---
title: "Active Transport Against the Gradient"
description: "A cell can move substances from a low concentration to a high one by spending energy released in respiration. Covers mineral ion uptake by root hairs and glucose absorption from the small intestine."
canonical: https://lightmysky.com/learn/science/active-transport-against-the-gradient-mt_BQf1bgo9oM
source: https://lightmysky.com/learn/science/active-transport-against-the-gradient-mt_BQf1bgo9oM.md
retrieved: 2026-09-12
---

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# Active Transport Against the Gradient

A cell can move substances from a low concentration to a high one by spending energy released in respiration. Covers mineral ion uptake by root hairs and glucose absorption from the small intestine.

Subject: Science · Area: Organisms & Life Processes · Ages 14 to 15
Page: https://lightmysky.com/learn/science/active-transport-against-the-gradient-mt_BQf1bgo9oM

## Ready when they can

- States the direction of movement that separates active transport from diffusion and osmosis.
- Links the number of mitochondria in a cell to how much active transport it does.
- Explains why a root that cannot respire stops taking up minerals even though the water keeps coming in.

## Lesson: Pumping uphill with energy

After PE Priya breathes fast because her muscles need energy from respiration to keep working. Diffusion and osmosis run downhill, from crowded to spread out, and cost nothing. Active transport runs uphill, from a low concentration to a high one, and the cell pays for the climb with ATP from respiration.

**Example.** Root hairs sip mineral ions from poor soil where ions are scarce. The ions move into the root against the gradient, paid for by ATP. Water still enters the same root by osmosis, which costs no energy at all.

Cells that pump hard carry extra power stations. Root hair cells and gut lining cells are packed with mitochondria because they move so much stuff uphill. The sodium potassium pump spends ATP to push sodium out and pull potassium in, and nerves use it to reset after each signal.

To test whether a movement is active, cut the energy supply. If the movement stops while diffusion and osmosis carry on, it was active transport. A root that cannot respire stops taking up minerals, but water keeps coming in.

**Recap.** Active transport spends ATP to move substances uphill, and it stops when respiration stops.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Aerobic Respiration](https://lightmysky.com/learn/science/aerobic-respiration-mt_mquPi2IP-J)
- [Osmosis in Plant and Animal Cells](https://lightmysky.com/learn/science/osmosis-in-plant-and-animal-cells-mt_XciCLO69xG)

## Opens up

- [Surface Area to Volume Ratio and Exchange Surfaces](https://lightmysky.com/learn/science/surface-area-to-volume-ratio-and-exchange-surfaces-mt_1TclgVUxfa)
- [Co-transport and Coupled Movement Across Membranes](https://lightmysky.com/learn/science/co-transport-and-coupled-movement-across-membranes-mt_pzQ8n3FWNV)
- [Digestion and Absorption in the Mammalian Gut](https://lightmysky.com/learn/science/digestion-and-absorption-in-the-mammalian-gut-mt_xZ2-3ZClDa)