What is the percentage of water in living cells?

Energy released by the hydrolysis of one molecule of $ATP$ is (in $kcal$)

$X$ - Glycosidic bond is formed by dehydration.
$Y$ - Due to hydrolases,peptide bond splits.

Cut surfaces of fruit and vegetables often become dark because

$ATP$ stands for:

Assertion $A$: Living organisms obtain various molecules and elements from their environment.
Reason $R$: Living organisms synthesize components essential for their body.
Which option is correct for Assertion $A$ and Reason $R$?