What is the distance '$a$' in the given figure (in $pm$)?

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

The blood concentration of glucose in a normal healthy individual is:

In which one of the following is nitrogen not a constituent?

$P$: Lake or sea water does not freeze completely.
$Q$: The latent heat of water is very high.

Identify and list $10$ interesting small molecular weight biomolecules. Determine if there are industries that manufacture these compounds through isolation and identify their primary buyers.