Translocation

Plant structures and their functions · Transport in plants · note 4 of 4

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TranslocationSpec 6.10

In short

Translocation is the transport of sucrose around the plant, dissolved in water in the phloem. Sucrose moves from the leaves, where it is made, to parts that use or store it, such as growing shoot tips, roots, flowers and fruits. It can move up or down, and needs energy released by respiration in the living phloem cells.

Translocation is the transport of sucrose around the plant. Sucrose is made from the glucose produced in photosynthesis, and it is carried dissolved in water in the phloem.

Sucrose moves from the leaves, where it is made, to the parts of the plant that use it or store it, such as growing shoot tips, roots, flowers and fruits.
It can move up and down the plant, depending on where it is needed.
Translocation needs energy, which is released by respiration in the living cells of the phloem.

A plant with arrows showing sucrose moving in the phloem from the leaves, where it is made, up to the growing shoot tip, along to a fruit and down to the root. — Translocation: sucrose moves in the **phloem** from the leaves to where it is used or stored, up and down the plant.

Exam tip:

Contrast it with transpiration: translocation moves sucrose in the phloem and uses energy. Transpiration moves water in the xylem and does not use energy from the plant's cells.

Quick check

Give two adaptations of a root hair cell.
Show answer
Any two of: a long, thin projection for a large surface area; many mitochondria for active transport; a thin cell wall.
Why is xylem made of lignified dead cells?
Show answer
Dead cells with no end walls form a continuous hollow tube for water, and lignin strengthens the walls.
What is transpiration?
Show answer
The loss of water vapour from the leaves, which pulls water through the plant.
What is translocation?
Show answer
The transport of sucrose around the plant in the phloem.

Written and checked against the Edexcel GCSE Biology (1BI0) specification · Updated October 2026

Frequently asked questions

How are root hair cells adapted to their function?

Root hair cells are adapted to absorb water and mineral ions from the soil. The long, thin root hair gives a large surface area, and the thin cell wall gives a short distance to cross. Many mitochondria release energy for the active transport of mineral ions, and concentrated cell sap lets water enter by osmosis.

Why is active transport needed in plant roots?

Active transport is needed because mineral ions, such as nitrate ions, are usually at a lower concentration in the soil water than inside the root hair cell. They cannot move in by diffusion, so they are moved from a lower to a higher concentration by active transport, which uses energy released by respiration in the mitochondria.

How does water move from roots to leaves?

Water moves from roots to leaves in the transpiration stream. Water is absorbed from the soil by root hair cells and moves up through the xylem to the leaves. It evaporates from the cells inside the leaf into the air spaces and diffuses out through the stomata. This loss of water pulls more water up the xylem.

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