Which one of the following is wrongly matched ?

Question

Accepted Answer

Option 4 is correctly identified as the wrongly matched pair: "Troponin – Fibrous protein." Here's a detailed explanation:

1. **Troponin – Fibrous protein (Option 4):**
   - Troponin is not a fibrous protein; it is a complex of three regulatory proteins (troponin C, troponin I, and troponin T) that are integral to muscle contraction in skeletal and cardiac muscle. These proteins are involved in the regulation of calcium-mediated muscle contraction. Troponin binds to calcium ions and helps in the regulation of actin and myosin interactions, which are crucial for muscle contraction. Therefore, classifying troponin as a fibrous protein is incorrect, making this option the wrongly matched pair.

2. **Tendon – Connective tissue (Option 1):**
   - Tendons are indeed a type of connective tissue. They connect muscle to bone and are composed of collagen fibers, which provide strength and flexibility. This option is correctly matched, as tendons are a well-known example of connective tissue.

3. **Smooth muscles – Involuntary muscle (Option 2):**
   - Smooth muscles are correctly described as involuntary muscles. They are found in the walls of internal organs such as the stomach, intestines, and blood vessels, and they function without conscious control. This option is correctly matched.

4. **Red muscles – Myoglobin (Option 3):**
   - Red muscles, also known as slow-twitch muscles, are rich in myoglobin, a protein that binds oxygen and gives these muscles their red color. Myoglobin helps in the storage and transport of oxygen within muscle cells, which is essential for endurance activities. This option is correctly matched.

In conclusion, Option 4 is the correct answer because it incorrectly matches troponin with fibrous protein, whereas troponin is actually a regulatory protein complex involved in muscle contraction. The other options are correctly matched based on their respective definitions and functions.