Cell membrane

Definition

The cell membrane is a selectively permeable barrier that surrounds the cytoplasm of a cell, regulating the movement of substances in and out. In prokaryotic cells, it also plays a crucial role in energy generation and maintaining cellular homeostasis.

5 Must Know Facts For Your Next Test

1. The cell membrane is composed primarily of a phospholipid bilayer with embedded proteins.
2. It controls the transport of nutrients, waste products, and other molecules into and out of the cell.
3. In prokaryotic cells, the cell membrane is involved in processes such as respiration and photosynthesis since they lack organelles like mitochondria and chloroplasts.
4. The fluid mosaic model describes the structure of the cell membrane with its dynamic nature allowing lateral movement of components within the layer.
5. Proteins in the cell membrane can act as receptors, transport channels, or enzymes facilitating various cellular functions.

Review Questions

• What are the primary components of a prokaryotic cell's membrane?
• How does the cell membrane contribute to a prokaryotic cell's energy generation?
• Explain how the fluid mosaic model relates to the structure and function of the cell membrane.

Related terms

Phospholipid Bilayer: A double layer of phospholipids that forms the fundamental structure of all cellular membranes.

Selective Permeability: The ability of a cell membrane to regulate which molecules can pass through it.

Fluid Mosaic Model: A model describing the dynamic arrangement and movement of molecules within the lipid bilayer.