1. 1 11
Chapter 2: Cells
Chapter 2- Cells

2. 2
The discovery of cells
Robert Hooke
Anton van Leeuwenhoek
Schleiden & Schwann (Cell
Theory)

3. 3 33
TheThe
animalanimal
cell (3-cell (3-
D)D)
Nucleus
Vacuoles
Plasma Membrane
Mitochondrion
Nucleolus
Cytoplasm
Golgi apparatus
Rough
endoplasmic
reticulum

4. 4
Label the parts of an animal
cell.

5. 5 55
TheThe
plantplant
cellcell
(3-D)(3-D)
Cell wall
Plasma Membrane
Central vacuole
Chloroplasts
Mitochondrion
Nucleus
Cytoplasm
Nucleolus
Golgi apparatus
Rough
endoplasmic
reticulum
Smooth
endoplasmic
reticulum

6. 6
Label the parts of a plant cell.

7. 7 77
 C = Chloroplast
(next slide)
 ER =
Endoplasmic
Reticulum
 G = Granum
(next
slide)

M =
Mitochondrion
 S = Starch Grain
 T = Thylakoids
(next slide)
 V = Vacuole
 W = Cell Wall
Plant Cell – 22 500 X (electron micrographs)

8. 8
3-D structure of a chloroplast

9. 9 99
Organelle Structure Function
Nucleus Consists of:
Nucleoplasm
Nuclear envelope
Chromatin threads
One nucleolus or
more nucleoli
Controls the
activities of the
cell such as cell
growth & repair of
worn-out parts
 Essential for cell
division
Nuclear envelope
Separates the contents of the
nucleus from the rest of the
cytoplasm
Nucleoplasm
Dense material within the
nucleus
Chromatin threads
Network of long thread-like
structures
Condenses to become rod-like
chromosomes
Each thread is made up of proteins
and DNA
Nucleolus
Plays a part in the making of proteins

10. 10
Organelle Structure Function
Plasma
Membrane /
Cell surface
membrane
Partially-
permeable
membrane that
forms a boundary
between the
cytoplasm of the cell
and the outside.
Have pores (small
holes) on it
Regulate the
passage of
substances entering
and exiting the cell

11. 11
Organelle Structure Function
Cytoplasm Jelly-like
complex material
that contains all
the organelles of
a cell.
 Is the part of the
protoplasm
between the cell
surface
membrane and
nucleus.
 Part of the cell
where most cell
activities occur

12. 12
Organelle Structure Function
Mitochondria
(plural)
Mitochondrion
Contains many
folds to increase
surface area for
synthesis of
ATP molecules /
energy molecules
‘Power house’ of
the cell
During aerobic
respiration, energy
is released
ATP = Adenosine triphosphate

13. 13
Organelle Structure Function
Rough
Endoplasmic
Reticulum
(RER)
Ribosomes
attached on
RER
Ribosomes on it make
proteins that are enclosed
in vesicles transported to the
Golgi apparatus for
secretion out of the cell.
Smooth
Endoplasmic
Reticulum
(SER)
No ribosomes
attached.
Synthesizes fats and
steroids (eg. sex hormones)
Detoxifies harmful
substances

14. 14
Organelle Structure Function
Free
ribosomes
(a type of
proteins made
in the
nucleolus)
In theIn the
cytoplasmcytoplasm
Make proteins that areMake proteins that are
used within theused within the
cytoplasm of the cell.cytoplasm of the cell.

15. 15
Organelle Structure Function
Golgi Apparatus
(GA)
[Vesicle movement]
http://biologica.conco
rd.org/webtest1/Sho
ut3d_cell_6_1_00/v2
_frameset.htm
Consists of
flattened spaces
surrounded by
membranes
Vesicles seen
fusing with one
side of GA and
pinching off from
the opposite side
Stores and
modifies
substances /
proteins made by
the RER
Packages these
substances /
proteins in
vesicles for
secretion out of the
cell

16. 16
1. Vesicles transport substances within
the cell. Small vesicles containing
substances made by the ER are pinched
off from the ER.
How substances made by
the endoplasmic reticulum
enter the Golgi apparatus
and are finally secreted out
of the cell
rough endoplasmic
reticulum
vesicle
forming
Processes in the Golgi Apparatus

17. 17
1. Vesicles transport substances within
the cell. Small vesicles containing
substances made by the ER are pinched
off from the ER.
How substances made by
the endoplasmic reticulum
enter the Golgi apparatus
and are finally secreted out
of the cell
rough endoplasmic
reticulum
vesicle
formingvesicle
pinched off
Processes in the Golgi Apparatus

18. 18
1. Vesicles transport substances within
the cell. Small vesicles containing
substances made by the ER are pinched
off from the ER.
2. Vesicles then fuse with the Golgi
apparatus and release their contents
into the Golgi apparatus. The
substances made by the ER may be
modified inside the Golgi apparatus.
How substances made by
the endoplasmic reticulum
enter the Golgi apparatus
and are finally secreted out
of the cell
rough endoplasmic
reticulum
vesicle
forming
vesicle fusing with
Golgi apparatus
Golgi apparatus
vesicle
pinched off
Processes in the Golgi Apparatus

19. 19
1. Vesicles transport substances within
the cell. Small vesicles containing
substances made by the ER are
pinched off from the ER.
4. Secretory vesicles fuse
with the cell surface
membrane and their
contents are released outside
the cell.
How substances made by the
endoplasmic reticulum enter
the Golgi apparatus and are
finally secreted out of the cell
3. Secretory vesicles
containing these modified
substances are pinched off
from the Golgi apparatus.
They then move to fuse with
the cell surface membrane.
rough endoplasmic
reticulum
vesicle
forming
secretory vesicle
pinched off
substances released
outside the cell
secretory vesicle fuses
with cell surface
membrane
vesicle
pinched off
2. Vesicles then fuse with the Golgi
apparatus and release their contents
into the Golgi apparatus. The
substances made by the ER may be
modified inside the Golgi apparatus.
vesicle fusing with
Golgi apparatus
Golgi apparatus
Processes in the Golgi Apparatus

20. 20
Organelle Structure Function
Centrioles Consists of two
short cylinders,
facing right angles
at each other
organize the
assembly of
spindle
microtubules
during cell division.
In animal cells

21. 21
Organelle Structure Function
Vacuole Fluid filled
space bound
by a partially
permeable
membrane
Usually exists
temporarily
Stores dissolved
sugars, mineral ions
and other solutes.
In animal cells

22. 22
Organelle Structure Function
Vacuole Fluid filled spaceFluid filled space
surrounded by asurrounded by a
partiallypartially
membranemembrane
known asknown as
tonoplasttonoplast
contains cell sapcontains cell sap
such as nutrientssuch as nutrients
and mineral saltsand mineral salts
In plant cells

23. 23
Organelle Structure Function
Chloroplast Contains chlorophyll
(green pigment which
absorbs light energy for
photosynthesis).
In plant cells

24. 24
Organelle Structure Function
Cell wall Fully permeable
layer of non-living
material found outside
the plasma
membrane.
Contains cellulose
Gives plant cell a
fixed shape
Gives protection
from injury
In plant cells

25. 25 2525
Differences between animal
and plant cell
Animal Plant
Cell wall absent present
Chloroplasts absent present
Vacuoles small and many usually large and
central
Stores food as glycogen granules starch granules

26. 26 2626
Specialized cells
 Specialized cells are slightly different from typical cells in
that they have been modified and adapted to better carry
out certain functions.
 Some examples are
Red blood cell in mammals
Xylem cell in plants
Root hair cell in plants

27. 27
Specialised / Differentiated
cellsDifferentiation: A
process in which
the zygote
undergoes a change
from a simple to
complex structure.
(contains
DNA from
both parents)

28. 28
cell
membrane
Cytoplasm with a red
pigment protein called
haemoglobin. It carries
oxygen.

29. 29 2929
Red blood cells
Structure of RBC in relation
to its function?
Adaptation: Circular,
biconcave shape
Function: Increases
surface area to volume
ratio. Thus, oxygen diffuse
in and out at a faster rate.

30. 30 3030
Red blood cells
Structure of RBC in relation
to its function?
Adaptation: Nucleus is absent
Functions:
Carry more haemoglobin and hence more
oxygen .
It also enables them to fold easily to squeeze
through narrow capillaries.

31. 31 3131
Root hair
Functions
 Adapted for the absorption of water and
mineral salts from the soil.
 Anchor the plant firmly to the ground.
nucleus
Central vacuole
Plasma membrane
Cytoplasm
Cellulose cell wall

32. 32 3232
Structure of the root hair cell in relation
to its function
 Structure:Long and narrow protrusion
Function:Increases surface area to volume ratio
forabsorption of water and mineral salts.
 Structure:Large vacuole
Function:Increases the concentration of salts and
sugars.
Thus, higher rate of absorption of water.
Root hair cell

33. 333333
The Xylem VesselThe Xylem Vessel

34. 34 3434
Xylem cells
 Dead cells which have lost their nucleus
and cytoplasm
 Hollow and placed end-to-end to conduct
water and dissolved mineral salts from the
roots to the rest of the plant.
 Contain lignin, a woody substance that
increases the strength of the vessel. This
helps in the support of the plant.

35. 35 3535

36. 36
 Hollow long
vessel
 Narrow lumen
Xylem Vessel

37. 37
Young Xylem vessels
Matured
xylem
vessels

38. 383838
The Xylem Vessel
Functions
 To provide mechanical strength to plant body.
 To conduct water & mineral salts from root to all
parts of plant.
What is its adaptation to its function?
 Lignified cell wall for strength to support the
plant.
 Narrow lumen & hollow, long vessel for water
and mineral salts transport.

39. 39
Division of labour
Multi-cellular organism
 each cell types
specialises in
performing one
particular function
 the more highly
developed the organism
is, the greater is the
degree of division of
labour

40. 40
Division of labour
Advantage :
 Ensures smooth and
efficient functioning of
the organism.
 Different function can
be performed at the
same time.

41. 41
A group of cells work together to form a tissue.
intestinal epithelium (tissue) made
up of intestinal epithelial cells
epithelium in the trachea
(tissue) made up of epithelial
cells and gland cells
cartilage in the trachea
(tissue) made up of
connective tissue cells
epithelium in the lungs
(tissue) made up of
epithelial cells
connective tissue in the
lungs made up of
connective tissue cells
muscle cell
neurones
intestinal
epithelial cell
epithelial cell
gland cell
muscle tissue made
up of muscle cells
nervous tissue made up of
neurones (nerve cells)
connective
tissue cell
connective
tissue cell
epithelial
cell
Specialised Cells, Tissues, Organs & SystemsSpecialised Cells, Tissues, Organs & Systems

42. 42 4242
Different tissues combine to form an organ.
trachea
(organ)
lungs
(organs)
stomach
(organ)
intestine
(organ)
muscle tissue
cartilage (tissue)
muscle tissue connective tissue
nervous tissue
intestinal epithelium
(tissue)
epithelium (tissue)
epithelium (tissue)
Specialised Cells, Tissues, Organs & SystemsSpecialised Cells, Tissues, Organs & Systems

43. 43 4343
Several organs work together to make up an organ system.
lungs
(organs)
trachea
(organ)
intestine
(organ)
stomach
(organ)
digestive system
(organ system)
respiratory system
(organ system)
Specialised Cells, Tissues, Organs & SystemsSpecialised Cells, Tissues, Organs & Systems

44. 44 4444
human
(organism)
digestive system
(organ system)
respiratory system
(organ system)
Various organ systems work together to make up an organism.
Specialised Cells, Tissues, Organs & SystemsSpecialised Cells, Tissues, Organs & Systems