Myoglobin, and iron- and oxygen-binding protein found in the muscle tissue of vertebrates, is 0.316% fe by mass. if a myoglobin molecule contains one iron atom, what is the molar mass of myoglobin?

Myoglobin is a small, red protein that is found in muscles. It binds oxygen molecules and supplies them when the muscle is working.

The atomic weight  of Iron is 55,847 g/mol

This  problem tell us is 0.316% fe by mass and contains one iron atom

55.847 g/mol is to 0.316% as x is to 100%

x = 17673.10 g/mol

The molar mass of myoglobin is 17673.10 g/mol

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d