Tab 1
, DNA:the code of life
DNA and RNA are macromolecules called nucleic acids.The building blocks of nucleic acids
are called nucleotides.
Location of DNA
In the nucleus (nuclear DNA)
In the mitochondria (mitochondrial DNA)
DNA consists of two strands that form a double helix structure.
Nucleotides are monomer that make up DNA molecule,Each nucleotides consists of a
deoxyribose sugar molecule,phosphate group and nitrogenous base.
.Adenine always pairs with Thymine
.Guanine always pairs with Cytosine
Adenine and Guanine are double ring structures called purines.
Cytosine and Thymine are single ring structures called pyrimidines.
One purine pairs with one pyrimidine;ensuring that the width of the DNA molecule remains the
same.
HISTORY OF THE DISCOVERY OF DNA MOLECULE
.Edwin Chargaff:concluded that DNA was made up of four different bases
viz.adenine,thymine,cytosine and guanine.
.Maurice Wilkins and Rosalind Franklin:studied the structure of DNA using X-rays.
.James Watson and Francis Crick:developed the double stranded, helical structure of DNA.They
received the Nobel Prize(1962) for the discovery of the structure of DNA, and Wilkins received
an award for his X-ray photograph.
DNA Replication
.this process occurs during interphase before mitosis begins
.during this process a DNA molecule makes an exact copy(replica) of itself
What happens during the process:
The double helix of DNA unwinds to appear as a ladder.Weak hydrogen bonds between
nitrogenous bases break due to enzyme action,and the two DNA strands separate. Both DNA
strands serve as templates. Free nucleotides from the nucleoplasm arrange themselves
complementary to the bases of original DNA strands.Two identical DNA molecules are
formed.Each molecule consists of one original and one new DNA strand
.
, DNA:the code of life
DNA and RNA are macromolecules called nucleic acids.The building blocks of nucleic acids
are called nucleotides.
Location of DNA
In the nucleus (nuclear DNA)
In the mitochondria (mitochondrial DNA)
DNA consists of two strands that form a double helix structure.
Nucleotides are monomer that make up DNA molecule,Each nucleotides consists of a
deoxyribose sugar molecule,phosphate group and nitrogenous base.
.Adenine always pairs with Thymine
.Guanine always pairs with Cytosine
Adenine and Guanine are double ring structures called purines.
Cytosine and Thymine are single ring structures called pyrimidines.
One purine pairs with one pyrimidine;ensuring that the width of the DNA molecule remains the
same.
HISTORY OF THE DISCOVERY OF DNA MOLECULE
.Edwin Chargaff:concluded that DNA was made up of four different bases
viz.adenine,thymine,cytosine and guanine.
.Maurice Wilkins and Rosalind Franklin:studied the structure of DNA using X-rays.
.James Watson and Francis Crick:developed the double stranded, helical structure of DNA.They
received the Nobel Prize(1962) for the discovery of the structure of DNA, and Wilkins received
an award for his X-ray photograph.
DNA Replication
.this process occurs during interphase before mitosis begins
.during this process a DNA molecule makes an exact copy(replica) of itself
What happens during the process:
The double helix of DNA unwinds to appear as a ladder.Weak hydrogen bonds between
nitrogenous bases break due to enzyme action,and the two DNA strands separate. Both DNA
strands serve as templates. Free nucleotides from the nucleoplasm arrange themselves
complementary to the bases of original DNA strands.Two identical DNA molecules are
formed.Each molecule consists of one original and one new DNA strand
.
