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

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.