2.1.5 Plasma Membranes

Question 1

Plasma membrane

Answer 1

Phospholipid bilateral

Hydrophilic phosphate heads
Hydrophobic fatty acid tail core

Question 2

Compartmentalisation

Answer 2

The formation of seperate membrane-bound areas in a cell

Question 3

Fluid mosaic model

Answer 3

Phospholipids drew to move within layer

Proteins embedded in the bilayer

Question 4

Intrinsic proteins

Answer 4

Embedded in both layers

Hydrophobic R-groups on surface

Question 5

Factors affecting membrane structure

Answer 5

Temp: increases KE so moves more. Loses structure and proteins denature

Organic solvents: will dissolve membranes, become leaky

Question 6

Diffusion

Answer 6

The net movement of particles from a region of higher concentration to a region of lower concentration

Down a conc gradient

Passive

Question 7

Active transport

Answer 7

Movement of molecules/ions from lower to higher concentration
Against a concentration gradient

Requires energy — active

Question 8

Transport

Answer 8

Bulk transport: large molecules

Endocytosis: into cell

Exocytosis: out of cell

Question 9

Osmosis

Answer 9

The movement of water from high to low concentration down a water potential gradient

Question 10

Water potential

Answer 10

The pressure exerted by water as they collide with a membrane or container