Question

Peptides are formed from (a) aliphatic amines (b) carbohydrates (c) \(\alpha\)-amino acids (d) aromatic amines

Short answer

Peptides are formed from (c) \(\alpha\)-amino acids.

Step-by-step solution

Identify Key Concept

First, identify what a peptide is. Peptides are short chains of amino acid monomers linked by peptide (amide) bonds. The building blocks of peptides are amino acids.

Know the Components

We know peptides are formed from b1-amino acids, which are amino acids having an amino group, a carboxylic acid group, and a specific side chain all attached to the same b1-carbon atom.

Analyze Each Option

Examine each given option: - (a) Aliphatic amines: These are simple organic compounds with at least one nitrogen atom and do not form peptides. - (b) Carbohydrates: These are sugars, not involved in peptide formation. - (c) b1-amino acids: These are the molecules that link to form peptides. - (d) Aromatic amines: These are organic compounds with an aromatic ring linked to an amino group, and they do not form peptides.

Select the Correct Answer

Based on the analysis, option (c) b1-amino acids is the correct component that forms peptides.

Key concepts

Alpha-Amino Acids

Alpha-amino acids are the building blocks of proteins and peptides, playing a fundamental role in biochemistry. These molecules are characterized by having an amino group (\(-NH_2\)) and a carboxylic acid group (\(-COOH\)) attached to the same central carbon atom, known as the alpha carbon. Additionally, each alpha-amino acid has a unique side chain (R group) that defines its properties and function in protein structures.

In nature, there are 20 standard alpha-amino acids, each contributing differently to protein function and structure. For instance, some side chains are hydrophobic, affecting how proteins fold and interact with lipid membranes. Others may be charged or polar, allowing the formation of hydrogen bonds and ionic interactions.

Understanding alpha-amino acids is crucial because they directly influence protein synthesis and enzymatic activity, impacting almost all biological processes.

Peptide Bonds

Peptide bonds are the chemical links that hold amino acids together in a peptide or protein chain. This bond forms through a dehydration synthesis reaction, where the carboxyl group of one amino acid reacts with the amino group of another, releasing water (\( H_2O \)).

The result is a covalent bond known as a peptide bond, represented as \(-CO-NH-\). This link is stable, crucial for maintaining the structure of proteins, and can withstand certain physiological conditions. The sequence of peptide bonds in a protein determines its primary structure, ultimately affecting the protein's function and activity.

Peptides vary in length, from just a few amino acids (oligopeptides) to long chains (polypeptides), forming complex protein structures with specific biological roles.

Amino Acids

Amino acids are organic compounds that combine to form proteins, the workhorses of the cell. Each amino acid consists of a basic amino group, an acidic carboxyl group, and an organic R group (or side chain) that is unique to each amino acid. These individual elements contribute to their diverse roles in metabolism, growth, and repair.

Amino acids are classified into essential and non-essential categories. Essential amino acids cannot be synthesized by the human body, so they must be obtained from the diet. In contrast, non-essential amino acids can be produced internally.

Understanding the role of amino acids is vital because their structure and interactions determine the specific functions of proteins, influencing everything from enzyme behavior to nutrient transport and DNA replication. This makes amino acids fundamental to life processes and health.