Answer:
The correct answer is a an amino group and a carboxyl group.
Step-by-step explanation:
Alanine and serine are both amino acids.Alanine is a simple amino acids where serine is a hydroxyl amino acids.
When alanine and serine molecules combine to form a single molecule at that time an amino group and the carboxyl group will be joined together to form a ala-ser peptide linkage.