Energy is accumulated in $ATP$ in which of the following?

Which of the following vitamins contains an isoprene unit?

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

In the structure of nucleic acids,in which of the following forms is phosphoric acid incorporated?

The energy released by one molecule of $ATP$ is approximately: (in $kcal$)

The figure given below shows three velocity-substrate concentration curves for an enzyme reaction. What do the curves $a, b$ and $c$ depict respectively?