4. CELL WALL
1. a non living rigid structure .
2. Forms an outer covering for
plasama membrane.
function:
1) Determining Cell Shape.
2) Strength.
3) Controlling Turgor Pressure.
4) Passage of Substances.
5) Protection.
Primary wall:
• The wall which help to grow in
youger plant
• diminishes as cell get mature.
5. Endomembrane system
• the functionating of certain
membrane bound cytoplasmic
organelles is well coordinate.
• The organelles collectively form
endomembrane system.
• Consist of gogi complex ,
endoplasmic reticulum , plasma
membrane , lysosomes , plastids.
6. Endoplasmic reticulum
• Dicovered by porter
and thompson.
• It is a complex
membrane lined
network of flattened
sac, tubles etc..
• runs through out
cytoplasm of eukaryotic
cells.
• Cosist of 30-40% of
total endomembrane
system.
• Divides the
intercellular space into
7. • Has two main types:
Smooth endoplasmic reticulum
and
rough endoplasmic reticulum.
Functions:
1. Mechanical support
2. Conduction of information
3. Intercellular transport
4. Localisation of enzymes.
5. Large surface area.
Function of RER:
1. Protein for transport
2. Protein processing
Function of SER:
1. Storage.
8. Golgi apparatus
• Is a cytoplasmic organelle osf
smooth membrane sac.
• Dicovered by camillo golgi,
• Found in eukaryotic cells
(except mammalian
erythrocytes)
• Occur between nucleus and
exposed cell surface.
• Surrounded by zone of
cytoplasm which is devioded of
ribosomes, mitochondria, etc...
Functions:
Package materials. And important
for formation of glycoprotein.
9. Lysosomes and vacuole
lysosomes
• Membrane bound vesicular structure
• Formed by packaging of golgi
appartus.
• Very rich in hydrolytic enzymes.
• Enzymes are capable for digesting
carbohydrate, protein, lipid, mucleic
acid.
• Polpularly called as “suicide bags”,
Vacuoles:
• Membrane bound space found In
cytoplasm.
• Bounded by single membrane called
tonoplast,
• In amoeba, called contractile vacuole
and in proista food vacuole
10. •
mitochondria
These are double –membrane bound, sausage
–shaped semi-autonomous organelles.
• The electron micrograph shows that the
boundarymembranes are separated by a fluid
filled spacecalled outer compartment.
• The outer membrane is smooth but the inner
smooth projects in the form of many folds
calledcristae into the matrix.
• The matrix is rich in enzymes, a circular
DNA
• molecule and many small ribosomes.
• The inner membrane and the cristae bear a
number of particles, which have a spherical
head– piece (F1 subunit) and a stalk (F0
subunit) that is embedded in the lipid of the
membrane.
• The F0 – F1 combination functions as ATP
synthetase.
• The main function of mitochondria is aerobic
respiration and ATP synthesis
11. •
plastids
Plastids are double – membrane bound organelles
of different shapes, that are found only
• in plant cells and contain pigments and storage
products.
• These are three types of plastids, depending on
their colour and functions.
• Chromoplasts
• These are the coloured plastids containing mainly
the yellow, red and orange pigments (carotene and
xanthophylls).
• (iii) Chloroplasts
• These are the green plastids containing mainly
chlorophylls and very little of carotene and
xanthophylls.
• Chloroplasts may be lens – shaped, oval,spherical,
discoid, ribbon-like or cup –shaped
• Each chloroplast has a double membrane
• covering, enclosing the colourless matrix
• called stroma.
