Download DNA vs RNA

History of DNA
A Chargaff, Erwin
Discovered a relationship in the nitrogenous bases
ADENINE (A) = THYMINE (T)
GUANINE (G) = CYTOSINE (C)
B Rosalind Franklin (1952)
Took an X-ray of the DNA structure so the patterns could
be seen.
THE X-RAYS SHOW THAT DNA IS TWISTED AROUND EACH
OTHER LIKE A HELIX AND HAS 2 STRANDS.
X-ray of DNA
C Watson and Crick (1953)
Studied the structure of the DNA by building a 3-D model
of the molecule AFTER using clues from Franklin’s X-ray of
DNA.
They proposed that DNA is made up of 2 chains of
nucleotides held together by nitrogenous bases & that
the 2 strands are twisted together in a shape called a
double helix
Features
Name
DNA
Deoxyribonucleic Acid (DNA)
RNA
Ribonucleic Acid (RNA)
1. Phosphate Group – PO4
2. Sugar – Deoxyribose
3. Nitrogen Base – also called nitrogenous
bases
Chargaff’s Rule
* Adenine A
(Base pair rule)
* Guanine G
* Thymine T
A=T&C=G
* Cytosine C
NUCLEOTIDE
NUCLEOTIDE
Structure
1. Phosphate Group – PO4
2. Sugar - Ribose
3. Nitrogen Base
* Adenine A
* Guanine G
* Uracil U
* Cytosine C
Shape
(Description)
Location
Looks like a twisted ladder. Actually called a double
helix.
½ a ladder – a single stranded
Euk cells – DNA is ONLY in the nuclues
Prok cells – DNA is a single, circular chr in cytoplasm
Found in the nucleus (transcription) and in the
cytoplasm (translation)
Function
Store and transmit genetic information (heredity);
blueprints for life;
Instructions (CODE) for protein synthesis
Helper molecule
mRNA – copies & carries code out to ribosomes
rRNA – protein factories (ribosomes)
tRNA – transports amino acids; helps to construct
proteins