Taneil Thompson
DNA- Code of Life
PLEASE NOTE THAT I HAVE SIFTED THROUGH THE IEB FINAL PAPERS
FROM 2011 TO 2018 AND ADDED SOME INFORMATION THAT KEPT
COMING UP. THIS INFORMATION IS IN PINK. I HAVE ALSO CHECKED
THROUGH THE SAGS DOCUMENT TO MAKE SURE THAT ALL THE
RELEVANT INFORMATION IS HERE. J
NUCLEIC ACIDS:
-‘molecules of life’
-control synthesis of proteins
-because proteins are enzymes, they control chemical
processes inside cells
-therefore, proteins control structure and functioning of
living organisms
1. Deoxyribonucleic Acid (DNA)
2. Ribonucleic Acid (RNA)
1. Deoxyribonucleic Acid (DNA):
-Discovered by Maurice Wilkins, Rosalind Franklin, Francis Crick and
James Watson.
-1962: Nobel Prize for physiology/ medicine awarded to Watson, Crick
and Wilkins (Franklin had died at age 37 from cancer)
Where: Extracellular DNA:
-nucleus of cell -DNA found outside nucleus in
-forms important part of mitochondria in plants and animals
chromosomes that make up OR chloroplasts in plants
chromatin (chromosomal -‘extranuclear DNA’
material made up of DNA,
RNA and histone proteins in
non-diving cell) network
-coiled to fit in nucleus, 2
metres in each human cell.
SAHETI School, 2019 1
, Taneil Thompson
-nucleotides made up of:
1. Sugar molecule- deoxyribose Make-up of DNA:
(S) -double helix:
2. Phosphate molecule (P) 1. Two outer strands formed by chain
3. Nitrogenous base: of altering sugar-phosphate links.
a) Adenine (A)
Bonds are strong between these.
b) Thymine (T)
c) Guanine (G)
2. Rungs formed of pairs of bases
d) Cytosine (C) (attached to sugar) linked by weak
hydrogen bonds
-polymer made up of monomers
called nucleotides
- (A) only bonds with (T) or Purines:
Uracil (U) with 2 hydrogen -Two fused rings of nitrogen,
bonds carbon and hydrogen atoms.
-(C) only bonds with (G) with 3 - [(G) and (A)]
hydrogen bonds Pyrimidines:
-sequences of these nucleotides -One ring of similar atoms,
determines genetic code of smaller than purines.
organism - [(T), (C) and (U)]
Role of DNA:
-carry hereditary information in each cell in the form of genes
-provide blueprint for organism’s growth and development (codes for
protein synthesis)
-replicates so that genetic information is passed on to daughter cells
during cell division, ensure carrying on genetic code between
generation
SAHETI School, 2019 2
DNA- Code of Life
PLEASE NOTE THAT I HAVE SIFTED THROUGH THE IEB FINAL PAPERS
FROM 2011 TO 2018 AND ADDED SOME INFORMATION THAT KEPT
COMING UP. THIS INFORMATION IS IN PINK. I HAVE ALSO CHECKED
THROUGH THE SAGS DOCUMENT TO MAKE SURE THAT ALL THE
RELEVANT INFORMATION IS HERE. J
NUCLEIC ACIDS:
-‘molecules of life’
-control synthesis of proteins
-because proteins are enzymes, they control chemical
processes inside cells
-therefore, proteins control structure and functioning of
living organisms
1. Deoxyribonucleic Acid (DNA)
2. Ribonucleic Acid (RNA)
1. Deoxyribonucleic Acid (DNA):
-Discovered by Maurice Wilkins, Rosalind Franklin, Francis Crick and
James Watson.
-1962: Nobel Prize for physiology/ medicine awarded to Watson, Crick
and Wilkins (Franklin had died at age 37 from cancer)
Where: Extracellular DNA:
-nucleus of cell -DNA found outside nucleus in
-forms important part of mitochondria in plants and animals
chromosomes that make up OR chloroplasts in plants
chromatin (chromosomal -‘extranuclear DNA’
material made up of DNA,
RNA and histone proteins in
non-diving cell) network
-coiled to fit in nucleus, 2
metres in each human cell.
SAHETI School, 2019 1
, Taneil Thompson
-nucleotides made up of:
1. Sugar molecule- deoxyribose Make-up of DNA:
(S) -double helix:
2. Phosphate molecule (P) 1. Two outer strands formed by chain
3. Nitrogenous base: of altering sugar-phosphate links.
a) Adenine (A)
Bonds are strong between these.
b) Thymine (T)
c) Guanine (G)
2. Rungs formed of pairs of bases
d) Cytosine (C) (attached to sugar) linked by weak
hydrogen bonds
-polymer made up of monomers
called nucleotides
- (A) only bonds with (T) or Purines:
Uracil (U) with 2 hydrogen -Two fused rings of nitrogen,
bonds carbon and hydrogen atoms.
-(C) only bonds with (G) with 3 - [(G) and (A)]
hydrogen bonds Pyrimidines:
-sequences of these nucleotides -One ring of similar atoms,
determines genetic code of smaller than purines.
organism - [(T), (C) and (U)]
Role of DNA:
-carry hereditary information in each cell in the form of genes
-provide blueprint for organism’s growth and development (codes for
protein synthesis)
-replicates so that genetic information is passed on to daughter cells
during cell division, ensure carrying on genetic code between
generation
SAHETI School, 2019 2
