Chapter 14 Flashcards
what was Griffith’s experiment?
in 1928 he was trying to figure out a vaccine for influenza
define Bacteriophages.
viruses that infect bacteria
what are differences of DNA and RNA?
DNA is composed of nucleotides
RNA is composed of proteins that contains 20 different amino acids (they are more chemically diverse)
what is a phosphodiester bond?
nucleotide monomers are joined together by a dehydration reaction involving 5’ phosphate of one nucleotide with the 3’ hydroxyl of another nucleotide
what is conservative DNA?
produces a new DNA and keeping an old DNA (2 orange and 2 blue)
what is a semiconservative DNA?
produces one new strand and one old (1 orange and one blue), they are spiraled together
what is dispersive DNA?
creates a new strand of old in new mixture
what bonds do DNA have?
Hydrogen bonds
what are chargaff’s rule one?
the proportion if A always equals that of T
the proportion of G always equals that of C
A=T and G=C
explain Chargaff’s second rule.
the ratio of G- C to A-T varies with different species
what where the scientists that discovered DNA double helix?
James Watson and Francis Crick
what did James Watson and Francis Crick use to discover the double helix?
Used Chargaff’s rule and Franklin’s diffusion studies
what did Rosalind Franklin discover?
Used X-ray diffraction to photograph DNA fibers to show the helical structure of DNA.
what does the nitrogenous base in DNA compose of?
A 5-carbon sugar, a phosphate group(PO4-)
purines- adenine and guanine
Pyrimidines- thymine and cytosine
what does the nitrogenous base in RNA compose of?
purines- adenine and guanine
pyrimidines- cytosine and urial
