BIO RNA DNA

quiz

watson and crick:

• double helix, 2 strands

• stole work from rosalind franklin

• awarded nobel prize in medicine in 1962

base pairing

hydrogen bonds form between certain bases a = t ( 2 hydrogen bonds ) g = c ( 3 hydrogen bonds )

rosalind franklin’s photograph 51:

• x-ray diffraction

erwin chargaff:

• observed ( c ) = ( g ) & ( a ) = ( t )

• chargaff’s rules → a pairs with t & c pairs with g

nitrogenous bases:

• 4 nucleotides made up of 4 nitrogenous bases

• purines ( 2 rings )

  • adenine ( a )

  • guanine ( g )

• pyrimidines ( 1 ring )

  • cytosine ( c )

  • thymine ( t )

    
    

• p ( phosphate ) always stays the same, sugar always stays the same, nitrogenous base does not stay the same ( a, c, g, t )

dna

• dna is a macromolecule, polymer

• made up or repeated

  • subunits = monomer = nucleotide

• nucleotide has 3 parts

dna

• monomer is to polymer : nucleotide is to dna : amino acid is to protein

• single unit : bigger unit that is made up of the polymerized single units

dna

• macromolecule is the big thing

• polymer is the repeated thing that makes up the molecule

• monomer is a single unit of these repeated things

dna

• amino acids polymerize to make a protein

• monomer - nucleotides

• 5-carbon sugar ( deoxyribose )

• phosphate

• nitrogenous base

hershey and chase used bacteriophage:

• virus that infects & kills a bacteria

• made of dna ( containing phosphorus ) and protein coat ( containing sulfur )

• tracked these elements using radioactive isotopes

• hershey-chase used a bacteriophage virus to confirm that dna was the transforming factor 

hershey-chase:

• many thought dna was too simple to contain the information of life

• debate → protein or dna

• hershey and chase wanted to confirm whether dna was the transforming factor

oswald avery:

• broke apart s-strain cells

• deductive reasoning

• isolated each component of the cell

  • lipid ≠ still s

  • protein ≠ still s

  • carbohydrate ≠ still s

  • dna

  • rna ≠ still s

• discovered dna was the transforming factor

griffith:

• bacterial transformation

  • 1 bacteria was changed into another strain

  • transforming factor contains genetic information

  • but what is the transforming factor?

• living s-strain pneumococcus → lethal

• living r-strain pneumococcus → non-toxic

• heat killed s-strain pneumococcus → non-toxic

• heat killed s-strain pneumococcus + live r-strain pneumococcus → lethal

  • s-strain pneumococcus inherited