movement of substances in and out of cells

Question 1

diffusion is

Answer 1

the moving of particles from an area of high concentration to an area of low concentration

Question 2

osmosis

Answer 2

the moving of water particles through a semi permeable membrane from an area of high solute concentration to an area of low solute concentration

Question 3

active transport

Answer 3

the movement of particles from an area of low concentration to an area of high concentration using energy released during respiration

Question 4

is the cell membrane permabeable

Answer 4

it is partially permeable

Question 5

in living organisms does diffusion happen and through what

Answer 5

yes, the cell membrane

Question 6

diffusion allows living organisms to : (3)

Answer 6

• gain nutrients in the digestive system
• gain oxygen in the lungs
• remove waste products in the lungs and kidney

Question 7

osmosis is the ____ of water

Answer 7

diffusion

Question 8

in osmosis, water moves ___ concentration gradient

Answer 8

down

Question 9

partially permeable membranes prevent

Answer 9

the movement of larger molecules but allow the movement of smaller permeables

Question 10

osmosis an have a severe effect in animal cells because

Answer 10

there is no cell wall

Question 11

in animal cells, osmosis can lead them to become :

Answer 11

crenated ( dehydrated)

lysis ( bursting because of too much water)

Question 12

in plant cells, there is a cell wall so it prevents them from ( due to osmosis)

Answer 12

bursting

Question 13

can plant cells become shrivelled due to osmosis

Answer 13

yes

Question 14

what is a turgid cell (plant cells)

Answer 14

when in osmosis, the cell gains water, and the membrane pushes against the cell wall, making it turgid

Question 15

turgid cells provide (2)

Answer 15

structural support
and prevent wilting ( loss of support)

Question 16

is energy needed for active transport, why

Answer 16

yes because particles are being moved against a concentration gradient

Question 17

what energy does active transport use

Answer 17

energy from cellular respiration

Question 18

is active transport an active or passive process

Answer 18

active

Question 19

example of active transport

Answer 19

absorption of mineral ions from the soil into the root of hair cells of plants

Question 20

the bigger the cell, the smaller its surface to area volume ratio so the rate of diffusion

Answer 20

decreases

Question 21

many cells that are adapted for diffusion have

Answer 21

• large surface area

Question 22

example of cell adaptations for diffusion

Answer 22

• small intestine has villi and is folded highly so as to have a high surface area

Question 23

the smaller the distance molecules need to travel the ____ transport will occur

Answer 23

faster

Question 24

why do alveoli have cells that are one cell thick

Answer 24

to ensure the rate of diffusion across them is as fast as possible

Question 25

factors that affect diffusion (4)

Answer 25

surface area
temperature
distance
pH

Question 26

the higher the temperature ( diffusion) the ____ the molecules will move because ___

Answer 26

faster
they have more kinetic energy, so there are more collisions against the cell membrane

Question 27

the bigger the difference in concentration on wither side of the membrane, the ___ the movement across it will happen

why

Answer 27

faster

because on the side with the higher concentration, more random collisions against the membrane will occur

Question 28

PRACTICAL- factors that affect diffusion, surface area to volume ratio

Answer 28

you need three cubes of jelly with phaenofaelin indicator, one of 1cm², one of 2cm² and one of 3cm². The cubed will start off being pink

put one cube at a time in some acid and time how long it takes for each one to become colourless

work out surface area to volume ratio of each cube by doing surface are / volume

Question 29

Practical investigating factors that affect osmosis

Answer 29

• use a cork borer, a ruler and a knife to cut 5 equally sliced potato pieces (without skin)
• blot the cylinders using paper towels to remove excess water
• record mass of each one
• then add each one to a different salt solution ( ranging from 0.0moles to 1mole)
• leave them for 15 minutes
  then take them out and blot them again
• record final mass

calculate mass change

Question 30

PRACTICAL- factors that affect diffusion, surface area to volume ratio- RESULTS?

Answer 30

you will find that the bigger cubes have a smaller surface area to volume ratio and so they will take longer to get rid of their colour.

The smallest cube will become colourless quickest as it has the largest surface area to volume ratio.

Question 31

Practical investigating factors that affect osmosis RESULTS?

Answer 31

The ones in purer water ( so in 0moles) will gain more mass as more water will have moved in by osmosis

the ones in not pure water ( 1mole) will have lost mass as water will have left by osmosis