2. Need for movement of substances
across plasma membrane
Semua bahan yang
diperlukan oleh sel dan
hasil buangannya perlu
diangkut merentasi
membran plasma sel.
membran plasma adalah
SEPARA TELAP, yang
mana ia hanya
membenarkan bahan
tertentu bergerak
merentasinya.
3. Membran Plasma
struktur membran plasma terdiri daripada dwi-
lapisan fosfolipid dan molekul protein.
Dwilapisan fosfolipid dan molekul protein
membentuk struktur yang dinamik dan bersifat
bendalir.
Molekul protein terapung secara bebas dalam
dwilapisan fosfolipid.
4.
5. Setiap molekul
fosfolipid terdiri
daripada
kepala hidrofilik
(tertarik kepada air)
ekor hidrofobik
(menjauhi air).
8. SIFAT SEPARA TELAP
Molekul protein adalah protein pengangkut
seperti
protein liang
protein pembawa.
Bahan yang boleh bergerak merentasi dwilapisan
fosfolipid melalui resapan ringkas adalah
molekul kecil tidak bercas seperti air, oksigen,
karbon dioksida
molekul larut lemak seperti asid lemak, gliserol,
vitamin A, D, E dan K.
9. Molekul berkutub yang lebih besar seperti
glukosa dan asid amino serta ion bercas yang
kecil TIDAK BOLEH bergerak merentasi
dwilapisan fosfolipid.
Bahan ini merentasi membran plasma dengan
bantuan protein pembawa melalui resapan
berbantu.
Glukosa dan asid amino diangkut merentasi
membran plasma dengan bantuan protein
pembawa.
Ion mineral kecil yang bereas melalui membran
plasma dengan bantuan protein liang.
Molekul besar seperti sukrosa, protein dan kanji
tidak boleh bergerak merentasi membran plasma.
11. Pengangkutan pasif
• Menuruni kecerunan kepekatan (dr kaw
kepekatan tinggi ke rendah)
• Tidak perlu tenaga
• Bahan boleh merentasi dgn dua cara
– Lapisan fosfolipid
– Protein liang
– Protein pembawa
• Bahan boleh bergerak secara bebas tanpa
menggunakan tenaga
• Reapan ringkas
• Osmosis
• Resapan berbantu
12. Resapan ringkas
• Molekul MERESAP
merentas membran
plasma
• Menuruni kecerunan
kepekatan
• Sehingga keseimbangan
tercapai
• Cth:
– Saiz kecil tidak berpolar :
O2/CO2
– Molekul larut lemak: fatty
acid, glyserol and also
vitamin A, D, E and K.
14. Osmosis
Molekul air MERESAP
Menuruni kecerunan
kepekatan bahan
Merentasi membran
plasma
Sehingga tecapai
keseimbangan
15. Resapan berbantu
• Bahan MERESAP merentas membran plasma
• Bantuan
• Protein liang – molekul kecil bercas : ion mineral
• Protein pembawa – molekul besar : glukosa, asid
amino
• Menuruni kecerunan kepekatan
• Cth: pengangkutan bahan hasil pencernaan
karbohidrat kepada glukosa. Glukosa meresap
masuk ke dalam vilus di usus kecil
18. Simple diffusion Osmosis Facilitated diffusion
Through lipid bilayer Through carrier
protein and channel
protein
Plant cell Animal cell Application
Isotonic solution
Hypotonic solution
Hypertonic solution
Shape and
size
maintained
Shape and
size
maintained
HaemolysisCell is turgid
Crenation
Cell is flassid
(Plasmolysis)
Wilting in plants
Preservation of food
PASSIVE TRANSPORT
20. PENGANGKUTAN AKTIF
Bahan meresap merentasi membran plasma
Melawan kecerunan kepekatan
Menggunakan TENAGA ATP
Bantuan protein pembawa
Cth :
Pam ion natrium kalium
Pengangkutan ion mineral oleh sel akar
24. 3.2 Movement of Substances
across the Plasma Membrane
Explain what hypotonic, hypertonic and isotonic solution are
Explain the effect of hypotonic, hypertonic and isotonic solution
on plant and animal cell
Explain plasmolysis, deplasmolysis, haemolysis, and crenation.
Explain the phenomenon of wilting in plants using examples
Explain the preservation of food using examples
25. Explain what hypotonic, hypertonic and isotonic
solution are
Isotonic solution:
A solution in which the solute concentration in the cell is equal to the
concentration of solute outside the cell
Water diffuses into and out of the cell at equal rate
Thus, there is no net movement of water across the plasma
membrane
Hypotonic solution:
A solution in which the solute concentration in the cell is lower than
the concentration of solute outside the cell
Thus, there is a net movement of water from the outside into the cell.
Hypertonic solution:
A solution in which the solute concentration in the cell is higher to
the concentration of solute outside the cell
Thus, there is a net movement of water from the inside to the outside
of the cell
26. PLANT CELLS
1. When a plant cell is
immersed in hypotonic
solution, water molecules
diffuse into the cell by
osmosis
2. The vacuole gains water,
expands and exerts
pressure outwards on the
cell wall
3. The pressure is called
turgor pressure and causes
the plant cell to become
turgid
27. • When plant cell placed in
hypertonic solution,
water molecules diffuses
out of the cell by osmosis
• Water loss from vacuole
and cytoplasm
• The vacuole shrinks and
become smaller. The cell
becomes flaccid and
causes plant to wilt
• This process called
plasmolysis
28. ANIMAL CELLS
1. When a animal cell is
immersed in hypotonic
solution, water molecules
diffuse into the cell by
osmosis
2. Water enters the cell,
causing it to swell up and
eventually burst.
3. This busting of red blood
cells is known as
haemolysis
29. • When animal cell placed
in hypertonic solution,
water molecules diffuses
out of the cell by osmosis
• Water loss from the cell
and cause the cell to
shrink.
• The red blood cells have
undergone crenation
30. • If the animal cell or plant
cell is immersed in an
isotonic solution, there is
no net movement of
water across the plasma
membrane
• Water flows across the
membrane at same rate
in both direction
• The cell’s volume and
shape remain constant
31. Explain the phenomenon of wilting in plants using examples
Wilting of plant when
given too much fertilizer.
32. Explanation
Fertilisers will dissolve in the soil and caused the soil
water to be hypertonic to the root cells of plant
Water diffuse out from the root to their surrounding
by osmosis
Plasmolysis occur and plant cell become flaccid,
cause the plant wilt.
33. Explain the preservation of food using examples
Preserved food such as salted fish and pickled
cucumber.
34. 3.3 Appreciating the Movement of
Substances across the Plasma
Membrane
Explain the necessity for the movement of
substances across plasma membrane which occurs
in the continuous and controlled manner for the
survival of the cell.
35. The movement of substances
across the plasma
membrane occurs in a
continuous and controlled
manner for survival of a cell.
As a gate keeper, plasma
membrane will regulate
what goes in and out of the
cell
So that, it is essential for us
to take care of our food and
water intake everyday to
prevent the body from
getting dehydrated.