Consider the following protein chain:

How many amino acids make the atoms in a planar unit? Why are the units planar?

Find the number of ways four different amino acids can be arranged so that each peptide formed is distinct from the others.

True or False: The chains of alternating peptide bonds and α-carbon atoms are the 'backbone' of a protein.

Enkephalin is a peptide responsible for regulating pain sensation in the body. There are two forms of enkephalin. One is met-enkephalin, which contains methionine and has the following primary structure: Tyr-Gly-Gly-Phe-Met. Provide the complete structural formula of met-enkephalin.

One or more essential amino acids are frequently lacking in seeds and vegetables. Based on the given table, indicate if the following combination provides all of the essential amino acids:

blackbeans and rice

Which of the following represents the condensed structural formula for the tripeptide Val-Tyr-Glu?