Which of the following is the structure of glycerol?

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

How much energy is released by the hydrolysis of a single $ATP$ molecule under standard conditions (in $kcal$)?

Which of the following is a purine type of nitrogenous base?

Which of the following substances is found in fruit juices?

Which of the following structures represents ribose sugar?