How Genes direct the production of proteins Flashcards
what is mRNA and what is it used for
messenger RNA. translated into proteins
what is tRNA and what is it used for
transfer RNA. transfer amino acids to the growing peptide chain
what is rRNA and what is it used for
ribosomal RNA. encodes ribosomal proteins
what is microRNA used for
block translation of specific mRNAs and regulate gene expression
what are siRNA used for
small interfering RNA. turn off gene expression by directing the selective degradation of mRNAs
what is snoRNA and what is it used for
small nucelolar RNAs. process and chemically modify rRNAs
what are scaRNAs
small cajal RNAs. modify snoRNAs and snRNAs
what are noncoding RNAs used for
telomere synthesis, X- chromosome inactivation and protein transport into the ER
what is the order of abundant RNA type
rRNA > tRNA > mRNA
what are most protein coding genes transcribed as
RNA polymerase II
how does transcription start mechanism
TBP/TFIID binds to TATA box
- TFIIB binds to complex
-TFIIB binding leads to other factors binding and eventually RNA polymerase II
can RNA fold on itself
yes
what does TFIIB recognize and
recognizes BRE element and accurately positions RNA polymerase at the start site of transcription
what genes does RNA polymerase I work with
rRNA
what genes does RNA polymerase II work with
all protein coding genes, snoRNA, miRNA, siRNA, and most snRNA
what genes does RNA polymerase III work with
tRNA, rRNA, some snRNA
what are the order of events in mRNA processing
-capping
-splicing
-editing
-polyadenylation
-transport
what performs RNA splicing
spliceosome
what is the spliceosome made of
snRNAs with 7 protein subunits to form a SNP
what snRNAs are involved in splicing
U1, U2, U4, U5
what do the snRNAs do
provide proper base pairing with the mRNA
how does splicing occur
adenosine residues in the intron sequence undergoes nucleophilic attack at junction of intron and exon
how many genes does the human genome have
20,000-25,000
how many proteins does the human proteome have
250,000
