Diffusion and Osmosis

Question 1

osmosis

Answer 1

the movement of water from an area of high water conc to low water conc across a semi permeable membrane

Question 2

diffusion

Answer 2

the movement of molecules from an area of high conc to low conc (eg) gases move by diffusion in lungs o2 -> co2

Question 3

active transport

Answer 3

the movement of molecules using energy

Question 4

passive transport

Answer 4

the movement of molecules without using energy

Question 5

permeable

Answer 5

everything in and out

Question 6

semi permeable

Answer 6

some in and out

eg of some with semi permeable: mitochondria, nucleus

Question 7

impermeable

Answer 7

nothing in it out

Question 8

what type of transport is osmosis’s

Answer 8

passive - special type of energy

Question 9

solvent

Answer 9

a liquid that dissolves other substances

water

Question 10

solute

Answer 10

a substance that can be dissolved in water

salt sugar

Question 11

solution

Answer 11

made up of a solute and solvent mixed together

eg: salt water

Question 12

what happens when an animal cell (blood cell) is placed in a hypotonic soln eg:distilled water

Answer 12

water enters cell by osmosis
cell fills with water and expands
it may burst and die as there’s no wall
this is called haemolysis

Question 13

hypotonic

Answer 13

high water conc and low solute conc

Question 14

what happens when an animal cell (blood cell) is placed in a hypertonic soln eg: salty water

Answer 14

water leaves the cell by osmosis
cell shrinks and loses its shape and may die
this is called crenation

Question 15

hypertonic

Answer 15

low water conc high solute conc

Question 16

osmoregulagion

Answer 16

the control of the water and salt balance in an organism

multicellular organisms need to monitor the internal environment for water and salt balance

Question 17

homeostasis

Answer 17

maintains a constant internal environment
eg: salt and water balance

Question 18

isotonic

Answer 18

any external solution that has the same solute concentration and water concentration compared to body temp

Question 19

what happens when a plant cell (onion) is placed in a hypotonic skin eg: distilled water

Answer 19

water will move into cell by osmosis
water will pass into vacuoles and cytoplasm
these will swell and will force the cell membrane against the wall
the cel is now stronger and formed due to turgar pressure
cell is said to be turgid

Question 20

turgor pressure

Answer 20

the pressure of the vacuole and cytoplasm against the cell wall

Question 21

what happens when a plant cell (onion) is placed in a hypertonic soln eg:salty water

Answer 21

water will move out of the cell by osmosis
cell loses turgor and becomes weaker
cytoplasm shrinks and cell membrane pulls away from cell wall
cell is said to be PLASMOLOYSED and the plant is seen to wilt

Question 22

osmosis and food preservation - bacteria

Answer 22

bacteria and fungi cause food decay
if they’re placed in very concentrated solns they will lose water by osmosis
This prevents them from growing and causing food decay (eg:) tinned foods, sardines, jam, fruits

Question 23

osmosis and food preservation - amoeba

Answer 23

single celled organisms like amoeba don’t have a cell wall and need to protect themselves from influx of water
They have a CONTRACTILE VACUOLE which expels excess water from the cell
Example of osmoregulation

Question 24

example of osmoregulation

Answer 24

contractile vauole in amoeba to prevent influx of water

Question 25

animal cells in soln the same conc as their cytoplasm

Answer 25

water will move in and out
volume of cell remains same

Question 26

cell wall permeability

Answer 26

fully permeable

Question 27

experiment:

Answer 27

soak busking tubing in water to soften
tie knot
dissolve sucrose in warm water, hypertonic soln
fill busking tubing and tie
Same with water just
dry each tube and weigh for mass , record
place both in separate beakers with water
leave for 15-30 mins
remove, dry and measure weight
record fullness

start mass minus final mass - change in turgidity

Question 28

result of experiment

Answer 28

sucrose soln will have gained mass/ filled with water
water show no change

Question 29

animal hypotonic

Answer 29

haemolysis

Question 30

animal hypertonic

Answer 30

crenation

Question 31

plant hypotonic

Answer 31

turgid

Question 32

plant hypertonic

Answer 32

PLASMOLOYSED