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DNA Structure. Nucleotide = sugar + phosphate + nitrogen base. DNA wrapped around histones. Protein Synthesis: Transcription & Translation. Transcription : Making a copy of the blueprint. Morse Code Key. Using the Genetic Code: DNA :: mRNA :: Protein.
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DNA Structure
Protein Synthesis: Transcription & Translation
Transcription: Making a copy of the blueprint
Using the Genetic Code: DNA :: mRNA :: Protein • Get from ‘language’ of DNA (A,G,C,orT) to ‘language’ of protein (aa’s) • DNA’s ‘language’ is a triplet code in which 3 nucleotide bases (a codon) specify 1 amino acid in protein.
Steps in Transcription
Transcription: Note the free nucleotides
mRNA- final product of Transcription mRNA moves off to ribosome
Translation Building the protein from the plan
Using the Genetic Code: DNA :: mRNA :: Protein • Get from ‘language’ of DNA (A,G,C,orT) to ‘language’ of protein (aa’s) • DNA’s ‘language’ is a triplet code in which 3 nucleotide bases (a codon) specify 1 amino acid in protein.
Structure of a tRNA
Translation: purple = mRNA blue = ribosome yellow = tRNA (note anticodon) white = amino acids red = peptide bond
A Polysome: With more than one ribosome translating an mRNA at one time, it is possible to produce many polypeptides simultaneously from a single mRNA.
Protein Synthesis
In a prokaryotic cell, transcription and translation are coupled; that is, translation begins while the mRNA is still being synthesized. In a eukaryotic cell, transcription occurs in the nucleus, and translation occurs in the cytoplasm.