PHSI 208 Lecture Notes - Lecture 3: Reduced Properties, Mhc Class I, Myosin
Document Summary
What must occur for muscle to return to a relaxed state: answer: myosin will unbind from actin, which requires an input of an atp molecule. Also the calcium needs to come out of the muscle and will be pumped back into the sarcoplasmic reticulum. Atp is also broken down in order to pump that calcium back into the sarcoplasmic reticulum. Atpase enzyme is found in at least two locations in the muscle fiber: the head of the myosin (to contract the muscle, the sarcoplasmic reticulum membrane (energy to bring the calcium back to the sarcoplasmic reticulum) Which fibre type has the highest myosin atpase activity: type i, type iia, type iix. Which fibre type has the highest sarcoplasmic reticulum atpase activity: type i, type iia, type iix (because even though they have a fast myosin activity they also have a fast and high recovering)