What is the function of proteins in a living cell?

Match the names of biomolecules listed under column $I$ with the characteristics given under column $II$; choose the answer which gives the correct combination of the alphabets of the two columns.

Column-$I$ (Biomolecule)	Column-$II$ (Characteristics)
$(A)$ $ATP$	$(p)$ One or more sugar monomers
$(B)$ $DNA$	$(q)$ The main source of energy
$(C)$ Protein	$(r)$ Two strands of nucleotides
$(D)$ Carbohydrate	$(s)$ Long sequence of amino acids

Which substance is most abundant in a cell?

Which of the following components obtained from mushrooms is $NOT$ considered an organic compound?

The common immediate source of energy in cellular activity or the energy currency of the cell is:

Vitamin $B_{12}$ is also known as: