Draw the form of l-tryptophan which is present at biological ph.

The structure of tryptophan at PH 7 is provided as an attachment. Please open to see it.

Explanation:

Tryptophan is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a non-polar aromatic amino acid. It is essential in humans, meaning the body cannot synthesize it; it must be obtained from the diet. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin and vitamin B3. It is encoded by the codon UGG.

The structure of tryptophan at PH 7 is provided as an attachment. Please open to see it.

c is the answer because when something is left after something evaporates that shows the chemical change.