Based upon the number of NH2 and COOH amino acids are -

Options

A. 3 types
B. 2 types
C. 4 types
D. 20 types

Answer

To answer the question about the classification of amino acids based on the number of amino groups (NH2) and carboxyl groups (COOH), we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding Amino Acids**: Amino acids are organic compounds that serve as the building blocks of proteins. Each amino acid contains at least one amino group (NH2) and one carboxyl group (COOH).

2. **Classification Criteria**: Amino acids can be classified based on the number of amino groups and carboxyl groups they possess. The three classifications are:
- **Acidic Amino Acids**: These amino acids have more carboxyl groups than amino groups. They typically contain an additional carboxyl group in their side chain (R group). Examples include aspartic acid and glutamic acid.
- **Basic Amino Acids**: These amino acids have more amino groups than carboxyl groups. They usually contain an additional amino group in their side chain. Examples include lysine, arginine, and histidine.
- **Neutral Amino Acids**: These amino acids have equal numbers of amino and carboxyl groups. They do not have additional carboxyl or amino groups in their side chains. Examples include glycine and alanine.

3. **Conclusion**: Based on the number of NH2 and COOH groups, amino acids can be classified into three types: acidic, basic, and neutral.

### Final Answer:
Based upon the number of NH2 and COOH groups, amino acids are classified into three types: acidic, basic, and neutral.

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