U1 KA2 : Transport Across Cell Membranes

Question 1

What is the Cell Membrane made up of?

Answer 1

• Proteins and Phospholipids.

Question 2

What special characteristic does the Cell Membrane have?

Answer 2

• it is SELECTIVELY PERMEABLE as it only lets some substances pass through it.

Question 3

What is Passive Transport?

Answer 3

• the movement of molecules down a concentration gradient (without requiring energy).

Question 4

Give 2 examples of Passive Transport.

Answer 4

• Osmosis
• Diffusion

Question 5

What is Diffusion?

Answer 5

• the movement of a substance from an area of high concentration to an area of low concentration down a concentration gradient.

Question 6

What is the importance of Diffusion in a cell?

Answer 6

• it allows raw materials like oxygen to enter a cell, and waste materials like carbon dioxide to exit.

Question 7

What is Osmosis?

Answer 7

• the movement of water molecules from an area of high water concentration to an area of low water concentration, through a selectively permeable membrane and down a concentration gradient.

Question 8

What is the effect of Osmosis on a Plant Cell?

Answer 8

• Turgid or Plasmolysed.

Question 9

What is the effect of Osmosis on an Animal Cell.

Answer 9

• Bursts or Shrinks.

Question 10

What is Active Transport?

Answer 10

• the movement of molecules across a membrane up a concentration gradient, requiring energy.