Cell Membrane and Membrane Transport

These flashcards cover key terms and concepts related to the structure and function of the cell membrane, including membrane components, transport mechanisms, and permeability principles.

Plasma membrane

Forms the boundary of cells and determines the movement of substances in and out of the cell.

Fluid mosaic model

Describes the structure of the plasma membrane as fluid-like due to its viscous nature and the variety of molecules embedded within.

Glycolipids

Lipids with sugar attached, found in the cell membrane.

Glycoproteins

Proteins with sugar attached, present in the membrane and play a role in cell recognition.

Transmembrane proteins

Integral proteins that pass through the membrane.

Membrane permeability

The ability of certain substances to cross the plasma membrane, with small nonpolar molecules passing freely and polar/charged molecules not able to move freely.

Concentration gradient

A difference in concentration of a substance across a membrane.

Diffusion

The random motion that causes substances to move from an area of higher concentration to lower concentration.

Dynamic equilibrium

Occurs when concentration is equal on both sides of the membrane, allowing diffusion to continue in both directions equally.

Osmosis

The diffusion of water across a membrane, occurring from low to high solute concentration.

Aquaporin

A membrane protein that facilitates the rapid passage of water across the membrane.

Semipermeable membrane

A membrane that allows some molecules to pass through while blocking others.