Amino acids have peptide linkage which is

Options

A. `-CO-NH-`
B. `-C-NH_(2)`
C. `SO-NH-`
D. `-CO-N-`

Explanation

To understand the peptide linkage in amino acids, let's break down the concept step by step.

### Step 1: Understanding the Structure of Amino Acids
Amino acids are organic compounds that serve as the building blocks of proteins. Each amino acid has a general structure represented by the formula NH2-CHR-COOH. Here:
- NH2 is the amino group.
- R is the variable side chain that determines the specific properties of each amino acid.
- COOH is the carboxylic acid group.

### Step 2: Formation of Peptide Linkage
When two or more amino acids come together, they form a peptide bond through a condensation reaction. This process involves:
- The amino group (NH2) of one amino acid reacting with the carboxylic acid group (COOH) of another amino acid.
- During this reaction, a molecule of water (H2O) is released.

The reaction can be represented as:
\[ \text{Amino Acid 1 (NH2-CHR1-COOH)} + \text{Amino Acid 2 (NH2-CHR2-COOH)} \rightarrow \text{Dipeptide (NH2-CHR1-CO-NH-CHR2-COOH)} + H2O \]

### Step 3: Characteristics of Peptide Linkage
The bond formed between the carbon atom of the carboxylic group of one amino acid and the nitrogen atom of the amino group of another amino acid is known as a peptide bond or peptide linkage. This linkage is characterized by:
- A covalent bond (strong bond).
- The formation of a dipeptide if only two amino acids are involved.
- The potential to form longer chains (tripeptides, tetrapeptides, polypeptides) as more amino acids are added.

### Step 4: Examples of Peptides
- A dipeptide consists of two amino acids.
- A tripeptide consists of three amino acids.
- A polypeptide is a longer chain of amino acids, which can form proteins.

### Step 5: Conclusion
In summary, the peptide linkage is a crucial bond in biochemistry that connects amino acids together to form proteins. The general reaction involves the removal of water and the formation of a covalent bond between the amino and carboxyl groups of amino acids.

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