CHAPTER 2 :
CELL STRUCTURE &
CELL ORGANISATION
2.1 Cell Structure & Function
2.2 Cell Organisation
2.1

CELL STRUCTURE
& FUNCTION
Learning Outcomes :

1.
2.
3.
4.
5.

Draw & label an animal cell and a plant cell
Identify the cellular components of an animal
cell & a plant cell
State the functions of the cellular components
in an animal and a plant cell
Compare & contrast an animal cell with a plant
cell
Relate the density of certain organelles with
the functions of specific cells.
HISTORY
 Robert

Hooke (1665) was first
discovered the cell structure of
plant
 He examined fine slices of cork
with a primitive microscope
 He saw many ‘box-like’ structures ,
then he called ‘cells’, from Latin for
‘little rooms’.
THE CELL THEORY
(Schleiden M & Schwann T)
All living organisms are made up of one or
more cells
 New cells are formed by the division of
pre-existing cells
 Cells contain genetic material of an
organism which is passed from the parent
cells to daughter cells
 Cells are the basic unit of structure &
function in living things

 ORGANELLES

 specialised
structures which are each
surrounded by its own membrane &
perform specific function
PLASMA
MEMBRANE
Thin, semi-permeable
 Made of protein, lipid
 Controls the
movement of
substances in and out
of the cell
 Non-organelle

CYTOPLASM









Jelly-like substance
that contains water &
mineral salts
Contains organelles
and food such as
carbohydrates
(glucose)
Medium for metabolic
reactions
Supplies the
substances required
by organelles
Non-organelle
CELL WALL
Thick layer outside
the plasma
membrane
 Made up of cellulose,
fully permeable
 Maintains the shape
of the plant cells
 Provides mechanical
support
 Non-organelle

NUCLEUS






Spherical shape with
double membrane
Contains nucleolus,
chromosomes,
nucleoplasm & nuclear
membrane
Controls & regulates
all the activities of cell
Contain the heredity
factors responsible for
the traits
RIBOSOME
Small particles
consisting of RNA
 Exists freely in the
cytoplasm or on the
surface of the
endoplasmic
reticulum
 Synthesis of protein

ENDOPLASMIC RETICULUM








A system of membraneenclosed tubules closely
packed together and
continuous with the nuclear
membrane
RER has ribosome, SER
does not have
Transport system for
protein & lipids within the
cell
RER transport protein to
other part of cell
SER stimulates the
synthesis of lipids &
cholesterol & transport
within the cell









GOLGI APPARATUS
Vacuolar region surrounded
by a complex meshwork of
vesicles budding off at its end
Received protein & lipids from
ER & modify them to form
specific secretion such as
enzymes & hormones
Pack the secretions formed
into secreting vesicles &
transport them to plasma
membrane to be secreted
Controls the secretory activity
of cells
Formation of lysosomes
VACUOLE
Filled with cell sap,
surrounded by semipermeable
membrane called the
tonoplast
 Contain water, sugar
& dissolved minerals
 Maintain turgidity of
cells in plants

MITOCHONDR
IA






Rod-shape with a
double membrane
Outer membrane is
smooth, inner
membrane is folded to
form cristae
Known as ‘powerhouse’ of the cell
Releases energy as it
is the site for aerobic
respiration
CHLOROPLAST







Disc-shape organelle
with a double
membrane
Consist of an orderly
arrangement of grana
within the stroma.
Granum contains
chlorophyll
Site of photosynthesis
Trapped light energy
and change it into
chemical energy
LYSOSOMES






Membrane-bound
vesicles found in animal
cells
Contain enzymes which
control breakdown of
protein & lipids
Contain enzymes that
digest aged or defective
cell components or
materials taken in by the
cell from its
environments such as
food particles or
bacteria.
CENTRIOLES


A pair of
small
cylindrical
structures
(microtubules
)



Form spindle
fibre for cell
COMPARE & CONTRAST
ANIMAL CELL
A

PLANT CELL

plasma membrane surrounding the
cytoplasm

Both
Both

SIMILARITIES

contain nucleus & cytoplasm

contain organelles such as mitochondria,
ER, Golgi apparatus & ribosomes
ANIMAL CELL

DIFFERENCES

PLANT CELL

Smaller than plant cell

SIZE

Larger than animal cell

Irregular shape

SHAPE

Often regular in shape

Absent

CELL WALL

Present

Absent

CHLOROPLAST

Present

No large vacuoles. If
present, small &
numerous.

VACUOLES

Large central vacuole
filled with cell sap

In a form of glycogen in
liver & muscle tissues

FOOD STORAGE

In a form of starch

Present

CENTRIOLES

Absent

Some animal cell have
cilia or flagella

CILIA & FLAGELLA

Absent
RELATIONSHIP BETWEEN THE
STRUCTURE OF AN ANIMAL CELL & A
PLANT CELL


The number of specific organelles in a cell
varies on the type of cell and its function.



Active cell  many mitochondria to provide
enough energy for its activities. Eg. : sperm
cells, flight muscle cell (insects & birds)



Cell in meristems of plant shoot & root



Green plants  more chloroplasts to carry out
photosynthesis such as palisade mesophyll cells
and spongy mesophyll cells, also guard cells.
EXERCISE 2.1
1.
2.

What are the organelle structures of a
cell?
What are the functions of each structure
describe above?
2.1   cell function by SAS

2.1 cell function by SAS

  • 1.
    CHAPTER 2 : CELLSTRUCTURE & CELL ORGANISATION 2.1 Cell Structure & Function 2.2 Cell Organisation
  • 2.
    2.1 CELL STRUCTURE & FUNCTION LearningOutcomes : 1. 2. 3. 4. 5. Draw & label an animal cell and a plant cell Identify the cellular components of an animal cell & a plant cell State the functions of the cellular components in an animal and a plant cell Compare & contrast an animal cell with a plant cell Relate the density of certain organelles with the functions of specific cells.
  • 4.
    HISTORY  Robert Hooke (1665)was first discovered the cell structure of plant  He examined fine slices of cork with a primitive microscope  He saw many ‘box-like’ structures , then he called ‘cells’, from Latin for ‘little rooms’.
  • 5.
    THE CELL THEORY (SchleidenM & Schwann T) All living organisms are made up of one or more cells  New cells are formed by the division of pre-existing cells  Cells contain genetic material of an organism which is passed from the parent cells to daughter cells  Cells are the basic unit of structure & function in living things 
  • 8.
     ORGANELLES  specialised structureswhich are each surrounded by its own membrane & perform specific function
  • 9.
    PLASMA MEMBRANE Thin, semi-permeable  Madeof protein, lipid  Controls the movement of substances in and out of the cell  Non-organelle 
  • 10.
    CYTOPLASM      Jelly-like substance that containswater & mineral salts Contains organelles and food such as carbohydrates (glucose) Medium for metabolic reactions Supplies the substances required by organelles Non-organelle
  • 11.
    CELL WALL Thick layeroutside the plasma membrane  Made up of cellulose, fully permeable  Maintains the shape of the plant cells  Provides mechanical support  Non-organelle 
  • 12.
    NUCLEUS     Spherical shape with doublemembrane Contains nucleolus, chromosomes, nucleoplasm & nuclear membrane Controls & regulates all the activities of cell Contain the heredity factors responsible for the traits
  • 13.
    RIBOSOME Small particles consisting ofRNA  Exists freely in the cytoplasm or on the surface of the endoplasmic reticulum  Synthesis of protein 
  • 14.
    ENDOPLASMIC RETICULUM      A systemof membraneenclosed tubules closely packed together and continuous with the nuclear membrane RER has ribosome, SER does not have Transport system for protein & lipids within the cell RER transport protein to other part of cell SER stimulates the synthesis of lipids & cholesterol & transport within the cell
  • 16.
         GOLGI APPARATUS Vacuolar regionsurrounded by a complex meshwork of vesicles budding off at its end Received protein & lipids from ER & modify them to form specific secretion such as enzymes & hormones Pack the secretions formed into secreting vesicles & transport them to plasma membrane to be secreted Controls the secretory activity of cells Formation of lysosomes
  • 18.
    VACUOLE Filled with cellsap, surrounded by semipermeable membrane called the tonoplast  Contain water, sugar & dissolved minerals  Maintain turgidity of cells in plants 
  • 19.
    MITOCHONDR IA     Rod-shape with a doublemembrane Outer membrane is smooth, inner membrane is folded to form cristae Known as ‘powerhouse’ of the cell Releases energy as it is the site for aerobic respiration
  • 21.
    CHLOROPLAST     Disc-shape organelle with adouble membrane Consist of an orderly arrangement of grana within the stroma. Granum contains chlorophyll Site of photosynthesis Trapped light energy and change it into chemical energy
  • 22.
    LYSOSOMES    Membrane-bound vesicles found inanimal cells Contain enzymes which control breakdown of protein & lipids Contain enzymes that digest aged or defective cell components or materials taken in by the cell from its environments such as food particles or bacteria.
  • 23.
  • 24.
    COMPARE & CONTRAST ANIMALCELL A PLANT CELL plasma membrane surrounding the cytoplasm Both Both SIMILARITIES contain nucleus & cytoplasm contain organelles such as mitochondria, ER, Golgi apparatus & ribosomes
  • 25.
    ANIMAL CELL DIFFERENCES PLANT CELL Smallerthan plant cell SIZE Larger than animal cell Irregular shape SHAPE Often regular in shape Absent CELL WALL Present Absent CHLOROPLAST Present No large vacuoles. If present, small & numerous. VACUOLES Large central vacuole filled with cell sap In a form of glycogen in liver & muscle tissues FOOD STORAGE In a form of starch Present CENTRIOLES Absent Some animal cell have cilia or flagella CILIA & FLAGELLA Absent
  • 26.
    RELATIONSHIP BETWEEN THE STRUCTUREOF AN ANIMAL CELL & A PLANT CELL
  • 27.
     The number ofspecific organelles in a cell varies on the type of cell and its function.  Active cell  many mitochondria to provide enough energy for its activities. Eg. : sperm cells, flight muscle cell (insects & birds)  Cell in meristems of plant shoot & root  Green plants  more chloroplasts to carry out photosynthesis such as palisade mesophyll cells and spongy mesophyll cells, also guard cells.
  • 28.
    EXERCISE 2.1 1. 2. What arethe organelle structures of a cell? What are the functions of each structure describe above?