Cell Membrane Structure and Transport Processes

These flashcards cover key concepts related to cell membrane structure and transport processes, crucial for understanding cell biology.

Plasma Membrane

A thin layer of lipids and proteins that separates a cell from its surroundings, typically 5 to 10 nm wide.

Fluid Mosaic Model

Proposes that the membrane consists of a fluid phospholipid bilayer in which proteins are embedded and float freely.

Lipid Bilayer

A double layer of phospholipids that makes up the cell membrane.

Integral Proteins

Proteins that penetrate the lipid bilayer and pass entirely through it.

Peripheral Proteins

Proteins located entirely outside of the lipid bilayer.

Lipid-anchored Proteins

Proteins covalently linked to a lipid molecule situated within the bilayer.

Diffusion

The process by which substances move across the membrane through the lipid bilayer.

Osmosis

The diffusion of water across a selectively permeable membrane.

Cholesterol

A sterol that maintains membrane fluidity and stability in animal cell membranes.

Glycolipids

Carbohydrates covalently linked to lipids that play a role in cell interactions.

Glycoproteins

Membrane proteins that have carbohydrate chains attached, playing roles in cell recognition and signaling.

Hydrophilic

Tending to mix with, or be dissolved in, water.

Hydrophobic

Repelling water; substances that do not mix with water.

Active Transport

The process of moving substances across the membrane against their concentration gradient, requiring energy.

Channel Proteins

Transport proteins that form channels allowing specific polar molecules and ions to pass.

Transport Proteins

Proteins that assist in the movement of substances across a cell membrane.