Who domonstrated that photosynthesis is essentially a light-dependent reaction?

Options

A. Cornelius van Niel
B. Julius van Sach
C. Ingenhousz
D. T.W. Engelmass

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose (food) using carbon dioxide and water. This process is essential for the survival of these organisms and for life on Earth.

2. **Light-Dependent Reactions**: Photosynthesis consists of two main stages: light-dependent reactions and light-independent reactions (Calvin cycle). The light-dependent reactions occur in the thylakoid membranes of chloroplasts and require sunlight to produce energy-rich compounds (ATP and NADPH) and oxygen.

3. **Historical Context**: The question asks about the scientist who first demonstrated that photosynthesis is a light-dependent reaction. This is a significant aspect of understanding how plants convert light energy into chemical energy.

4. **Identifying the Scientist**: The scientist who proposed that photosynthesis is essentially a light-dependent reaction is **Cornelius Van Niel**. He conducted experiments that showed the necessity of light for the process of photosynthesis and how carbon dioxide is reduced to carbohydrates while water is oxidized.

5. **Conclusion**: Therefore, the correct answer to the question is **Cornelius Van Niel**.

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