2.1 Cell Structure and Cell ion

8/14/2019 2.1 Cell Structure and Cell ion

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2.0 CELL STRUCTUREAND ORGANISATION


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2.1 Cell Structure and Function

Cell the basic unit of living thing

Living component of a cell is called the

protoplasmProtoplasm consist of the cytoplasm and the

nucleus and surrounded by a plasma

membrane

The cytoplasm contains organelles


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The organelles consist of

a) nucleusb) mitochondria

c) chloroplasts

d) vacuoles

e) ribosomes

f) lysosomes

g) golgi apparatus

h) endoplasmic reticulum

i) centrioles


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Exercise

1. Draw a plant and an animal cell.


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a) Cell membrane

- general terms that refers to any membrane

found within a cell

- the cell surface membrane which encloses the

content of the cell is called the plasmamembrane

- made of proteins and lipids

- form a boundary which separates the content of

a cell from outer environment- semi-permeable and act as a selective barrier

- regulates the movement of substances into and

out of the cytoplasm

The Cellular Components Of Animal And

Plant Cell And Their Functions


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b) Cell wall

- only can be found in plant cell

- a rigid outer layer that surrounds theplasma membrane

- composed of cellulose, a tough and fibrous

carbohydrate

- permeable to all fluids

- provide mechanical support

- give shape

- protect plant cell from rupturing


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c) Nucleus

- largest organelle in the cell

- consist of 3 main componenti) Nuclear envelope separates the

nucleus content from the cytoplasm

ii) Chromatin carries the genetic

material (DNA deoxyribonucleic acid)

iii) Nucleolus darker and dense region

- carry genetic information which

determines the characteristics andfunction of a cell

- controls all the activities which take place in

the cell


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d) Vacuole

- a fluid-filled sac, surrounded by

tonoplast (semi-permeable membrane)- the fluid inside the vacuole is called cell

sap

- act as a storage place in a cell

- contains water, organic acids, sugars,

amino acids, mineral salts, waste substance,

pigments and metabolic by-product

- in freshwater organism (Paramecium sp.)have contractile vacuole to regulate

water balance

- support herbaceous plants from wilting easily


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e) Mitochondria

- singular-mitochondrion- the site of cellular respiration which

release energy when food substances

(glucose) are broken down by enzymes in themitocondria

- energy is released in the form of ATP

(adenosine triphosphate) which can bereadily used by cells


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f) Endoplasmic Reticulum (ER)

- consist of a network of folded membranes

forming interconnected tubules/sac in the

cytoplasm

- the membranes are continuous with the

nuclear membrane


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- 2 forms

(i) Rough ER

the outer surface cover with

ribosomes

- transports proteins (enclosed in

vesicles) made by the ribosomes

can be transported from one part

of the cell to another


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(ii) Smooth ER

smooth outer surface, lack of

ribosomes

- the site of important metabolic

reactions (synthesis of lipids and

detoxification of drugs and poison)


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g) Ribosomes

- compact, spherical organelles found

attached on the surface of rough ER

or suspended freely in the cytoplasm

- consist of two sub-unit, one small and one

large, each comprises a type of

ribonucleic acid (RNA) and protein

- site of protein synthesis

- use information carried by the

chromosome to make protein


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h) Golgi apparatus

- consist of a stack of flattenedmembranous sacs

- new membrane is continuously added to

one end and buds of as vesicles at theother end

- function as a processing, packaging and

transporting centre of carbohydrates,proteins, phospholipids and glycoprotein


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i) Lysosomes

- membrane bound sac that contain

hydrochloric acid that digest and break

down complex organic molecule (protein,

lipids, polysaccharides and nucleic acid)

- eliminate damage or worn outorganelles

and help the cell renew itself

- can fuse with food vacuoles, digest thecontent and the breakdown product pass

into cytoplasm and become the cell

nutrient


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j) Centrioles

- small cylindrical structure that occur in

pairs located just outside the nucleus

- composed of complex arrangement ofmicrotubules

- not present in plant cell

- form spindle microtubules during celldivision


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k) Chloroplast- typically lens-shaped

- membranous structure contain green

pigment chlorophyll- chlorophyll captures the energy of

sunlight and converts light energy into

chemical energy during photosynthesis


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Exercise

1. Complete this table:

4. Lysosomes

3. Golgi apparatus

2. Mitochondria

1. Nucleus

FunctionsCellular components

A


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as a digestive compartments4. Lysosomes

a processing, packaging andtransport centre of

carbohydrates, proteins and

glycoproteins

3. Golgi apparatus

the site of cellular respiration

which releases energy in the

form of ATP

2. Mitochondria

Controls the activities of acell

contains DNA which

determine the characteristics

of a cell and its metabolic

reaction

1. Nucleus

FunctionCellular components

Answer


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Do not haveHaveCentrioles

Carbohydrate is stored

in the form of starch.

Carbohydrate is stored

in the form of

glycogen.

Food storage

Have a large central

vacuole.

Usually small and

numerous ,filled with

food or water.

Vacuoles

Have chloroplastDo not havechloroplasts.

Chloroplast

Have cell walls.Do not have cell walls.Cell wall

Have a fixed shape.Do not have a fixed

shape.

Shape

Plant cellsAnimal cellsStructure/

characteristic

Answer


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The similarities between animal and plant

cells

Both have a nucleus, cytoplasm, a plasma

membrane, Golgi apparatus, mitochondria,endoplasmic reticulum and ribosomes.


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The Density of Organelles in

Specific Cells

Different cells in the body perform different

functions

The density/abundance of certain organelles

found in a cell is related to the specific

function

The density of organelles in specific cells.doc
http://the%20density%20of%20organelles%20in%20specific%20cells.doc/http://the%20density%20of%20organelles%20in%20specific%20cells.doc/http://the%20density%20of%20organelles%20in%20specific%20cells.doc/

2.1 Cell Structure and Cell ion

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