Which is the most abundant macromolecule in the cytoplasm?

Which of the following is a monomer of protein?

Match List-$I$ and List-$II$ with respect to proteins and their functions and select the correct option.

List-$I$	List-$II$
$1$. Collagen	$p$. Fights infectious agents
$2$. Trypsin	$q$. Hormone
$3$. Insulin	$r$. Enzyme
$4$. Antibody	$s$. Intercellular ground substance

Nitrogen is an essential component of .......

The "Ramachandran plot" is used to confirm the structure of:

Which properties do amino acids exhibit in solution by acting as electrolytes through their $-COOH$ and $-NH_2$ groups?