Most abundant protein in the whole biosphere is

Options

A. Collagen
B. Myosin sulshrete
C. RUBISCO
D. Actin

Answer

To determine the most abundant protein in the whole biosphere, we need to analyze the options provided:

1. **Collagen**:
- Collagen is indeed the most abundant protein in the animal kingdom and serves as a key component of connective tissues. However, it is not the most abundant protein in the entire biosphere, as it is limited to animals.

2. **Myosin Sulfate**:
- Myosin is a protein involved in muscle contraction and is found in animal cells. While it is important, it is not the most abundant protein in the biosphere.

3. **Rubisco**:
- Rubisco, or ribulose-1,5-bisphosphate carboxylase/oxygenase, is an enzyme that plays a crucial role in the process of photosynthesis. It catalyzes the first major step of carbon fixation, which is the conversion of carbon dioxide into organic compounds. Due to its essential role in photosynthesis and the vast number of plants and photosynthetic organisms on Earth, Rubisco is considered the most abundant protein in the entire biosphere.

4. **Actin**:
- Actin is a protein that forms microfilaments and is involved in various cellular functions, including muscle contraction and cell movement. While it is abundant in animal cells, it does not surpass Rubisco in terms of overall abundance in the biosphere.

Based on this analysis, the correct answer is **C. Rubisco**, as it is the most abundant protein in the whole biosphere due to its critical role in photosynthesis.