Transport Across Cell Membrane N5 U1 P2

Question 1

Selectively permeable

Answer 1

Molecules are allowed to pass through based on their size

Question 2

What is the cell membrane made of

Answer 2

Composed of phospholipids and proteins
Some proteins have channels to allow molecules to pass in and out
Phospholipids are organised as a bilayer

Question 3

Passive transport

Answer 3

During Passover transport molecules move down the coneentration gradient
No energy is needed
The difference in concentration[gradient] that causes molecules to move
Diffusion and osmosis are examples of passive transport

Question 4

Diffusion definition

Answer 4

Diffusion is the movement of molecules from a higher concentration to a lower concentration down the concentration gradient

Question 5

Chemicals that will diffuse

Answer 5

Diffusion of chemicals is important to all cells
Carbon dioxide
Oxygen
Glucose
Amino acids

Question 6

Osmosis definition

Answer 6

Osmosis is the movement of water molecules from a higher concentration to a lower concentration down a concentration gradient through a selectively permeable membrane

Question 7

Osmosis in plant cells-effect of high water concentration

Answer 7

Described as turgid
Higher water concentration outside cell so water moves down concentration gradient into cell

Question 8

Osmosis in plant cells-effect of lower water concentration

Answer 8

Described as plasmolysed
Higher water concentration inside cell so water moves down concentration gradient out of cell

Question 9

Animal cell osmosis- effect of higher water concentration

Answer 9

Higher water concentration causes cell to burst, this is because they have no cell wall
Higher water concentration outside cell, water moves down concentration into cell

Question 10

Animal cell osmosis- effect of lower water concentration

Answer 10

Lower water concentration causes cell to shrink as they don’t have cell wall to support structure
Higher water concentration inside cell water moves down concentration gradient out of cell

Question 11

Active transport

Answer 11

During active transport, molecules and ions are transported against the concentration gradient
Requires energy
Proteins in the membrane pump molecules and ions across the e membrane