The bond between two amino acids shown to the right is a/an
· Peptide bond.
· Hydrogen bond.
· Phosphodiester bond.
· Glycosidic bond.
· Ester bond.
The Correct Answer and Explanation is:
Correct Answer: Peptide bond.
Explanation
The bond formed between two amino acids is called a peptide bond. This type of bond is a covalent chemical bond that links the carboxyl group of one amino acid to the amino group of another. The formation of a peptide bond is a dehydration synthesis reaction (also known as a condensation reaction), where a molecule of water (H₂O) is removed as the bond forms.
In more detail, the carboxyl group (–COOH) of one amino acid reacts with the amino group (–NH₂) of the next. During this reaction, the –OH from the carboxyl group and an –H from the amino group combine and are released as water. The resulting bond –CO–NH– is the peptide bond.
Peptide bonds are fundamental in biology because they form the backbone of proteins. Proteins are made up of one or more long chains of amino acids, also called polypeptides. The sequence and chemical properties of these amino acids determine the protein’s structure and function. The formation and breaking of peptide bonds are crucial for protein synthesis and degradation, respectively.
Let’s briefly clarify why the other options are incorrect:
- Hydrogen bond: This is a weak interaction, not a covalent bond, and it typically occurs between polar molecules or regions (e.g., between water molecules or parts of protein structures).
- Phosphodiester bond: Found in nucleic acids like DNA and RNA, linking the phosphate group of one nucleotide to the sugar of another.
- Glycosidic bond: A bond between two monosaccharides (sugar molecules) in carbohydrates.
- Ester bond: Formed between a carboxylic acid and an alcohol, commonly seen in fats and oils, not in proteins.
In conclusion, the specific bond that links two amino acids during protein formation is the peptide bond.
