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This presentation provides an overview of protein synthesis, including the two main processes involved - transcription and translation. Key concepts such as RNA polymerase, double helix, sense and anti-sense strands, codons, anticodons, and ribosomes are covered in detail.
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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.
Transcription-RNA polymerase binds to double helix at promoter region RNA POLYMERASE DNA DOUBLE HELIX
Sense strand Anti-sense strand Bonds between bases are broken and DNA double helix unwinds
Free nucleotides from inside nucleus bind onto exposed DNA bases forming a molecule of mRNA Sense strand Free Nucleotides Anti-sense strand
mRNA When mRNA has formed, it moves away and the DNA reforms + DNA double helix rewinds
Poly-A Guanine “CAP” • 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. 5` end 3` end mRNA
Translation- Diagram of an anti-codon Anti Codon bases tRNA Amino acid
5` end 3` end Ribosome 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. 2 Codons mRNA
5` end 3` end Ribosome Peptide bond A second anti-codon comes along and after it has coded its amino acid, a peptide bond is formed between the 2 amino acids mRNA Anti Codon.
2nd and 3rd codons 5` end 3` end Peptide bond The first anti-codon detaches leaving its amino acid behind. The mRNA moves along ribosome and a third tRNA binds onto the third codon.