Summary AQA ALEVEL BIOLOGY NOTES ON OSMOSIS

Osmosis

|
→
from of
Osmosis is the movement of water an area
high
.
. water potential to an area of low water
potential
.




I membrane
'


a-
.
'
across a semi -
permeable .




"




demonised of
Only water has water potential OK7A
. '
.


pure a
.
•
,
.
-



/
water has water
Any dissolved
-
I
- .
.
-

solution with a
/
)
i -
I
'
I

potential L 0 kPa
-

I -
.
.


<



I solution )
.

i
"
-

The solute that is added ( i.e the more concentrated a the
-
, more ,
,
lower ( negative ) potential
'
more water .




H
0 H I
"
✓
t' ←
You cannot
-100hPa I I ions
-
o move
0Pa it H ti O t
CI without water
' -




High water Low water oft, t
'
o
Na
o
-
moving .




I /
potential
-
H
potential
H H
I
-
µ
0 H


Pure Water 4=0 kPa 4 -2004Pa Concentrated solution 4 =
-5004Pa
Dilute solution =



I 1 a 0
0 0 00 8 O O o
080 I o o
o o I o o
o
o
o oo § 0
• o
O O o p p 0 00
°
I O
O o
I
8 o or o o
o
O u 00 o
0 0
° ° 0
o 1 °
I o 0
0
000 0

°
0 0 000 000
• a
1 O
o
0
0 I 0
0000
0
00 000 a 00
°
I
0 I ° 0000 0
O O
O o O O
I
o I
°
go
0
000 0 80 0
⑨ 00
°
0 1 I 0
000 0
go
\ I
- -
water diffuses water diffuses
from -200Pa to
from 0hPa to -2004Pa
-5004Pa
I 1

Example :
"
Lumen of 1 '



Epithelial cell I
-


Bloodstream
I 1
digestive system 1 I

1 I
I
\
Mid root hair cell Top root hair cell
.



Root hair cell I
-
- -
-


1
I




Difference in water Potential

,1 11 TITLE -l -←
It


Iso tonic solution "
solution of equal water
potential to cell (
strength )
• "
a a same

Hyper tonic solution solution of lower
high strength 's
"

potential 1
✓
-
a water than a cell
= =


Hypotonia of higher strength )
''

potential
"
•
solution a
solution water than a cell L low
= =




Hyper tonic Is tonic Hypotonia
4 of
extenuation
solution
compared
more
negative Equal less
negative
to
cell
No Bursts
state shrinks change swells &




①
Holy
%




①
HL0
)




Cremation esneise.fi?Iysscaisneo
hae.no/ysisin0smoIysisL
( shrinks)
red blood cells


( Bursts )