Which pigment/s is/are required for the mechanism of vision?

Options

A. Opsin
B. Retinal
C. Both opsin and retinal
D. None of these

Answer

To answer the question regarding which pigment/s are required for the mechanism of vision, we can break down the solution into the following steps:

### Step 1: Identify the pigments involved in vision
The two primary pigments involved in the mechanism of vision are **Opsin** and **Retinal**.

### Step 2: Understand the role of Opsin
Opsin is a protein molecule that plays a crucial role in the phototransduction process. When light hits the photoreceptor cells in the retina, Opsin undergoes a conformational change, which is essential for sending chemical signals to the brain.

### Step 3: Understand the role of Retinal
Retinal is a derivative of Vitamin A and is responsible for detecting photons (light particles). When light is absorbed, Retinal changes its configuration, which triggers a series of biochemical reactions.

### Step 4: Explain the interaction between Opsin and Retinal
When Retinal changes configuration upon absorbing light, it pushes against the Opsin protein. This interaction is vital for the signal transduction pathway that ultimately leads to the perception of light by the brain.

### Step 5: Conclude the answer
Both Opsin and Retinal are necessary for the mechanism of vision. Therefore, the correct answer to the question is that both pigments are required.

### Final Answer:
**Opsin and Retinal are required for the mechanism of vision.**

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