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TYPES OF NON CODING SEQUENCES

  GENES  The gene is a nucleic acid sequence that is necessary for function of gene product.  Gene may be a protein coding gene whose transcribed RNA is translated into proteins or RNA only genes.  Protein coding genes may be solitary or families or tandem repeats NON –CODING SEQUENCE   The non coding sequence are genes that do not encode the protein.  The amount of non-coding sequence in DNA of organism varies among species.  Eg-Human genome -98% non-coding genes  Prokaryotes -10% non-coding genes  Types of Non coding sequences The non coding sequences can be in the form of following Introns  Anti leader and Anti trailer sequence Promoter sequence Enhancers Pseudogenes Gene fragments Telomeres Non-coding functional RNA Cis-Trans regulatory elements INTRONS  Introns are non-coding sequence that transcribed into RNA  But precursor mRNA removed by splicing during processing.  The eukaryotic genome has large amount of introns...
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ORGANISATION OF GENOME

ORGANISATION OF GENOME  Chromatin is compact organisation of DNA sequences are structurally inaccessible and functionally inactive.  Within a cell the DNA is associated with proteins is called chromosomes.  The organisation found in both prokaryotic and eukaryotic cell.  The organisation of DNA is essential to fit a DNA of 2metre length (atypical human cell)into a nucleus that is only 10-15µm in diameter. ADVANTAGES OF ORGANISATION: Packaging of DNA into chromosomes hold several functions  First chromosome is a compact form of DNA that readily fits inside cell.  Second packaging DNA into chromosome serve to protect the DNA from damage. Naked DNA molecules are relatively unstable in cells. In contrast chromosomal DNA is extremely stable. Third only packed DNA can be transmitted efficiently to both daughter cells during cell division. Fourth chromosomes confers an overall organisation of DNA , that helps in gene expression and recombination. PROTEINS INVOLVED...
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DNA As Genetic material- Key experiments

DNA As Genetic material 1. GRIFFTH EXPERIMENT It is also called as as transformation principle . It involve in bacterial transformation.  Frederick giffth proposed this experiment. The pneumonia bacteria which causes pneumonia is used for this experiment Strains of bacteria:  1.Rough strain  It has rough appearance  It is avirulent and non pathogenic  It does not have capsule  2.Smooth strain  It has smooth glistering appearance  It has capsule made of polysaccharide  It is virulent pathogenic Strains  S types- SI, SII and SIII  R types-RI,RII and RIII  Both S and R types differ in each other antigen  Smooth forms may be mutated to rough forms but the changes are not reversible Procedure  Step 1  The laboratory mice inject With live RII pneumonia  The mice suffered no illness  Because RII pneumonia is avirulent  Step 2  But when mice inject with Virulent SIII pneumonia  The mice suffere...
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Centrifugation-notes

  CENTRIFUGATION-PRINCIPLE Sedimentation is basic principle of centrifugation. Sedimentation involves settling molecules due to gravitational force. Centrifugal force:   An object moves in circular motion at steady angular velocity where force direct object in outward direction is called centrifugal force. Centrifugation works on centrifugal force here axis of rotation is rotor and object is sample. BASIC PRINCIPLES OF SEDIMENTATION     RCF DERIVED Spherical biomolecule-example- protein If biomolecules are more viscous SEDIMENTATION COEFFICIENT (OR) SWEDBERG UNIT (OR)S20   Sedimentation coefficient is defined as sedimentation rate in per unit of centrifugal field .  S20=v/ω2 r  Sedimentation coefficient is defined in experimental value to the sedimentation constant at theoretical value in water at 20 degree celcius temperature. INSTRUMENTATION OF CENTRIFUGE:  The components of centrifuge were  1.CENTRIFUGE TUBES  2.ROTOR  3.MOTOR CO...
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