DNA structure & Function, Chromosome Function Flashcards
What did Freidrich Miescher do?
discovered nucleic acid in 1869
found cells all contained C,H, N2 and Ph
only found in nucleus of all cells
What did Avery, McLeod and McCarthy do?
studied transformation of R-type bacteria to S-type bacteria
centrifuged cells & incubated with bacteria
Treated with enzymes to break won different macromolecules- shows Dan must be the only transforming principle
what did Hershey & Chase do?
published a paper to prove DNA was generic material
studied bacteriophage
what must genetic material be?
stable over time
able to be faithfully replicated
able to control expression of traits
change in a controlled way
what structure is DNA?
double helix
what did Rosalind Franklin do?
discovered DNA is a double helix
crystallise proteins & X ray them
discovered had two coaxial molecules
what did Watson and crick do?
took franklins crystallography & proposed a structure
what is the structure of the DNA
double helix
linear polymer made of repeating units
- nucleotides
has directionality
antiparallel
what is a nucleotide?
sugar + base + phosphate
what is a nucleoside?
sugar + base
what end of C has 3’
with the hydroxyl group on it
what end of C has 5’
with the phosphate on it
complementary base pairs
large base always with small base
large base = purine
small base = pyrimidine
A-T has 2H bonds
C-G has 3 H bonds
what makes them complementary?
not symmetrical
major groove
minor groove
can see grooves in the way the helix twists
key role of heredity
genetic information carried in sequence of bases
quaternary code
easily stored and analysed, and passed on
