translation and transcription Flashcards
what is the function of a ribosome?
● mRNA associates to ribosome
● allows tRNA with anticodons to associate
● catalyses formation of peptide bonds between amino acids
● moves along mRNA to next codon
what is produced by transcription?
mRNA
where does transcription take place?
in nucleus
what are the 6 steps of transcription?
● hydrogen bonds are broken by an enzyme helicase
● one strand acts as a template
● free RNA nucleotides in nucleus align by complimentary base pairing
● uses uracil instead of thymine
● RNA polymerase joins nucleotides up forming phosphodiester bonds - forming pre-mRNA
● introns are removed by splicing by enzymes
● mRNA leaves nucleus and goes to ribosome
what does transcription result directly in the production of in prokaryotes?
● mRNA from DNA
● no pre-mRNA (splicing skipped)
● as no introns
what is produced by translation?
proteins / polypeptides
where does translation take place?
● in cytoplasm
● on ribosomes
what are 6 steps of translation?
● mRNA associates to the ribosome
● ribosomes finds the start codon (AUG)
● tRNA brings a specific amino acid
● tRNA has anticodon that is complementary to codon on mRNA
● ribosome moves mRNA to next codon
● process repeats and amino acids are joined by a peptide bond in condensation reactions
● requires ATP
