Active Transport in Action: Plants and Animals Revision Notes | GCSE OCR Foundation Biology

What this lesson covers

Explore real examples of active transport in living organisms, including how plant roots absorb mineral ions from soil and how sugar is absorbed in the...

• Explain how active transport allows plants to absorb mineral ions from dilute soil solutions
• Describe how sugar molecules are absorbed from the gut into blood using active transport
• Compare active transport with diffusion and osmosis in terms of energy requirements
• Apply knowledge of active transport to explain why plants need this process for healthy growth

Key ideas to keep in view

Use this lesson to stay inside B2.1 Supplying the cell while connecting the detail back to the wider B2: Scaling up topic.

• B2: Scaling up
• B2.1 Supplying the cell
• GCSE OCR Foundation Biology

Lesson notes preview

Read the core explanations from Active Transport in Action: Plants and Animals before testing yourself from memory.

• 1. Why Cells Sometimes Need to Work Against Nature
• Your gut has just absorbed a sugary drink, but there's a problem. Your blood already contains more sugar than your intestines do. How does your body get that sugar from your gut into your bloodstream when it's moving against the natural flow?
• This is where active transport comes in. Unlike diffusion, which moves substances down concentration gradients, active transport can push substances uphill - from areas of low concentration to high concentration. It's like having a molecular escalator that only goes up.
• The movement of substances against their concentration gradient using energy from respiration.
• Trap: Many students think active transport is just 'fast diffusion'. Actually, it's the complete opposite - it moves substances against their natural gradient, which diffusion never does.
• 2. The Three Key Features of Active Transport
• Active transport has three non-negotiable requirements that make it different from passive processes like diffusion and osmosis.
• Energy Required: Active transport needs ATP from respiration. No energy means no transport. This is why cells with high active transport rates (like root hair cells) are packed with mitochondria.
• Active transport uses energy from respiration to move substances against the concentration gradient when diffusion cannot.
• Against the Gradient: This is the defining feature. Active transport moves substances from where there's less to where there's more - exactly opposite to diffusion.

Continue through the topic

Move to the related lessons or back to the topic page when you need the wider sequence before exam-style practice.