Transport : diffusion osmosis + active transport

Question 1

Diffusion

Answer 1

a net movement of particles through a partially permeable membrane from an area of higher concentration to an area of lower concentration

Question 2

Diffusion must occur within

Answer 2

a gas / dissolved substance

Question 3

Net movement

Answer 3

movement of all particles

Question 4

when molecules are left alone..

Answer 4

they move randomly

Question 5

diffusion is a __________ process
because it doesn’t require…

Answer 5

passive
energy from the cell, it is random movement of molecules

Question 6

partially permeable

Answer 6

only lets through smaller molecules such as water

Question 7

3 factors that affect the rate of diffusion

Answer 7

concentration gradient
temperature
surface area

Question 8

how does the concentration gradient affect diffusion

Answer 8

larger concentration gradient + higher rate of diffusion)

Question 9

how does temperature affect diffusion

Answer 9

higher temperature gives particles more energy to move faster

higher temp –> high rate of diffusion

Question 10

how does surface area affect diffusion

Answer 10

large surface area = more particles can fit around surface

large surface area –> higher rate of diffusion

Question 11

osmosis

Answer 11

the net movement of water molecules through a partially permeable membrane from an area of higher water concentration to an area of lower water concentration

Question 12

water concentration

Answer 12

amount of water compared to other molecules , like sugars and salts, dissolved in water

Question 13

hypotonic

Answer 13

lower concentration of solutes than inside the cell

Question 14

hypertonic

Answer 14

higher concentration of solutes than inside the cell

Question 15

isotonic

Answer 15

concentration of solutes is equal inside and outside cell

Question 16

hypotonic red blood cell

Answer 16

cell bursts because excesses water is being diffused

osmotic lysis

Question 17

isotonic red blood cell

Answer 17

normal
equal movement of water in and out

Question 18

hypertonic red blood cell

Answer 18

cell shrivels because of loss of water

crentation

Question 19

hypotonic root hair cell

Answer 19

normal
water enters cell

turgid

Question 20

isotonic root hair cell

Answer 20

becomes soft and loose

flaccid

Question 21

hypertonic root hair cell

Answer 21

cell membrane pulls away from wall, cell loses water

plasmolyzed

Question 22

a solution with a high water conc

Answer 22

dilute

Question 23

a solution with a low water conc

Answer 23

concentrated

Question 24

why can single celled organisms rely only on simple diffusion

Answer 24

they have a large surface area to volume ratio. lots of surface area to diffuse across and not too much volume to travel through

Question 25

why can large multi cellular organisms not just rely on simple diffusion

Answer 25

small surface area to volume ratio they have several layers of cells between the center and the environment, useful substances take longer to diffuse in and out

Question 26

what do large multi cellular organisms use instead of simple diffusion

Answer 26

transport systems of tubes and vessels (eg circulatory system)

Question 27

name a hazard risk and mitigation attempt in the osmosis potato rqp

Answer 27

scalpel, cutting skin, cut away from potato cork borer, injuring hand, cut potatoes on ceramic tile

Question 28

independent dependant and control variable in osmosis potato rqp

Answer 28

- conc of sucrose solutions - change in mass of potato cylinders - time each cylinder is left in sucrose solution

Question 29

why did the mass of the potato increase in distilled water

Answer 29

the water conc was higher outside the potato cell, therefore water moves into the potato through osmosis

Question 30

why did the mass of the potato decrease in solutions with 0.2-1m solutions

Answer 30

the water conc was lower outside the potato cell, so water moves out of the potato

Question 31

active transport

Answer 31

movement of particles across a partially permeable membrane against the concentration gradient (from low conc to high) requiring energy from cellular aerobic respiration

Question 32

active transport is a _______ process

Answer 32

active

Question 33

what proteins are needed in active transport

Answer 33

carrier proteins, they pick up specific molecules and carry them against the concentration gradient

Question 34

how does the villi use diffusion and active transport to get nutrients into the blood

Answer 34

diffusion is used until equilibrium is achieved . after this glucose moves from low conc (small intestine) to high conc (blood) through active transport. this ensures all nutrients are absorbed from your food

Question 35

examples of active transport

Answer 35

kidney reabsorbs sodium ions from urine thyroid gland takes in iodine for production of hormones

Question 36

definition of an exchange surface

Answer 36

a surface that is adapted to maximize the efficiency of gas and solute exchange

Question 37

adaptations of exchange surfaces

Answer 37

- large surface area for diffusion to occur - exchange surfaces usually very thin (short distance of travel) -permeable to the substance that needs to be exchanged

Question 38

name 4 exchange surfaces in plants and humans

Answer 38

alveoli villi leaves root hair cell

Question 39

what features do the villi have that help with diffusion

Answer 39

-good blood supply maintains conc gradient -thin walls for short diffusion -large surface area to volume ratio

Question 40

features alveoli have to help with diffusion

Answer 40

a good blood supply maintains conc gradient a layer of moisture helps gases dissolve large surface area to volume ratio

Question 41

why might the mass of the potato not change

Answer 41

the partially permeable membrane became damaged

Question 42

how are gills of a fish adapted to diffusion

Answer 42

- divided into thin layers of tissue forming a large surface area for diffusion -continual flow of water maintains a concentration gradient

Question 43

how are leaves adapted for diffusion

Answer 43

They are thin which gives a short diffusion distance They are flat which provides a large surface area to volume ratio They have many stomata which allow movement of gases in and out of the air spaces by diffusion

Question 44

how is the root hair cell adapted to maximize gas exchange

Answer 44

- large surface area to volume ratio - water stored in vacuole to maintain conc gradient - lots of mitochondria for gas exchange - thin exchange surface to shorten diffusion distance

Question 45

How does light affect transpiration

Answer 45

Increases because stomata opens wider to let in more co2, therefore more water evaporated through stomata

Question 46

How does temperature affect transpiration

Answer 46

Evaporation faster in high temperature

Question 47

How does wind affect transpiration

Answer 47

Faster because water vapor is removed quickly speeding up diffusion of water vapor increasing conc gradient

Question 48

How does humidity affect transpiration

Answer 48

Slower because leaf is surrounded by moisture

Question 50

What type of day has best transpiration

Answer 50

Sunny warm windy

Question 51

How does stomata open

Answer 51

Guard cells fill with water by osmosis Thicker inner wall does not stretch as much as thinner outer wall Results in guard cells bending banana shaped

Question 52

When does stomata open and close

Answer 52

Open in day closed at night

Question 53

Is there a difference in number of stomata on top than bottom

Answer 53

There are less stomata on top because there will be more exposure to sunlight, higher rate of transpiration, more volume water lost