The tails of myosin are made up of

Options

A. Light meromyosin
B. Globular actin
C. Heavy meromyosin
D. Filamentous actin

Answer

To answer the question "The tails of myosin are made up of," we can break down the information as follows:

### Step-by-Step Solution:

1. **Understanding Myosin Structure**: Myosin is a motor protein that plays a key role in muscle contraction. It consists of two main parts: a head and a tail.

2. **Identifying Myosin Components**: The myosin molecule is composed of heavy meromyosin and light meromyosin. The heavy meromyosin includes the globular head and a neck region, while the light meromyosin forms the tail.

3. **Distinguishing Between Actin and Myosin**: Actin is another protein found in muscle fibers, but it is distinct from myosin. There are two forms of actin: globular actin (G-actin) and filamentous actin (F-actin). However, these are not part of the myosin structure.

4. **Focusing on the Tail Composition**: The tail of myosin is specifically made up of light meromyosin. This part does not have any active sites for binding ATP or actin; instead, it serves as a structural component.

5. **Final Answer**: Therefore, the tails of myosin are made up of **light meromyosin**.