Cell Transport and Membrane Functions

This page explores the fundamental concepts of cellular transport mechanisms and membrane characteristics. The content covers structural differences between cell walls and membranes, transport processes, and membrane permeability.

Definition: Cell membrane is a flexible structure made of lipids and proteins that regulates cellular entry and is present in all cells, while cell walls are rigid structures not found in all cell types.

Highlight: The cell membrane serves three crucial functions: regulating substance movement, maintaining homeostasis, and providing cellular flexibility.

Vocabulary: Selectively permeable (or semi-permeable) refers to the membrane's ability to allow certain substances to pass through while blocking others.

Definition: Passive transport is the movement of molecules from areas of high concentration to low concentration until equilibrium is reached.

Example: Simple diffusion, a type of passive transport, can be observed in everyday situations like:

• Perfume dispersing through air
• Air freshener spreading in a room
• Food coloring dispersing in water

Highlight: Equilibrium is achieved when the concentration becomes uniform throughout the system, marking the end point of passive transport processes.