DNA - The Code of Life
Nucleic acids:
Have the capacity to store the information that controls cellular activity and the development of
an entire organism, by controlling protein synthesis.
Enzymes – control Main structural
chemical processes component
2 types:
- RNA
- DNA
DNA – deoxyribose nucleic acid
History
The structure: (1950’s)
- Maurice Wilkins (looked at X-ray crystallography)
- Rosaline Franklin (looked at X-ray crystallography)
- Francis Crick (analysed the data collected by above 2 and built a model)
- James Watson (analysed the data collected by above 2 and built a model)
1953
Watson and Crick
Due to A=T and C=G pairings, when the strands separate, they serve as a template for a
complementary new chain.
1961
Crick and Sydney Brenner
Triplet code was used in reading genetic material in DNA and transferring this information.
Both discoveries proved:
- could produce exact copies of itself
- could carry genetic instructions
Nobel prize
For physiology/medicine:
- Watson
- Crick
- Wilkins
Franklin did not receive this award as she died before it was awarded.
, Location of DNA
= Mainly in the nucleus, where it forms an important part of the chromosomes that make up the
chromatin network. (But there is extracellular DNA in mitochondria and chloroplasts)
Chromosomal material made up of DNA, RNA and histone proteins as found in a non-dividing
cell.
Chromatin network:
- When at rest = strands in a mess (non-visible)
- When working = condenses (visible)
Wraps up around histones
Structure of DNA
= Polymer
Long chain of similar elements joined end to end.
Monomers
Made of a building block
called nucleotides
Shape: Double helix
2n somatic cell n germline cell
(Diploid) (Haploid)
(Gametes)
= 46 # = 23 # - sperm cell
(23 pairs) Homologous pairs
- egg cell
Pair 23: Gonosomes (sex #)
xx = female
xy = male
Pair 1-22: Autosomes
Nucleic acids:
Have the capacity to store the information that controls cellular activity and the development of
an entire organism, by controlling protein synthesis.
Enzymes – control Main structural
chemical processes component
2 types:
- RNA
- DNA
DNA – deoxyribose nucleic acid
History
The structure: (1950’s)
- Maurice Wilkins (looked at X-ray crystallography)
- Rosaline Franklin (looked at X-ray crystallography)
- Francis Crick (analysed the data collected by above 2 and built a model)
- James Watson (analysed the data collected by above 2 and built a model)
1953
Watson and Crick
Due to A=T and C=G pairings, when the strands separate, they serve as a template for a
complementary new chain.
1961
Crick and Sydney Brenner
Triplet code was used in reading genetic material in DNA and transferring this information.
Both discoveries proved:
- could produce exact copies of itself
- could carry genetic instructions
Nobel prize
For physiology/medicine:
- Watson
- Crick
- Wilkins
Franklin did not receive this award as she died before it was awarded.
, Location of DNA
= Mainly in the nucleus, where it forms an important part of the chromosomes that make up the
chromatin network. (But there is extracellular DNA in mitochondria and chloroplasts)
Chromosomal material made up of DNA, RNA and histone proteins as found in a non-dividing
cell.
Chromatin network:
- When at rest = strands in a mess (non-visible)
- When working = condenses (visible)
Wraps up around histones
Structure of DNA
= Polymer
Long chain of similar elements joined end to end.
Monomers
Made of a building block
called nucleotides
Shape: Double helix
2n somatic cell n germline cell
(Diploid) (Haploid)
(Gametes)
= 46 # = 23 # - sperm cell
(23 pairs) Homologous pairs
- egg cell
Pair 23: Gonosomes (sex #)
xx = female
xy = male
Pair 1-22: Autosomes
