Which one of the following is a peptide hormone?

Insulin production and its action in the human body are responsible for regulating blood sugar levels. To which of the following categories does this compound belong?

The enzyme which converts maltose to glucose is:

The enzyme which hydrolyses triglycerides to fatty acids and glycerol is called

Which of the following enzymes is not useful in the digestion of proteins?

$Testosterone$ is responsible for the development of secondary male characteristics like deep voice and facial hair.