Active Transport
Overview
Diffusion and osmosis are free, but they only ever move substances down a gradient. So how does a root hair cell pull mineral ions out of soil that is far more dilute than the cell itself? How do gut cells grab the last of the glucose when there is little left to absorb? The answer is active transport: moving substances uphill, against the gradient, by spending energy.
In this lesson you will learn exactly what active transport is, why cells need it, and, at Extended level, how protein carriers in the membrane and energy from respiration make it possible.
Objectives
- Describe active transport as the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (i.e. against a concentration gradient), using energy from respiration
- [Supplement] Explain the importance of active transport as a process for movement of molecules or ions across membranes, including ion uptake by root hairs
- [Supplement] State that protein carriers move molecules or ions across a membrane during active transport
Lesson Note
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Lesson Evaluation
Congratulations on completing the lesson on Active Transport. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Active transport moves particles: A. down the concentration gradient B. against the concentration gradient C. only when water moves D. without any energy Answer: B
- The energy for active transport comes from: A. sunlight B. diffusion C. respiration D. osmosis Answer: C
- Which cells use active transport to absorb mineral ions from dilute soil water? A. red blood cells B. root hair cells C. nerve cells D. palisade cells Answer: B
- Which would stop active transport? A. adding glucose B. a respiratory poison C. raising the concentration gradient D. adding oxygen Answer: B
- Active transport across a membrane is carried out by: A. chlorophyll B. ribosomes C. carrier proteins D. cellulose Answer: C
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Recommended Books
Practice Mock Questions
Want to practice mock questions on Active Transport? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.
Download The App On Google Playstore
Everything you need to excel in JAMB, WAEC & NECO
