CELL WALL1. 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.
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.
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
• Has two main types:Smooth endoplasmic reticulum and rough endoplasmic reticulum.Functions:1. Mechanical support2. Conduction of information3. Intercellular transport4. Localisation of enzymes.5. Large surface area.Function of RER:1. Protein for transport2. Protein processingFunction of SER:1. Storage.
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.
Lysosomes and vacuolelysosomes• 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
• 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
• 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.