Back to 课程

Biology AS CIE

0% Complete
0/0 Steps
  1. 1-cell-structure
    10 主题
  2. 2-biological-molecules
    19 主题
  3. 3-enzymes
    13 主题
  4. 4-cell-membranes-and-transport
    16 主题
  5. 5-the-mitotic-cell-cycle
    8 主题
  6. 6-nucleic-acids-and-protein-synthesis
    9 主题
  7. 7-transport-in-plants
    11 主题
  8. 8-transport-in-mammals
    16 主题
  9. 9-gas-exchange
    6 主题
  10. 10-infectious-diseases
    6 主题
  11. 11-immunity
    10 主题
课 4, 主题 10
In Progress

4-2-movement-into-and-out-of-cells AS active-transport

课 Progress
0% Complete

Exam code:9700

The process of active transport

  • Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration

  • Active transport requires carrier proteins (each carrier protein being specific for a particular type of molecule or ion)

  • Although facilitated diffusion also uses carrier protein, active transport is different as it requires an input of additional energy

    • The energy is required to make the carrier protein change shape, allowing it to transfer the molecules or ions across the cell membrane

    • The energy required is provided by hydrolysis of ATP (adenosine triphosphate), which is produced during respiration

Diagram showing facilitated diffusion of polar molecules via specific carrier proteins through a phospholipid bilayer, from low to high concentration.
A carrier protein changing shape during active transport

Examiner Tips and Tricks

Be careful not to get carrier proteins and channel proteins confused when answering questions on active transport.

Active transport requires carrier proteins (transmembrane transport proteins that undergo conformational change) not channel proteins.

Responses

您的邮箱地址不会被公开。 必填项已用 * 标注