RNA metabolism Flashcards
(34 cards)
RNA is the only molecule that acts as a ____ and a ____
catalyst and a genetic transmitter
purines are
Adenine and Guanine ( two ringed)
Pyrimidines are _______
cytosine and thymine and Uracil ( one ringed)
which pair has 3 H-bonds
Guanine and cytosine
what is required for the syntheses of RNA
DNA templete strand all 4 ribonucleosides (ATP, GTP, UTP and CTP) which are the precursors for the nucleotides for RNA and MG2+
which way does it build the RNA strand
5 prime -3 prime
is a primer required for RNA polymerase
no
what initiates transcription
sigma factor and RNA polymerase
What is NUS A
protien that helps RNA pol to move further down the gene, used for elongation
explain the sigma or transcription cycle
RNA and sigma factor come together to bind at the promotor, sigma leaves, NUs A comes in and helps RNA poly move down the gene, elongation, nus a and RNA poly leave and termination
describe the 3 types of RNA polymerases
poly 1: syntheses of rRNA
poly 2: mRNA
poly 3: tRNA
how many subunits is poly 2 made of in humans
12
explain 5’ cap
a residue of 7-methylguanosine linked to the 5’-terminal residue through an unusual 5’-5’-triphosphate linkage
how is 5’ cap formed
condensation of a molecule of GTP
which genes do not have introns
histones
self splicing
no ATP- in mitochondria and nucleus genome
what identifies the 5’ end of an intron that can undergo splicing
U-A
what identifies the 3’ end of an intron that can undergo splicing
G-U
the what on the GTP acts as a nucleophile and attacks the 5’ end of U-A?
OH
the OH on GTP attacks the what bond on the 5’ end on an intron?
U-A
snRNAs
small nuclear RNAs
the large protein complex that does the splicing
splicomere
which of the 5 spurps are missing
U3
whats unique about group 1 and 2 introns ( there asre four groups )
no enzymes required
