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Cell Structure and
Function
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All living things are made up of basic units
called cells.
Cells vary in shape, sizes and content
depending on their function.
A light microscopeis usually used to
help us observe microscopic cells.
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The living component of a cell is called
protoplasm.
Protoplasm = cytoplasm + nucleus
Protoplasm surrounded by plasma
membrane.
Plant cells have an outer boundary called
the cell wall.
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Animal cell
Plant cell
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Cell Parts and Structures
With electron microscopes, scientists are able to seethe cellular components of a cell in greater detail.
The cytoplasm contains structures called organelles.
Organelles perform specific function which enable the
cell to function as a unit of life.
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Animalcell
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P
lantcell
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Controls cellular
activities.
Nucleus membrane
controls inflow and
outflowof material to
and from nucleus
Nucleolus acts as site
of ribosome
construction. Chromosome carries
hereditary information.
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Acts as a mediumwhere biochemical
reactions and most
living processes
occur within the cell.
Provides the
organelles with
substances obtainedfrom external
environment.
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Separates the content
of the cell from its
external environment.
Regulates the
movement of
substances enteringand leaving the cell.
Allows the exchange
of nutrients,
respiratory gases and
wastes products
between the cell and
its environment.
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Chlorophyll captures theenergy of sunlightand
converts light energy into
chemical energy duringphotosynthesis.
The green pigment of
chlorophyllgives plantstheir colour.
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Stores chemicals
such as organicacids, sugar, amino
acids, mineral salts,
oxygen, carbondioxideand so on.
Regulates water
balance in plantcells.
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Maintains the shape of plant cells.
Provides mechanical strength and supporttoplant cells.
Protectsplants cells from ruptur ing due to the
movement of excess water into the cells.
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Forms a network of
transportation within
the cell.
Rough endoplasmic reticulum
(has ribosomes attached to itssurface)
Transports protein which is
synthesized in ribosomes.
Smooth endoplasmic reticulum
(does not have ribosome attach toits surface)
Transports and
synthesized fat and
glyserol
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Site of proteins synthesis.
They are either bound to the
endoplasmic reticulum or lie free in
the cytoplasm.
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The sites of cellular
respiration. Principle site of
energy production.
Energy generated orreleased in the form
of ATP (adenosine
triphosphate).
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Functions as a processing, packaging
and transport centreof carbohydrates,
proteins and glycoproteins.
These materials will be membrane-bound
and secrete through vesicles.
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As a digestive
compartments.
In certain unicellularorganisms, lysosomes
fuse with food vacuoles
and dispense their
enzymes into thesevacuoles to digest the
contents of the vacuoles
Lysosomes
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Comparison of
an Animal Cell
& a Plant Cell
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Both has nucleus, cytoplasm,
mitochondrion, ribosome, cell
membrane, rough endoplasmic
reticulum, smooth endoplasmic
recticulum and Golgi apparatus
Similarities
Animal Cell Plant Cell
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Animal Cell Plant CellDifferences
Do not have fixed shape Shape Have a fixed shape
Do not have cell walls Cell walls Have cell walls
Do not have vacuoles. If
present, vacuoles are usuallysmall and numerous
Vacuoles Have a large centralvacuole
Do not have chloroplasts ChloroplastsAll green plants have
chloroplast which contain
chlorophyll
Have centrioles centrioles Do not have centrioles
Carbohydrate is stored in the
form of glycogen Food storage
Carbohydrate is stored in
the form of starch
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The Density ofOrganelles in
Spesific Cells
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The number of organelles in each cell varies
according to type of organism and nature of the
cell.
For example,
more active cellswill possess more
mitochondriathan less active cells.
Abundant chloroplastsare found in the
palisade mesophyllcells than other parts of
the leaves.
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Require energy to propel through the uterus
towards the Fallopian tubes, so that
fertilisation can take place.
Sperm cells
High density of ______
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Contract and relax to
enable movement and
flight
Muscle cells
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Require large amounts of energy
during active cell division to produce
new cells
Cells in meristems
High density of ______
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Mesophyll palisade cells
Absorb sunlight during photosynthesis
High density of ______
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