Which is the most abundant macromolecule in the cytoplasm?

$A$: Amino acids are amphoteric in nature.
$R$: Amino acids act as electrolytes in solution.

$A$: Tertiary structure of protein is absolutely necessary for many biological activities of proteins.
$R$: In protein,only right-handed helices are observed.

Select the correct option for the following matches:

$(1)$ Contractile protein	$(a)$ Immunoglobulin
$(2)$ Protein produced by cells	$(b)$ Globular protein
$(3)$ Protein that gives color to the iris	$(c)$ Actin
$(4)$ Protein for muscular movement	$(d)$ Melanin

Match the following columns correctly.

Column $I$	Column $II$
$(a)$ Actin	$(i)$ Transport of respiratory gases
$(b)$ Immunoglobulin	$(ii)$ Immunity
$(c)$ Melanin	$(iii)$ Pigmentation of the body
$(d)$ Hemoglobin	$(iv)$ Muscle movement

The given amino acid is . . . . . . in nature.