$A$ chemical substance acts as the currency of energy metabolism in a cell. It is:

Which of the following structures represents a ribonucleoside?

Identify the substances among the following that contain both glycosidic and peptide bonds in their structure.

Assertion $(S)$: The measure of disorder in a biological system is called free energy.
Reason $(R)$: The energy available in a biological system to perform work is called entropy.
$(A)$ Both $S$ and $R$ are true,and $R$ is the correct explanation of $S$.
$(B)$ Both $S$ and $R$ are true,but $R$ is not the correct explanation of $S$.
$(C)$ $S$ is true and $R$ is false.
$(D)$ $S$ is false and $R$ is true.
$(E)$ Both $S$ and $R$ are false.

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

Which vitamin contains $N$?