Condensed structural formulas of glycine and serine Glycine Serine 2. Condensed structural formulas of dipeptides Glycylserine Seryiglycine 3. Condensed structural formulas of the reactants and products for the hydroly- sis of serylglycine 4. Condensed structural formula for the tripeptide
The Correct Answer and Explanation is :
1. Condensed Structural Formulas of Glycine and Serine
- Glycine (Gly):
Condensed Structural Formula: NH₂CH₂COOH
Glycine is the simplest amino acid, consisting of a single hydrogen atom as its side chain. - Serine (Ser):
Condensed Structural Formula: NH₂CH(CH₂OH)COOH
Serine contains a hydroxymethyl group (-CH₂OH) attached to its central carbon atom.
2. Condensed Structural Formulas of Dipeptides
- Glycylserine:
Condensed Structural Formula: NH₂CH₂CO-NHCH(CH₂OH)COOH
This dipeptide is formed when the amino group of glycine reacts with the carboxyl group of serine. - Serylglycine:
Condensed Structural Formula: NH₂CH(CH₂OH)CO-NHCH₂COOH
This dipeptide is formed when the amino group of serine reacts with the carboxyl group of glycine.
3. Condensed Structural Formulas of the Reactants and Products for the Hydrolysis of Serylglycine
- Reactants:
Serylglycine: NH₂CH(CH₂OH)CO-NHCH₂COOH
Water: H₂O - Products:
Serine: NH₂CH(CH₂OH)COOH
Glycine: NH₂CH₂COOH
Hydrolysis of serylglycine involves breaking the peptide bond between serine and glycine by the addition of water, yielding free serine and glycine.
4. Condensed Structural Formula for a Tripeptide
- A tripeptide consists of three amino acids joined by peptide bonds. One example could be glutamine-glycine-alanine:
Condensed Structural Formula: NH₂CH₂CO-NHCH₂CO-NHCH₃COOH
This formula represents the tripeptide formed by the amino acids glutamine, glycine, and alanine.
Explanation:
A peptide is formed through a dehydration synthesis reaction between the amino group of one amino acid and the carboxyl group of another. In the case of dipeptides like glycylserine or serylglycine, two amino acids are connected by a peptide bond (-CO-NH-). The hydrolysis of peptides breaks the peptide bond by adding water, resulting in individual amino acids. Tripeptides contain three amino acids linked in the same manner.
Each amino acid has a central carbon (α-carbon) attached to an amino group (-NH₂), a carboxyl group (-COOH), and a side chain (R group) specific to each amino acid. The side chains in glycine and serine, for example, contribute to their unique properties. The formation and breakdown of peptides are essential for biological processes such as protein synthesis and digestion.