Transport Across The Membrane

Question 1

Name the 2 substances that the cell membrane is composed of

Answer 1

1. Proteins

2. Phospholipids

Question 2

What is the name given to the cell membrane as it only allows some molecules to pass through it but no others?

Answer 2

Selectively permeable

Question 3

What 2 properties must a substance have for it to be ale to pass through the membrane?

Answer 3

Small and soluble

Question 4

When does a concentration gradient exist?

Answer 4

When there is a difference in concentration between 2 areas

Question 6

Define osmosis

Answer 6

The movement of water molecules from an area of high concentration to an area of low concentration down a concentration gradient

Question 7

Define active transport

Answer 7

The movement of molecules and ions from an area of low concentration to an area of high concentration against a concentration gradient

Question 8

Name 3 substances that can enter a cell by diffusion

Answer 8

• glucose
• amino acids
• oxygen

Question 9

Name the waste products that leave a cell by diffusion

Answer 9

• carbon dioxide

* urea

Question 10

What form of energy does active transport require?

Answer 10

ATP (Adenosine Triphosphate)

Question 11

Define diffusion

Answer 11

The movement of molecules from an area of high concentration to an area of low concentration down a concentration gradient