Summary DNA, RNA IB biology HL

1/ 2 6
. .
Structure of DNA and RNA 1/




Phosphate +
sugar +
organic base = nucleotide + 2 water


The sugar and phosphate form the "backbone" of the
nucleic acid with ,
the organic bases sticking .
out


DNA double helix (strands
is a are antiparallel
10 nucleotides
~
complete one turn of the helix :


Theory of knowledge
Rosaline Franklin 1950 - -
created X-ray 5
z
diffraction images that revealed the
bond
hydrogen
, 1



TX
↓ &
I



arrangement of atoms in molecules M - covalent
bond -
1
↓ & = -




Maurice Wilkins shared the know -

-v
ledge with James Watson ↓ & -, - 1




3 51
Watson Crick and Wilkins were
DNA
,

awarded Nobel Prize in 1962
.
Franklin died from oravian cancer
at age 37.

, The elucidation of the structure of DNA

·
Phoebus Levene from Russia-defined the components of nucleotide
,

-
nucleic acid-polymer; nucleotide-monomer

· Oswald Avery from Canada/USA
,
demonstrated that DNA
carries genetic information
· Erwin Chargaff from ,
Austria -

present in the same
A
amount T
as .
This led to idea of complementary base
pairs
· Linus Pauling-suggested a helix shape for some
proteins,
using X-ray crystallography
·
Rosaline Franklin Wilkins
, ,
Watson and Crick-shape of DNA
antiparallel strands to satisfy bond angles