1. Lesson 2.1
Cell structure and
function
Disediakan oleh:
NUR SUHAIDAH SUKOR
SMK SANDAKAN, SABAH

2. Introduction
Cell Theory
1. All organisms are composed of cells.
2. Cells are the smallest living things.
3. Cells arise only from pre-existing cells.
All cells have certain structures in common.
1. genetic material – in a nucleoid or nucleus
2. cytoplasm – a semifluid matrix
3. plasma membrane – a phospholipid bilayer

3. Animal Cells
3

4. Plant Cells
4

5. Nucleus
 Spherical
 stores the genetic
material. DNA is
organized with proteins
to form chromatin.
 Func: controls all
activities of cell.

6. Rough endoplasmic reticulum (RER)
 Membranes that create a
network of channels throughout
the cytoplasm
 Attachment of ribosomes to the
membrane gives a rough
appearance.
 Synthesis of proteins to be
secreted, sent to lysosomes or
plasma membrane
6

7. Smooth endoplasmic reticulum (SER)
 Relatively few
ribosomes
attached.
 Functions:
-synthesis of
membrane lipids
-detoxification of
drugs
7

8. RER & SER
8

9. Golgi Apparatus
 Flattened stacks of
interconnected
membranes.
 Packaging and
distribution of materials
to different parts of the
cell.
 Lysosome are formed
through budding of
vesicles.
9

10. Golgi apparatus
10

11. Lysosomes
-membrane bound vesicles
-containing digestive enzymes to break down
macromolecules
-destroy cells or foreign matter that the cell
has engulfed by phagocytosis
11

12. Lysosomes
12

13. Vacuoles
 spherical or oval shaped
filled with fluid.
 cell sap contains sugar,
salts, amino acid and waste
substances.
 bounded by semi-
permeable membrane
called tonoplast.
There are different types
of vacuoles:
-contractile vacuole
-food vacuole
13

14. Mitochondria
Mitochondria
-cylindrical shape
-two layers of membrane (inner membrane is
folded)
Func –site for cellular respiration.
-oxidise glucose to release energy in the
form of ATP.
14

15. Mitochondria
15

16. Chloroplasts
Chloroplasts
-Disc shaped organelle bounded by two
membranes.
-grana are stacks in the stroma
-granum contain chlorophyl
16

17. Chloroplasts
17

18. Cell wall
Structure
-rigid outer layer of plant cell
-made of cellulose
-permeable
Func –mantains the shape of plant cell
-protects the cell from brusting
-give support to the cell

19. Cytoplasma
Structure –jelly like medium
Func –place for biochemical reactions
Centrioles
Structure –small cylindrical structures
Func –form spindle fibers
-synthesis cilia and flagella of
small organism.

20. Plasma Membrane
Structure
-thin, semi permeable membrane.
-consists of protein, phospholipids.
Function
-regulates and control the movement of
substances in and out of cell.

22. The density of certain organelles related to its
function
Types of cells Function Density of certain
organelles
Sperm cell To swim towards Mitochondria need to
fallopian tube to fertilise produce energy
the ovum
Flight muscles For movement Mitochondria
insect and bird
Cells in meristem For growth, produce new mitochondria
cells
Palisade mesophyll cells photosynthesis Chloroplast
Liver cells Detoxification of drugs Smooth endoplasmic
reticulum
Pancreatic cells Produce enzymes Rough endoplasmic
reticulum, golgi