B. Protistans, a group thought to have given rise to other eukaryotic cells
The correct answers are:
2) Peptide bonds form from nucleophilic attack by an electron pair on an alpha - amino nitrogen atom on an alpha - carboxyl carbon atom of another amino acid and
4) Peptides are polymers of amino acids.
A peptide bond is an amide type of covalent chemical bond. It is formed between two amino acids: C1 (carbon end) of one alpha-amino acid and N2 (nitrogen end) of another. Peptide bonds are the basis for the formation of a peptide chain and consequently protein. Formation of peptide bond is a condensation process, meaning that when two amino acids combine and link, water molecule is released and dipeptide is a product of that reaction.
