Which respiratory protein helps the cardiac muscle to take in oxygen?
a. Myoglobin
b. Hemocyanin
c. Hemoglobin
d. Carbonic anhydrase
e. Oxyhemoglobin

Myoglobin

Explanation:

-Myoglobin is an oxygen-binding molecule found in muscles that is made of a single polypeptide with only one heme group

-Dissociation curve is to the left of the haemoglobin curve and does not display a sigmoidal shape (myoglobin cannot undergo cooperative binding)

-Myoglobin's affinity for oxygen is greater than haemoglobin and becomes saturated at low oxygen concentrations

-Under normal conditions (at rest) myoglobin is saturated with oxygen and will store it until O2 levels in the body drop with intense exercise

-This allows it to provide oxygen when levels are very low (e.g. in a respiring muscle) and so delays anaerobic respiration and lactic acid formation

d.

explanation: