THEIR ROLE IN PROTEIN SYNTHESIS. Polymer of nucleotides Deoxyribose (5 carbon sugar) Phosphate...
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Transcript of THEIR ROLE IN PROTEIN SYNTHESIS. Polymer of nucleotides Deoxyribose (5 carbon sugar) Phosphate...
DNA – BASIC STRUCTURE
Polymer of nucleotides Deoxyribose
(5 carbon sugar) Phosphate group Nitrogen base
Adenine Guanine Thymine Cytosine
Hydrogen bonds Double helix - two
strands twisted
DNA – BASIC STRUCTURE
Sides – alternating sugar & phosphate grps
5’ end phosphate
3’ end sugar
Steps – base pairs Adenine – Thymine Cytosine – Guanine Connected by H-bonds
DNASTRUCTURE & FUNCTION
Blue prints for life Carries an
organisms genetic code
Carries instructions for making proteins: Immunology Metabolism Respiration Energy/Storage
Found in nucleus of cell
DNA - REPLICATION
Make a copy of DNA Occur prior to cell
division Steps:
Enzyme DNA polymerase unzips DNA
Two new “complimentary” strands built
RNA – BASIC STRUCTURE
Single strand Sugar – ribose Phosphate grp
Uracil replaces Thymine
3 Types Messenger (mRNA) Ribosomal (rRNA) Transfer (tRNA)
TRANSCRIPTION
Process used to make mRNA from DNA
Occurs in nucleus RNA polymerase
Enzyme splits DNA so RNA can form
Role of mRNA Carries directions
making protein to the ribosome
TRANSCRIPTION
Promoter Section DNA where
enzyme attaches TATA Box
Repeating sequence bases – signals where transcription should begin
Immediately followed by start codon AUG
TRANSCRIPTION
CODONS – Groups 3 bases code
for an amino acid AUG – “start” codon,
codes for methianine 64 different “3-letter”
codes for 20 different amino acids
Terminator – stop signals UGA, UAA, UAG
TRANSLATION Assembly of amino acids at the ribosome to
produce a protein Initiation – joining of mRNA, tRNA & ribosome
TRANSLATION
Elongation – the joining of amino acids tRNA bring A. acids
to ribosomes Anticodons on
tRNA match to codons on mRNA
Termination – production A. acid stops – no tRNA to match STOP codon
POINT MUTATIONS Single base is changed – change in 1 a.
acid Silent (no change A.Acid) or result in
disease