can form enough ATP through OP.
Contraction
• ATP is the only source of energy used directly for muscle contractile
activities
• It supplies the energy for cross bridge movement, detachment and
operation of the calcium pump in the sarcoplasmic reticulum (SR)
• Only limited stores of ATP are immediately available in muscle tissues,
enough to power the first few seconds of exercise.
However, three pathways supply additional ATP as needed during
muscle contraction:
1. Creatine Phosphate
2. Oxidative phosphorylation
3. Glycolysis
, 2. Oxidative phosphorylation (OP)
• The multistep Oxidative phosphorylation pathway produces a rich yield of
ATP molecules for each glucose molecule processed.
• This pathway fueled by glucose and fatty acids.
• A relatively slow rate when compared to other pathways.
• It take place within the muscle mitochondria if sufficient O2 is present.
• During light exercise (walking) to moderate exercise (jogging or
swimming), muscle cells can form enough ATP through OP.
