Most abundant protein on earth is

Options

A. keratin
B. rubisco
C. RuBP
D. fibrinogen

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the most abundant protein on Earth. This requires knowledge of proteins and their functions in nature.

2. **Identifying Options**: The question likely provides multiple-choice options. Common proteins in nature include keratin, Rubisco, RUBP, and fibrinogen.

3. **Analyzing Each Option**:
- **Keratin**: This is a structural protein found in hair, nails, and skin. While it is abundant in certain organisms, it is not the most abundant protein overall.
- **Rubisco**: This is an enzyme known as ribulose bisphosphate carboxylase/oxygenase. It plays a crucial role in photosynthesis by fixing carbon dioxide. It is known to be the most abundant protein in the world, making up about 50% of the protein content in plant leaves.
- **RUBP**: This stands for ribulose bisphosphate, which is a substrate involved in the photosynthetic process but is not a protein itself.
- **Fibrinogen**: This is a protein involved in blood clotting but is not as abundant as Rubisco.

4. **Conclusion**: Based on the analysis, Rubisco is identified as the most abundant protein on Earth.

5. **Final Answer**: The most abundant protein on Earth is Rubisco (ribulose bisphosphate carboxylase/oxygenase).

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