How many enzyme activities are expressed by and involved inthe movement of retro-homing elements in the Type II introns? Whatare the activities? How do they work?
A.
Two; the spliced intron expresses an endonuclease, which cutsthe target DNA sequence for reverse splicing of the RNA intron intothe DNA sequence, then a reverse transcriptase synthesizes thecomplementary DNA sequence using the intron as template
B.
Four; the spliced intron expresses an endonuclease, which cutsthe target DNA sequence, then a special recombinase introduces theRNA sequence into the target DNA, a reverse transcriptasesynthesizes the complementary DNA sequence using the intron astemplate, and then an RNAse activity removes the RNA sequence whilethe host DNA polymerase replaces the RNA with a DNA sequence.
C.
Three; the spliced intron expresses an endonuclease, whichcuts the target DNA sequence, then a special recombinase introducesthe RNA sequence into the target DNA, finally, a reversetranscriptase synthesizes the complementary DNA sequence using theintron as template.
D.
One; the spliced intron is incorporated into the target DNA byhomologous recombination between the intron RNA and the target DNAcatalyzed by a special recombinase expressed by the intron.
2.
Aging cells carry lower levels of the enzyme Telomerase,whereas cancer cells carry high levels of this enzyme. Whatintracellular molecule is its target? What does it do to thetarget? Does it harbor a prosthatic group to complete its action?What is it?
A.
DNA, extends the 3’-end, Yes, RNA
B.
RNA, extends the 3’-end, No, None
C.
RNA, cleaves into 21-base oligonucleotides, Yes, RNAse bindingprotein
D.
DNA, removes nucleotides from the 3’-end until it reaches thechi sequence, Yes, a protein by the name Rec A
E.
Protein, cleaves at the C-terminal of Aspartic acid, Yes,RNA
3.
Telomeres are beneficial to the target because of a particularreason:
A.
they are protein complexes that stabilize a chromosome
B.
they are protein complexes that stabilize a chromosome
C.
telomeres are 3’ extensions, which protect a chromosome fromexonuclease digestion
D.
telomeres are covalently linked molecular caps that protectboth ends of a chromosome
E.
telomeres are 5’ extensions that stabilize a chromosome fromendonuclease digestion
these are the only information I have
1. How many enzyme activities are expressed by and involved inthe movement of retro-homing elements in the Type II introns? Whatare the activities? How do they work?
One; the spliced intron isincorporated into the target DNA by homologous recombinationbetween the intron RNA and the target DNA catalyzed by a specialrecombinase expressed by the intron.
2. Aging cells carry lower levels of the enzyme Telomerase,whereas cancer cells carry high levels of this enzyme. Whatintracellular molecule is its target? What does it do to thetarget? Does it harbor a prosthatic group to complete its action?What is it?
DNA, extends the 3’-end,Yes, RNA
What intracellular molecule is its target? DNA
What does it do to the target? extends the 3′ end
Does it harbor a prosthatic group to complete its action?Yes
What is it? RNA
Telomerase add repeat sequence of telomere at 3’end of DNA whichare complementary bases to the RNA template
3. Telomeres are beneficial to the target because of aparticular reason:
telomeres are covalentlylinked molecular caps that protect both ends of achromosome
They protect both the ends of a chromosome
