2% of adult globin in humans is made of

Options

A. `alpha_(2)epsi_(2)`
B. `zeta_(2)gamma_(2)`
C. `alpha_(2)del_(2)`
D. `alpha_(2)gamma_(2)`.

Answer

To solve the question "2% of adult globin in humans is made of," we need to understand the composition of adult hemoglobin, which consists of globin proteins. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Globin**:
- Globin is a type of protein that forms part of hemoglobin, which is responsible for oxygen transport in the blood.

2. **Composition of Hemoglobin**:
- Hemoglobin is made up of two main components: the heme group (which contains iron) and the globin part (the protein component).

3. **Types of Globin Chains in Adult Hemoglobin**:
- In adult humans, hemoglobin (specifically Hemoglobin A) is composed of four polypeptide chains:
- 2 alpha (α) chains
- 2 beta (β) chains

4. **Amino Acid Count**:
- Each alpha chain consists of 141 amino acids, and each beta chain consists of 146 amino acids.
- Therefore, the total number of amino acids in adult hemoglobin can be calculated as follows:
- Total amino acids = (2 × 141) + (2 × 146) = 282 + 292 = 574 amino acids.

5. **Identifying the Correct Answer**:
- The question asks for what constitutes 2% of adult globin in humans. Given the composition of adult hemoglobin, the correct answer is that 2% of adult globin is made up of 2 alpha chains and 2 beta chains.

### Final Answer:
2% of adult globin in humans is made up of **2 alpha chains and 2 beta chains**.

---