Which of the following is not present in sweat ?

Options

A. Amino acid
B. NaCl
C. Lactic acid
D. Uric acid

Answer

To determine which of the following substances is not present in sweat, we will analyze each option provided:

1. **Amino Acid**: Sweat does contain a small amount of amino acids. These are organic compounds that serve as the building blocks of proteins and can be found in sweat.

2. **Sodium Chloride (NaCl)**: This is commonly known as table salt and is a major component of sweat. It helps in maintaining the electrolyte balance in the body.

3. **Lactic Acid**: This substance is also present in sweat. Lactic acid is produced during anaerobic respiration and can be excreted through sweat.

4. **Uric Acid**: Uric acid is primarily excreted through urine and is not typically found in sweat.

Based on this analysis, the substance that is **not present in sweat** is **Uric Acid**.

### Step-by-Step Solution:
1. **Identify the components of sweat**: Understand that sweat is primarily composed of water, sodium chloride (NaCl), amino acids, lactic acid, and urea.

2. **Evaluate each option**:
- **Amino Acid**: Present in sweat.
- **Sodium Chloride (NaCl)**: Present in sweat.
- **Lactic Acid**: Present in sweat.
- **Uric Acid**: Not present in sweat.

3. **Conclude**: The correct answer is **Uric Acid**, as it is not a component of sweat.