Translation(Protein Synthesis
Translation (Protein Synthesis)
Translation· Processing of translating the language of RNA into the language of protein·Components: mRNA transcript (which we're translating - the message or genetic code): Ribosome (machinery that makes the protein - our writing instrument)·tRNA (aminoacid carrier-ourtranslator): Amino acids (what we connect together to make the protein - the words weusetoformourtranslation)
Translation • Processing of translating the language of RNA into the language of protein. • Components • mRNA transcript (which we’re translating – the message or genetic code) • Ribosome (machinery that makes the protein – our writing instrument) • tRNA (amino acid carrier – our translator) • Amino acids (what we connect together to make the protein – the words we use to form our translation)
Information translation· Ribosomes synthesize proteins by reading the nucleotide sequence of mRNAsand polymerizing amino acids in an N→C direction.? However, there is no obvious chemical affinity between the purine andpyrimidine bases and the 20 different amino acids.· Francis Crick reasoned that adapter molecules must bridge thisinformation gap. These adapter molecules must interact specifically withboth nucleic acids (mRNAs) and amino acids
Information translation • Ribosomes synthesize proteins by reading the nucleotide sequence of mRNAs and polymerizing amino acids in an N→C direction. • However, there is no obvious chemical affinity between the purine and pyrimidine bases and the 20 different amino acids. • Francis Crick reasoned that adapter molecules must bridge this information gap. These adapter molecules must interact specifically with both nucleic acids (mRNAs) and amino acids
The Genetic CodeTABLE22-1TheStandardGeneticCodeThrdFirstPositionPesitioeSecond Positiod(s'end)(3remd): A triplet codon specifies a single amino acidUUU PheUCUUAUTyYUGUCySUOUUCPheUCCSeUACUGCTyCUUAUCA: There are 20 amino acids but 64 codonsUGAStoPUAGSIOPUUUCCCGUSCULCAUHhUACUCCGCCCCPnCACHArg: The code is degenerate (3rd base wobble)CAACGACUACCGlnProArgCcuCCGGAUUT: Code practically identical in all life formsAUCAGCtecACOAUA-ACAAGAAUGGACOAACAGG: Three stop codonsGUUGGUGHUGUCVaGCCAlaGACANDGGCGhyA0GUAValGCAAlaGluGGAGhyGAAcG(don'tspecifyaminoacids)
The Genetic Code • A triplet codon specifies a single amino acid • There are 20 amino acids but 64 codons • The code is degenerate (3rd base wobble) • Code practically identical in all life forms • Three stop codons (don’t specify amino acids)
The Genetic Code Is a Triplet Code: A group of three bases codes for one amino acid.: The code is not overlapping: The base sequence is read from a fixed starting point without punctuation: The code is degenerate, meaning that, with the exception of Met and Trp, eachamino acid can be coded by any of several triplets? Codons representing the same amino acid tend to be similar in sequence.: The genetic code is unambiguous. Each of the 61 sense" codons encodes onlyone amino acid.· The genetic code is “universal." Codon assignments are virtually the samethroughout all organisms
The Genetic Code Is a Triplet Code • A group of three bases codes for one amino acid. • The code is not overlapping. • The base sequence is read from a fixed starting point without punctuation. • The code is degenerate, meaning that, with the exception of Met and Trp, each amino acid can be coded by any of several triplets. • Codons representing the same amino acid tend to be similar in sequence. • The genetic code is unambiguous. Each of the 61 “sense” codons encodes only one amino acid. • The genetic code is “universal.” Codon assignments are virtually the same throughout all organisms