• Describe the energy sources available to skeletal muscle and the role of ATP in contraction

Creatine phosphate - provides rapid ATP at the onset of muscle contraction

glycolysis - anaerobic fast rate of atp generation from glucose/glycogen for 1min

oxidative phosphorylation - aerobic suplies most amount of ATP per glucose molecule

• Describe events during cross bridge formation to generate sarcomere shortening

ATP binds to a low energy state myosin head, the ATP is then hydrolised into ADP and Pi this changes the myosin head into a high energy state/position and the myosin head has a greater affinity for the actin, the myosin head then binds with the actin and the adp and pi are released, this causes the myosin head to contract and return to its original low energy state, in doing this it pulls down the actin filaments and causes contraction of the sarcomere, ATP will again bind to the myosin head and cause the myosin head to detach from the actin filament causing the sarcomere to return to its normal state again until another action potential initiates calcium release.

• List the different types of skeletal muscle fibre and compare & contrast their main biochemical and physiological properties

• Define the length-tension relationship and load-velocity relationship of muscle contraction