Topic 2B

Question 1

Cell surface membrane

Answer 1

Barrier between cell and environment. Partially permeable

Question 2

Phospholipid bilayer

Answer 2

Head is hydrophilic and tail hydrophobic automatically forming bilateral
Centre of the bilateral is hydrophobic so membrane doesn’t allow water soluble substances through acts as barrier to dissolved substance

Question 3

Cholesterol

Answer 3

Type of lipid
Present in all cell membranes (except bacterial)
Fit between phospholipids, bind to the hydrophobic tails packing closer together restricting movement
Helps maintain shape of animal cells

Question 4

Diffusion

Answer 4

Net movement of particles from area of higher concentration to an area of lower concentration

Question 5

Facilitated diffusion

Answer 5

When large molecules or charged particles diffuse through carrier proteins or channel proteins

Question 6

Carrier proteins

Answer 6

Large molecule attaches to carrier protein changing the proteins shape and causing it to be released on the opposite side

Question 7

Channel proteins

Answer 7

Form pores in the membrane for charges particles to diffuse through

Question 8

Simple diffusion

Answer 8

When molecules diffuse directly through a cell membrane

Question 9

Osmosis

Answer 9

Diffusion of water molecules across a partially permeable membrane from an area of higher water potential to an area of lower water potential

Question 10

Active transport

Answer 10

Move molecules and ions across membrane against concerntration gradient using energy

Question 11

What happens to bilayer above 45C

Answer 11

Breaks down and membrane permeable. Water inside cell expands putting pressure on membrane.
Channel and carrier proteins deform

Question 12

Co-transport

Answer 12

Coupled movement of one molecule with its concentration traditionally and another molecule against its concentration gradient

Question 13

Process of co-transport

Answer 13

Sodium ions actively transported out of ileum of epithelial cell into blood by potassium sodium pump
Causes sodium ions to diffuse from lumen into epithelial cell via sodium glucose transporter proteins
Cotransporter carries glucose into cell with sodium
Glucose diffuses out of cell into blood down concentration gradient by facilitated diffusion

Question 14

Ficks law

Answer 14

Rate of diffusion is directly proportional to SA x Conc gradient/ length of diffusion pathway

Question 15

How many of each ion in sodium potassium pump

Answer 15

2 potassium in and 3 sodium’s out

Question 16

Turgor pressure

Answer 16

The force within the cell that pushes the plasma membrane against the cell wall when the vacuole swells

Question 17

Lysed

Answer 17

When water moves into the cell in a animal cell

Question 18

Plasmolyzed

Answer 18

When water moves out the cell into surrounding in plant cells