Cell Transport Mechanisms

This comprehensive page explores the fundamental concepts of cellular transport mechanisms, including diffusion, active transport, and osmosis. The content details how cells move materials across membranes and maintain proper functioning.

Definition: Diffusion is the spreading of particles from areas of high concentration to low concentration across a concentration gradient.

Highlight: Temperature and surface area directly affect diffusion rates - higher temperatures and larger surface areas result in faster diffusion.

Example: Oxygen diffuses into cells for respiration, while carbon dioxide diffuses out during gas exchange.

Definition: Active transport moves particles from low to high concentration areas against the concentration gradient, requiring energy.

Example: Root hair cells actively transport mineral ions like magnesium and nitrogen from dilute soil solutions.

Vocabulary: Isotonic - when internal and external concentrations are equal Vocabulary: Hypertonic - when external solution concentration is higher than internal Vocabulary: Hypotonic - when external solution concentration is lower than internal

Highlight: In plant cells, osmosis can lead to:

• Turgor: cell swelling due to water intake
• Plasmolysis: cell death due to excessive water loss

Example: The small intestine and lungs have specialized adaptations for efficient material exchange, including increased surface area through structures like villi and alveoli.