DNA – The Code of Life:
Nucleic Acids:
Have capacity to store info that controls cellular activity and development of
entire organism.
>> by controlling synthesis in proteins
Enzymes are proteins that control chemical processes inside cells.
>> control structure and functioning of all organisms
Two nucleic acids in cells:
1. Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)
1. Deoxyribonucleic acid - DNA:
>> Three researchers who discovered the structure of DNA and won Nobel
Prize for physiology/medicine in 1962:
Maurice Wilkins
Francis Crick
James Watson
>> Researcher that had a degree in chem, but did not win Noble Prize:
Rosaland Franklin because she died before receiving it.
>> Two genetic discoveries that Francis Crick was involved in:
1. Providing genetic proof that triplet code was used in reading genetic
material in DNA and transferring information from nucleus
cytoplasm via RNA – where proteins are made.
2. Shown that DNA function: double-stranded molecule could birth
produce exact copies of itself (replicate) and carry genetic instructions.
Where is DNA found? Chromosomal material made up of
DNA, RNA and histone proteins as
Mainly in nucleus
found in a non-dividing cell.
Forms part of chromosomes that make up chromatin network.
What is extranuclear DNA?
Small amounts of DNA found outside nucleus in mitochondria in plants and animals
and chloroplasts in plants.
How is DNA made up?
Long twisted ladder.
2 strands twist to form a suitable, 3D double helix.
&
, What units make up DNA?
Nucleotides are small units that make up a long chain in a DNA molecule.
Each nucleotide is made up of a:
>> sugar molecule – deoxyribose (S) sugar found in DNA
>> phosphate molecule (P) backbone – sugar phosphate
>> nitrogenous base which may be:
- Adenine 4 diff bases =
- Thymine Complimentary 4 diff
- Guanine base pairs nucleotides
- Cytosine
Foundation of genetic code, instructing cells on how to synthesis enzymes
and other proteins.
How is double helix made up?
Outer two stands of ladder formed by chain alternating sugar / phosphate
links. Bonds between sugar and phosphate molecule are strong.
Rungs of ladder are formed from pairs of bases linked by weak hydrogen-
bonds.
Base pairs attached to sugar molecules.
How do these 4 bases link up?
Adenine bons with thymine/uracil (2 H-bonds)
Cytosine bonds with guanine (3 H-bonds)
How are base pairs classified?
Two groups of nitrogenous bases:
1) Purines:
>> two fused rings of nitrogen, carbon, and Hydrogen atoms.
2) Pyrimidines:
>> one ring of similar atoms and are much smaller than purines
>> e.g. thymine, cytosine, and uracil.
Bases are the same in all animals, whether a human, frog, cat etc.
How do organisms differ?
Their sequences in which nucleotides are strung together differ.
>> e.g. ACC TGA ≠ AGT CCA
Sequence in certain sections of DNA in human is different from same sections
in every other human being (except identical twins!)
&
Nucleic Acids:
Have capacity to store info that controls cellular activity and development of
entire organism.
>> by controlling synthesis in proteins
Enzymes are proteins that control chemical processes inside cells.
>> control structure and functioning of all organisms
Two nucleic acids in cells:
1. Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)
1. Deoxyribonucleic acid - DNA:
>> Three researchers who discovered the structure of DNA and won Nobel
Prize for physiology/medicine in 1962:
Maurice Wilkins
Francis Crick
James Watson
>> Researcher that had a degree in chem, but did not win Noble Prize:
Rosaland Franklin because she died before receiving it.
>> Two genetic discoveries that Francis Crick was involved in:
1. Providing genetic proof that triplet code was used in reading genetic
material in DNA and transferring information from nucleus
cytoplasm via RNA – where proteins are made.
2. Shown that DNA function: double-stranded molecule could birth
produce exact copies of itself (replicate) and carry genetic instructions.
Where is DNA found? Chromosomal material made up of
DNA, RNA and histone proteins as
Mainly in nucleus
found in a non-dividing cell.
Forms part of chromosomes that make up chromatin network.
What is extranuclear DNA?
Small amounts of DNA found outside nucleus in mitochondria in plants and animals
and chloroplasts in plants.
How is DNA made up?
Long twisted ladder.
2 strands twist to form a suitable, 3D double helix.
&
, What units make up DNA?
Nucleotides are small units that make up a long chain in a DNA molecule.
Each nucleotide is made up of a:
>> sugar molecule – deoxyribose (S) sugar found in DNA
>> phosphate molecule (P) backbone – sugar phosphate
>> nitrogenous base which may be:
- Adenine 4 diff bases =
- Thymine Complimentary 4 diff
- Guanine base pairs nucleotides
- Cytosine
Foundation of genetic code, instructing cells on how to synthesis enzymes
and other proteins.
How is double helix made up?
Outer two stands of ladder formed by chain alternating sugar / phosphate
links. Bonds between sugar and phosphate molecule are strong.
Rungs of ladder are formed from pairs of bases linked by weak hydrogen-
bonds.
Base pairs attached to sugar molecules.
How do these 4 bases link up?
Adenine bons with thymine/uracil (2 H-bonds)
Cytosine bonds with guanine (3 H-bonds)
How are base pairs classified?
Two groups of nitrogenous bases:
1) Purines:
>> two fused rings of nitrogen, carbon, and Hydrogen atoms.
2) Pyrimidines:
>> one ring of similar atoms and are much smaller than purines
>> e.g. thymine, cytosine, and uracil.
Bases are the same in all animals, whether a human, frog, cat etc.
How do organisms differ?
Their sequences in which nucleotides are strung together differ.
>> e.g. ACC TGA ≠ AGT CCA
Sequence in certain sections of DNA in human is different from same sections
in every other human being (except identical twins!)
&
