Why are globular proteins important? what are their primary functions and what are they made of?

They can act as enzymes, transporters of other molecules through membrane and haemoglobin which carries oxygen in the red blood cell.
 some globular proteins are made of polypeptides e.g. haemoglobin which is made if 2 β-polypeptide chains and 2 α-polypeptide chains.

Globular proteins are considered important because they are the significant components of enzymes, hormones and antibodies. They are made up of long chains of twisted and folded amino acids. Their primary function as an enzyme is through catalyzing organic reactions and also, they function as messengers which transmits messages to regulate biological processes.

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature