DNA and protein synthesis

Created by

amaraa

Cards (14)

what is the genome
the complete set of genes in a cell
what is the proteome  
the full range of proteins the cell is able to produce
what are the two types of RNA
messenger RNA (mRNA) and transfer RNA (tRNA)
what does mRNA act as in protein synthesis
a template strand
describe the structure of mRNA
long, single stranded helix
describe the structure of tRNA
single stranded, clover leaf shaped and contains two attachments sites. one for amino acids and one for its anticodon
what does the anticodon contain
complimentary base sequence to mRNA in triplets
what is tRNA specific to
one amino acid and contains the anticodon for it
describe the production of pre-mRNA
DNA helicase splits the DNA double helix, exposing nucleotid bases
template strands pair with complimentary free RNA nucleotides in the nucleus
RNA polymerase moves along the template strand joining nucleotides together, forming pre-mRNA
when RNA polymerase reaches a stop codon it detaches and pre-mRNA is made
what happens in splicing
introns are removed and functional exons are joined
what is the production of pre-mRNA and splicing called  
transcription
why can mRNA only leave the nucleus after splicing
as it is too large prior and cannot fit in nuclear pores
describe the steps of translation
the mRNA molecule attaches to a ribosome on its start codon
tRNA (with complimentary anticodon sequence) moves to ribosome and pairs with the codon on mRNA strand
the ribosome moves along mRNA strand bringing two tRNA molecules at a time each pairing with corresponding complimentary base pairs on mRNA
amino acids are joined by a peptide bond using an enzyme and hydrolysed ATP as an energy source
the synthesis of the polypeptide continues until a ribosome reaches a stop codon
the polypeptide is complete
how does transcription differ in prokaryotes and eukaryotes
in prokaryotes splicing does not take place as they do not contain introns