PROTEIN SYNTHESIS PRESENTATION Adenine Uracil Guanine Cytosine.
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Transcript of PROTEIN SYNTHESIS PRESENTATION Adenine Uracil Guanine Cytosine.
PROTEIN SYNTHESIS
PRESENTATION
Adenine
Uracil
Guanine
Cytosine
There are two processes involved:
• Transcription-Copying of DNA code to form mRNA.
• Translation-Conversion of RNA code into a sequence of amino acids.
RNA POLYMERASE
DNA DOUBLE HELIX
Transcription-RNA polymerase binds to double helix at promoter region
Sense strand
Anti-sense strand
Bonds between bases are broken and DNA double helix unwinds
Sense strand
Anti-sense strand
Free nucleotides from inside nucleus bind onto exposed DNA bases forming a molecule of mRNA
Free Nucleotides
+ DNA double helix rewinds
mRNA
When mRNA has formed, it moves away and the DNA reforms
mRNA
5` end3` end
Guanine“CAP”
Poly-A
•The 5` end of the polynucleotide mRNA is modified by a guanine cap which is thought to be a translation promoter.
•About 100 adenines (POLY A) are added to the 3` end which is thought to:
>to be a signal for the exit of mRNA from the nucleus.
>Protect mRNA from enzyme action.
Anti Codon bases
tRNA
Amino acid
Translation- Diagram of an anti-codon
2 Codons
mRNA
Ribosome
5` end3` end
Anti Codon.
2 codons enter the information processing region of ribosome.An anti-codon attaches to the bottom of ribosome and codes the amino acid with corresponding bases.
mRNA
Ribosome
5` end3` end
Anti Codon.
A second anti-codon comes along and after it has coded its amino acid, a peptide bond is formed between the 2 amino acids
Peptide bond
5` end
3` end
Peptide bond
2nd and 3rd codons
The first anti-codon detaches leaving its amino acid behind.
The mRNA moves along ribosome and a third tRNA binds onto the third codon.
The EndBy Sahira, Kulsoom and Sarah.