The cytoskeleton of a cell is comprised of which of the following macromolecules?
A.
Carbohydrates
B.
Nucleic acids
C.
Lipids
D.
Proteins.
The Correct Answer and Explanation is:
The correct answer is D. Proteins.
Explanation:
The cytoskeleton is a critical component of the cell’s internal structure and is predominantly composed of proteins. It provides structural support, maintains cell shape, facilitates intracellular transport, and is involved in various cellular processes including division and motility. The cytoskeleton consists of three main types of protein fibers: microfilaments, intermediate filaments, and microtubules.
- Microfilaments: These are the thinnest components of the cytoskeleton, primarily composed of actin, a globular protein. Microfilaments are involved in various functions, such as muscle contraction, cell movement, and the maintenance of cell shape. They also play a crucial role in cytokinesis, the process of cell division where the cell membrane pinches inwards to form two daughter cells.
- Intermediate Filaments: These filaments are more stable and less dynamic compared to microfilaments and microtubules. They are composed of various proteins, such as keratins, vimentin, and neurofilaments, depending on the cell type. Intermediate filaments provide mechanical strength to the cell, helping it withstand stress and maintain its shape. They anchor organelles and contribute to the structural integrity of the cell.
- Microtubules: These are the largest cytoskeletal components and are made up of tubulin proteins. Microtubules are crucial for maintaining cell shape, enabling intracellular transport, and facilitating cell division through their role in forming the mitotic spindle. They also provide tracks for the movement of organelles, vesicles, and other cellular components.
The cytoskeleton’s role in cellular function and organization underscores its importance in cell biology. Unlike carbohydrates, nucleic acids, and lipids, which have different primary functions such as energy storage, genetic information storage, and cell membrane formation respectively, the cytoskeleton’s function is directly related to the physical structure and organization of the cell.
Overall, the cytoskeleton’s protein-based structure is essential for numerous cellular processes and ensures the cell’s ability to function properly and adapt to various conditions.