Gene expression and proteins L7 Flashcards
gene=
fundamental unit of heritable, genetic information
what does a protein coding gene require
all the nucleotide sequence necessary to produce a mature messenger RNA (mRNA)
what happens between pre-mRNA and mRNA
splicing
where does transcription and splicing happen
in the nucleus
where does translation happen
cytoplasm
what controls where a gene is transcribed
promoters and regulatory sequences
what enzyme is a gene transcribed by
RNA polymerase
what binds to promoters and regulatory sequences
transcription factors (proteins)
which way does RNA polymerase move along the template DNA
3-5
which side does RNA add nucleotides to the growing chain
3
what is transcribed into pre-mRNA
exons and introns
what is splicing
the introns form a loop and are spliced out
what 2 maturations happen to mRNA
capping
polyadenylation
what is capping
a cap structure is added to the 5 end of mRNA shortly after transcription
polyadenylation=
at the 3 end of mRNA poly-A polymerase adds 100-300 adenine residues forming a poly-A-tail
what can destabilise mRNA
microRNAs
what do microRNAs do
destabilise and inhibit translation of mRNA
what is the effect of microRNAs on mRNA called
RNA-induced silencing
what does it mean that the genetic code is degenerate
most amino acids are coded for by more than one codon
what is the initiating codon
AUG- methionine
initiator-stop codon=
open reading frame
what do transfer RNA molecules do
carry amino acids with anticodon triplets at the opposite end
what do stop codons do
release factors causing the ribosome to fall apart
common post-translation modification=
glycosylation
phosphoylation
