DNA and RNA 20-01-2026
● Nucleotides= building blocks of both DNA and RNA.
● Nucleic Acid= Many nucleotides put together
● Watson and Crick discovered the shape of DNA
Nucleotide structure
Nitrogenous bases:
● T- thymine(only in DNA)
● A- Adenine
● C-Cytosine
● G-Guanine
● U-Urcil (only in RNA)
Pairs:
● Thymine joins to Adenine
● Cytosine joins to Guanine
● In RNA, Adenine joins with Uracil
DNA structure
● Structure: Double stranded, double helix
● Function:DNA makes up genes which carry hereditary information
● Location: Nucleus, Mitochondria and chloroplasts(only in plants)
RNA structure
● Function: RNA plays a role in protein synthesis.
● Structure:Single stranded. mRNA(messenger) and tRNA(transfer).
● Location:mRNA is formed in the Nucleus and functions at the Ribosome. tRNA is located
in the Cytoplasm.
DNA RNA
Double stranded Single stranded
Deoxyribosome sugar Ribose sugar
A,T,G,C A,U,G,C
Code of genes Protein synthesis
,DNA Replication 20-01-2026
● Takes place in the Interphase, in the Nucleus to create identical copies of DNA needed
for mitosis or meiosis(replace, repair or reproduce)
It happens when:
● Double helix unwinds
● DNA unzips/weak hydrogen bonds break/ into TWO SEPARATE strands
● BOTH strands act as a template.
● Hydrogen bonds reform
● DNA rewinds and rezips
● Form TWO IDENTICAL strands
ALWAYS mention the type of nucleotide (DNA or RNA).
Extra:
● Free floating DNA nucleotides from nucleoplasm
● join to their COMPLEMENTARY DNA base triplets OR A-T and G-C
● Adenine(A) joins to Thymine(T)
● Guanine(G) joins to Cytosine(C)
DNA Profiling 20-01-2026
Use of DNA profiling:
PATERNITY TEST
● determining the father of the child.
● links to how the child will inherit 50% of their DNA from each parent
● 50% of the markers match the mother and 50% of the rest of the markers match the
father
FORENSICS
● Determine who the criminal is.
● ALL the markers on the DNA profile must match.
● Identifying genetic disorders.
● Species diversity.
, Transcription 21-01-2026
● Takes place during protein synthesis in the Nucleus to transport code from DNA to
ribosome to create protein
How:
● Double helix unwinds
● DNA unzips/weak hydrogen bonds break into TWO SEPARATE strands
● mRNA now has the coded message for protein synthesis
● Moves from nucleus to cytoplasm attaches to ribosome
● Free floating RNA nucleotides from nucleoplasm
● join to their COMPLEMENTARY DNA base triplets OR A-U and G-C
● This produces mRNA
Translation 21-01-2026
When: Protein synthesis
Where: Ribosome in cytoplasm
Why: To translate the mRNA into a functional set of amino acids joined by peptide bonds
forming a protein.
How:
● mRNA attaches itself into the ribosome the ribosome reads 3 letters at a time called a
CODON
● this codon matches with the ANTICODON found on the tRNA
● The tRNA delivers the amino acids. These amino acids form a PEPTIDE BOND between
each other.
● To form the required PROTEIN.
● Each tRNA carries a specific amino acid
● the tRNA anticodon matches with the complementary mRNA codon
● The tRNA brings the REQUIRED amino acid to the ribosome
● Nucleotides= building blocks of both DNA and RNA.
● Nucleic Acid= Many nucleotides put together
● Watson and Crick discovered the shape of DNA
Nucleotide structure
Nitrogenous bases:
● T- thymine(only in DNA)
● A- Adenine
● C-Cytosine
● G-Guanine
● U-Urcil (only in RNA)
Pairs:
● Thymine joins to Adenine
● Cytosine joins to Guanine
● In RNA, Adenine joins with Uracil
DNA structure
● Structure: Double stranded, double helix
● Function:DNA makes up genes which carry hereditary information
● Location: Nucleus, Mitochondria and chloroplasts(only in plants)
RNA structure
● Function: RNA plays a role in protein synthesis.
● Structure:Single stranded. mRNA(messenger) and tRNA(transfer).
● Location:mRNA is formed in the Nucleus and functions at the Ribosome. tRNA is located
in the Cytoplasm.
DNA RNA
Double stranded Single stranded
Deoxyribosome sugar Ribose sugar
A,T,G,C A,U,G,C
Code of genes Protein synthesis
,DNA Replication 20-01-2026
● Takes place in the Interphase, in the Nucleus to create identical copies of DNA needed
for mitosis or meiosis(replace, repair or reproduce)
It happens when:
● Double helix unwinds
● DNA unzips/weak hydrogen bonds break/ into TWO SEPARATE strands
● BOTH strands act as a template.
● Hydrogen bonds reform
● DNA rewinds and rezips
● Form TWO IDENTICAL strands
ALWAYS mention the type of nucleotide (DNA or RNA).
Extra:
● Free floating DNA nucleotides from nucleoplasm
● join to their COMPLEMENTARY DNA base triplets OR A-T and G-C
● Adenine(A) joins to Thymine(T)
● Guanine(G) joins to Cytosine(C)
DNA Profiling 20-01-2026
Use of DNA profiling:
PATERNITY TEST
● determining the father of the child.
● links to how the child will inherit 50% of their DNA from each parent
● 50% of the markers match the mother and 50% of the rest of the markers match the
father
FORENSICS
● Determine who the criminal is.
● ALL the markers on the DNA profile must match.
● Identifying genetic disorders.
● Species diversity.
, Transcription 21-01-2026
● Takes place during protein synthesis in the Nucleus to transport code from DNA to
ribosome to create protein
How:
● Double helix unwinds
● DNA unzips/weak hydrogen bonds break into TWO SEPARATE strands
● mRNA now has the coded message for protein synthesis
● Moves from nucleus to cytoplasm attaches to ribosome
● Free floating RNA nucleotides from nucleoplasm
● join to their COMPLEMENTARY DNA base triplets OR A-U and G-C
● This produces mRNA
Translation 21-01-2026
When: Protein synthesis
Where: Ribosome in cytoplasm
Why: To translate the mRNA into a functional set of amino acids joined by peptide bonds
forming a protein.
How:
● mRNA attaches itself into the ribosome the ribosome reads 3 letters at a time called a
CODON
● this codon matches with the ANTICODON found on the tRNA
● The tRNA delivers the amino acids. These amino acids form a PEPTIDE BOND between
each other.
● To form the required PROTEIN.
● Each tRNA carries a specific amino acid
● the tRNA anticodon matches with the complementary mRNA codon
● The tRNA brings the REQUIRED amino acid to the ribosome
