Lecture 13 (part two of chapter 15) Flashcards
What RNA polymerase transcribes rRNA?
Pol I
Eukaryotes have ____ RNA polymerases
three
What RNA polmerase transcribes mRNA and some snRNA?
pol II
What RNA polymerase transcribes tRNA and some other small RNAs?
pol III
Each RNA polymerase recognizes its own _____
promoter
RNA Pol I promoters are _____ specific
species
RNA Pol II promoters consist of a ____ _______ that can be composed of a number of elements
core promoter
T or F: The TATA box is included in the core promoter
True
Where RNA Pol III promoters found?
within the gene itself
Where is the initiation of transcription at?
Pol II promoters
T or F: RNA pol II requires a series of transcription factors
True
What are elongation complex factors coordinated by structural features called?
carboxyl terminal domain (CTD)
In eukaryotes, the primary transcript must be modified to become ______ mRNA
mature
How is the primary transcript modified to become mature mRNA?
-addition of 5’ cap
-addition of a 3’ poly-A tail
-removal of introns
Why is the addition of a 5’ cap extremely important?
it provides RNA stabiity
What is the process called where GTP is added to 5’ end, with GTP modified by addition of methyl group, called methyl-G cap
addition of a 5’ cap
What is the 3’poly-A tail created by?
poly-A polymerase
Many eukaryotic genes contain sequences that are ____ represented in mRNA
not
What are the non-coding sequences called?
introns
What are the sequences that will be translated called?
exons
Eukaryotic cells deal with introns by cutting and putting back together the _____ ______ to produce _____ mRNA
primary transcript, mature
What is the putting back together the primary transcript to produce mRNA called?
pre-mRNA splicing
What particles recognize the intron-exon boundaries?
small ribonucleoprotein particles
snRNPs cluster with other proteins to form _______
spliceosome
What structure is responsible for removing introns via splicing?
spliceosome
T or F: there is no observed rule governing the number of introns per gene, or the size of introns and exons
True
What theory explains the presence of introns by suggesting exons are functional domains and intron-exon arrangements represent shuffling of those domains over evolutionary timescale?
exon shuffling
What is all the RNAs produced from a genome called?
transciptome
What are all the proteins produced from a genome called?
proteome
T or F: the ratio of genes o transcripts to proteins is 1:1:1
FALSE
What process is of a single primary transcript being spliced into different mRNAs by including different sets of exons being spliced into different mRNAs by including different sets of exons
alternative splicing
What process can account for deviation from balanced ratio?
alternative splicing
What process can greatly increases the number and variety of proteins encoded in the cell nucleus without increasing the size of the genome?
alternative splicing
What is a key macromolecular machine involved in translation that requires interaction with mRNA and tRNA to synthesize proteins
Ribosomes
What adds amino acids to the acceptor stem of tRNA?
aminoacyl-tRNA
What contains three nucleotides complementary to mRNA codons?
anticodon loop
What is the 2d structure of tRNA called?
cloverleaf
At what prime is the acceptor end in tRNA?
3’