Membranes Key Words 2

Question 1

Turgor

Answer 1

Pressure exerted by fluid in a cell that presses the plasma membrane against the cell wall. Makes living plant tissue rigid, loss results in wilting.

Question 2

Plasmolysis

Answer 2

Shrinking of protoplasm away from the cell wall of a plant in hypertonic solution

Question 3

Phospholipid

Answer 3

Amphipathic cell surface membrane component. Hydrophobic fatty acid tails and hydrophilic phosphate head attached to glycerol molecule.

Question 4

Osmosis

Answer 4

Passive water movement across a partially permeable membrane down a concentration gradient.

Question 5

Water potential

Answer 5

Measure of water molecule tendency to diffuse to another area. Unit kPa

Question 6

Isotonic

Answer 6

Solution where solute concentration is balanced with cell solute concentration.

Question 7

Hypotonic

Answer 7

Solution where solute concentration is lower than cell solute concentration Water moves into cell, causing swelling/lysis/turgor

Question 8

Hypertonic

Answer 8

Solution where solute concentration is higher than cell solute concentration. Water moves out of cell, shrivelling/cremation.

Question 9

Fluid mosaic model

Answer 9

Membrane structure model: phospholipid bilayer with cholesterol and proteins embedded.

Question 10

Ion pump

Answer 10

Transmembrane protein moves ions across plasma membrane against concentration gradient

Question 11

Osmolarity

Answer 11

Solute concentration measure, number of solute osmoles per litre of solution