Bitesize GCSE Biology - Series 1: The Cell - Diffusion, Osmosis, and Active Transport
Overview
Series Title: Bitesize GCSE Biology
Episode: Series 1, Episode 7
Topic: Diffusion, Osmosis, and Active Transport
Release Date: March 23, 2023
Duration: 9 minutes
Available: for over a year
Key Concepts
1. Movement of Substances in Cells
Diffusion, osmosis, and active transport are the three main methods through which substances move in and out of cells.
2. Diffusion
Definition: The process by which particles move from an area of high concentration to an area of low concentration.
Characteristics:
Passive process (requires no energy)
Occurs in gases and liquids
Important for the exchange of gases (e.g., oxygen and carbon dioxide in the lungs)
3. Osmosis
Definition: The movement of water molecules through a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.
Characteristics:
Also a passive process
Crucial for maintaining cell turgor pressure in plants
4. Active Transport
Definition: The movement of substances against a concentration gradient, from low to high concentration, using energy.
Characteristics:
Requires energy (usually from ATP)
Allows cells to intake nutrients and expel waste products
Important in root hair cells for the absorption of minerals from the soil
Educational Context
Target Audience: Students preparing for GCSE Biology exams
Purpose: To provide a concise and clear explanation of how substances are transported in biological systems, reinforcing foundational biological concepts in cell biology.