2d- movement of particles in cells

Question 1

what is concentration

Answer 1

no. of particles in a given area (1cm^3) ,
↑ con = ↑particles

Question 2

what is osmosis

Answer 2

movement of water molecules from hc (dilute solution) –> lc (concentrated solution) throyugh a semi-partial membrane.

Question 3

why is diffusion a passive process?

Answer 3

no energy rq b/c it goes w concentraition gradient

Question 4

what happens at the end of diffusion?

Answer 4

equilibrium

Question 5

what is diffusion

Answer 5

movement of particles from a region of hc –> lc, down a concentration gradient.

passive process

Question 6

what is active transport

Answer 6

movement of particles against a concentration gradient, lc –> hc

active process (energy req.)

req. energy from respiration and protein pumps, located in cell memb.

Question 7

what is diffusuin important for (3)

Answer 7

• getting raw materials from respiration

e.g.
O2 diffused from alveoli (lungs) –> blood stream

• removing watse products (from respiration)

e.g
CO2 diffused into lungs to exhale

• photosynthesis in plants

Question 8

what is osmosis importnat for?

Answer 8

plant support

Question 9

3 types of plant cells support from osmosis + defonitio

Answer 9

turgid –> full of water, hwc, from out –> in

flaccid cells –> low water, lwc from in. –> out

plasmolysed –> dead cell

Question 10

affecting factors of dfiffusion and osmosis (rodo) (direct proportion) (3)

Answer 10

temp, concentration diff, surface area

Question 11

how does temp increase rodo?

Answer 11

temp ↑,
kinetic energy of particles ↑
= quicker to move from hc –> lc
= rodo ↑

Question 12

how does concentration diff increase rodo

Answer 12

concentration diff ↑
= steeper gradient
= quicker it is to reach the region of lc
= rodo ↑

(sorta like an emergency, if hc of O2 in blood but not in lungs, = emergency and needs to reach equillibruium ASAP)

Question 13

how does surface area increase rodo

Answer 13

surface area ↑
= more membrane of a cell
= substance has more space to enter cell
= amnt of sub diffusing into cell ↑
= rodo ↑

Question 14

affecting factors of diffusiion and osmosis (inverse proportion) (1)

Answer 14

distance path

Question 15

hwo does distance path affect rodo

Answer 15

distance path ꜜ
= less space for particle to travel,
= faster to get there
= rodo ↑

Question 16

example of active transport

Answer 16

how minerals get into hair root cells

Question 17

example of diffusion

Answer 17

how O2 leaves a leaf

Question 18

example of osmosis

Answer 18

how water keeps plant cells turgid

Question 19

method for osmosis in potato slices experiment?

Answer 19

1. cut potato tissue (SAME)
2. 10ml of each concentration sucrose solution in test tubes
3. same length cut (3cm)
4. measure mass of disc b4
5. add discs into sucrose
6. wait, take them then measure their mass
7. calculate change in mass and mass percentage

Question 20

explain why the potato slices lose and gain mass in the experiment?

Answer 20

gain:
- water passes into cell membrane , through osmosis b/c
water in solution > water in potato
and hc –> lc

loss:
- water from potato passes into sucrose solution, through osmosis b/c
water in potato > water in solution
and hc –> lc,

water moves out, losing mass

Question 21

decribe the experiement, whats the acronym and what deos it stand for?

Answer 21

I –> independent varibale
D –> dependent variables
C (x2) –> controlled variable

O –> organism used
R –> repetition?
M–> measure, how
C–> calculate

Question 22

explain why cells are small using sa:v ratio

Answer 22

cells need to do diffusion and osmosis, the rate of diffusion increases with smaller objects, b/c smaller = higher sa:v