1.2: Transport Across Membranes

Question 1

What are cell membranes made from?

Answer 1

They are made from phospholipids, proteins and are selectively permeable

Question 2

What is passive transport?

Answer 2

Transport that occurs down a concentration gradient and does not require energy

Question 3

What are the two types of passive transport?

Answer 3

Diffusion and Osmosis

Question 4

What is diffusion?

Answer 4

The movement of molecules down a concentration gradient from a higher to a lower concentration

Question 5

What is osmosis?

Answer 5

The movement of water molecules from a higher water concentration to a lower water concentration

Question 6

What happens when an animal cell is placed in a salty/sugary solution?

Answer 6

Water will move out of the cell by osmosis and it will shrink

Question 7

What happens when an animal cell is placed in pure water?

Answer 7

Water will move into the cell by osmosis and it will burst

Question 8

What happens when a plant cell is placed into a salty/sugary solution?

Answer 8

Water will move out of the cell by osmosis and it will become plasmolysed

Question 9

What happens when a plant cell is placed in pure water?

Answer 9

Water will move into the cell by osmosis and it will become turgid

Question 10

What is active transport?

Answer 10

The movement of molecules against the concentration gradient that requires energy

Question 11

Why does active transport require energy?

Answer 11

For membrane proteins to move molecules and ions against the concentration gradient