DNA
• Hereditary material of cell to control activities of composition four nucleotides.1. d - adenosine monophosphate (d - AMP)
2. d - guanosine monophosphate (d - GMP)
3. d - cytidine monophosphate (d - CMP)
4. d - thymidine monophosphate (d - TMP)
nucleotides –> phosphodiester linkage –> polypeptide chain.
Nicotinamide adenine dinucleotide (NAD): Important enzymes in oxidation - reduction of cell. In 1951, Erwin Chargiff the ratio of different bases.A = T (equal ratio)
C = G (equal ratio)
Structure of DNA:
Maurice Wilkins and Roseland Franklin introduce X-ray differaction at same time.D.Watson and Francis Crick introduce sacle model of DNA.
DNA; Two polynucleotide chains or strands coiled in form of double helix.
DNA amount –> fixed
double in –> somatic cells
half in –> germ cells
First microbe genome sequenced 1995 Haemophilis Influenza.
RNA
• Ribonucleotides• Single stranded
• U instead of T
DNA –> RNA –> Protein
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Transcription Transloution
Types of RNA:
Synthesized by DNA in nucleus and moved out in cytoplasm.• mRNA
• rRNA
• tRNA
mRNA:
• 3 to 4 percent of total RNA.• Carries information from nucleus to ribosomes in cytoplasm where a.acid are arranged to make specific protein.
• Length depends on length of gene and protein for which it is Carrying message.
1000 a.acids –> 3000 Nucleotides
rRNA:
• 80 percent of total RNA.• Ribosomal protein; 40 - 50 percent pf it is present.
• Acts as a machinery/hardware for synthesis or combination of proteins.
• On ribosome surface –> mRNA and tRNA interacts to make protein.
tRNA:
• 10 - 20 percent of total RNA.• 75 to 90 nucleotides –> small molecules.
• Transfer a.acid –> ribosomes –> peptide chain.
• 1 tRNA for each a.acids.
• so 20 tRNA in total.
Nucleic acid and RNA:
• Discovered in 1869, F Miescher introduce nuclei pus of cell.
• Isolation from nuclei and acidic nature named as nucleic acid.
Types:
• Deoxyribonucleic acid –> in chromosomes –> in nuclei of cell.
• In mitochondria and chloroplast –> lesser extent.
• Ribonucleic acid –> in nucleolus in ribosomes in cytosol in smaller amounts in other parts of cell.
• Nucleic acid –> composition –> nucleotides.
• DNA –> Deoxyribonucleotides, RNA –> Ribonucleotides and Nucleotides.
Three subunits:
• 5’C monosaccharides (pentose sugar).
• Nitrogen containing base –> at pos 1.
• Phosphoric acid –> at positions.
1. Pentose sugar in DNA –> deoxyribose and Pentose sugar in RNA –> ribose
2. Nitrogeneous bases: • Single ringed pyrimidines –> C,T,U. • Double ringed purines –> A,G,C.
• Typical nucleotide –> Nitrogeneous bases attach to 1 pos of pentose sugar, while H³PO⁴ is attach to C at 5 position of pentose sugar.
• Base at 1 of pentose sugar.
• H³PO⁴ at 5 of pentose sugar.
Base + pentose sugar –> Nucleoside
Nucleoside + H³PO⁴ –> Nucleotide
ATP –> nucleotide –> energy currency of cell.
Conjugated Molecule:
• Two different molecule of different categories join to forn conjugated molecule.
Glycoprotein and Glycolipid –> integral part of plasma membrane.
• Cellular secretion –> Glycoprotein in nature.
(Nuleic acid + Protein) Nucleo Protein e.g: nucleohistones.
• Play role in gene expression.
The Cell
• Structural and function unit of life.
• Smallest unit carry –> all activities of life.
• Cell; building block of complex multicellular organisms.
Cell Theory:
Robert Hooke: In 1665 discovery and study of cell. Robert Hooke –> book is Micrographia. Robert Hooke prepared and studied thin section of cook under self made microscope in 19th century.Ideal: Cell an empty space.
Lorenz Oken: In 1805 German scientist –> all living beings made up of vesicles or cells.
Jean Baptist de-Lamarcle: In 1809 –> nobody can have a life if its constituent parts are not made up of cellular tissues.
Robert Brown: In 1831 –> discovery of nucleus proved the idea of Howke wrong.
German Schwann and Schleiden: Schwann zoologist in 1839 and Schleiden botanist in 1838 proposed cell theory. Cell has three parts. • Nucleus • Fluid around cytoplasm • Thin wall covering –> cell membrane cell wall is optional –> only in plants.
Rudolph Virchow: German physician –> new cells are formed only by division of previously existing cell. Virchow's words –> omnis cellula e cellula. Contrary to abiogenesis idea(living things arise from non-living.
Lious Pasteur: In 1862 –> experimental proof of virtual theory –> micro-organisms –> bacteria only formed by existing bacteria.
August Weissman: In 1880 –>all living cells have a common origin because of structural similarities.
Resolution of eye:
Human eye differentiate between two points that are 0.1mm apart.
1. Increased by lenses
2. Compound microscope –> 2.0μm resolution –> 500X that of naked eye.
Magnification of microscope:
Determined –> multiplying X value of ocular lens(10X) and X value of objective lens(40X).A micrope with these X values had 400X magnifying power.
Compound microscope:
• Resolution –> same –> 500X of naked eye.
• Source of illumination –> visible light.
Electron Microscope:
• illumination –> beam of electrons
• resolution –> 2-4 A° –> 500X greater than compound. Microscope and 2,50,000X than of naked eye.
Features of Cell Theory:
• All organisms beings made out or composed of one more cells.• All cell –> arise or emerge from pre-existing cells.
• Cell –>essential and primary or basic and structural unit of life.
Different cell specialized for Different functions:
Muscle cell –> contract and relax.
Nerve cell –> transmit impulse.
Gland cell –> secrete.
R.B.C –> Carry O².
Stomach cell –> secretes gastic juice.
Xylem cell –> transport water and mineral salt from roots to aerial parts of plants.
Phloem cells –> Translocates food.
sclerenchymatous cells –> give supports to plants.
Parenchymatous cells –> stores surplus food.
Chlorenchymatous cells –> carry photosynthesis.
Meristematic –> produce new cells for growth and development of plants.
Plant and animal cell have common plan of organization.
Structure of cell:
Studied under light and electron microscope.Cell Fractionation:
Tissues homogenized or disrupted by instrument and various parts separated by density gradient configuration.
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