B2.1.3

Question 1

What is active transport

Answer 1

Active transport allows cells to move substances from an area of low concentration to an area of high concentration. As particles are moving against the concentration gradient energy must be transferred.

Question 2

Features of active transport

Answer 2

.Particles are transported (pumped) against a concentration gradient
.ATP is required - this comes from respiration
.The process makes use of carrier proteins in the cell membrane

Question 3

How do carrier proteins work

Answer 3

The carrier protein takes the useful molecule.
The transport protein rotates and releases molecule inside cell using (ATP)
Transport protein then rotates back using ATP

Question 4

When is active transport used

Answer 4

It is used whenever a substance needs to be moved against a concentration gradient