DNA Synthesis and Repair I & II Question and answer 2024
3 views 0 purchase
Course
Hesi
Institution
Hesi
DNA Synthesis and Repair I & II Question and answer 2024
DNA Synthesis and Repair I & II Question and answer 2024
DNA Synthesis and Repair I & II Question and answer 2024
DNA Synthesis and Repair I&II
Study online at
https://quizlet.com/_ftv7s
1.replication: each of 2 DNA parental strands serves as template for
synthesis of complimentary strand.
Result: one DNA molecule made of 1 new, 1 parental strand
2.Cell cycle order: [G1, S, G2] interphase, M --> possibly enter G0
3.G1 phase: "gap" phase. variable length. growth and metabolism. cells
spend most time here.
late G1 - prepare to duplicate chromosomes by producing NT precursors
4.G0: extended G1 phase
stimulated to reenter cycle on appropriate signal
5.S phase:: DNA replication
nucleosomes disassemble as replication fork
advances increase histone, DNA associated ptns
synthesis
DNA + histones double
histones complex with DNA forming nucleosomes behind replication
forks
6.G2 phase: 2nd "gap" phase. preparation for cell
division synthesize tubulin (for making
microtubules of spindle)
7.M phase: mitosis: cell divides.
each daughter cell gets exact copy of parental DNA
includes segregation of replicated DNA and
cytokinesis
8.G0 phase: no replication
9.replication fork: site where replication is occurring. (replication origin -
specific sequences. eukaryote genome may have 1000's, bacteria have
one, plasmids have separate origin)
- parental strands separate/unwind before fork
- new strands paired with parental strands behind fork
- replication proceeds into the fork from the origin
10.helicases: separate the DNA strands and unwind the parental duplex
- at replication fork
11.topoisomerases: break phosphdiester bonds and rejoin
them relieve supercoiling of parental duplex by
unwinding
- e.g. gyrase in bacterial cells
- at replication fork
12.singe-stranded binding proteins: prevent parental strands from
reannealing protect from enzymes that cleave ssDNA
, DNA Synthesis and Repair I&II
Study online at
- at
replication fork
https://quizlet.com/_ftv7s
13.DNA polymerase directionality: copies parental 3'-->5' template
(leading strand). replication of 5' to 3' discontinuous.
- adds new monomers to 3' end of polymer only
, DNA Synthesis and Repair I&II
Study online at
https://quizlet.com/_ftv7s
14.deoxyribonucleoside triphosphates: precursors for new DNA strand
synthe- sis
15.Okazaki fragments: discontinuously formed segments of DNA from
synthesis from 5' to 3' parent
16.DNA ligase: joins okazaki fragments with phosphodiester bond
- (btw DNA pol I 5'P of replaced DNA NT of RNA primer and
- DNA pol I 3' OH of the initial NT added to
primer) uses ATP
17.initiation: short primer containing ribonucleotides attached at 3' end.
- DNA polymerase cannot initiate
- primer later removed and replaced by deoxyribonucelotides
18.telomeres: ends of linear chromosomes
19.telomerase definition/function/components: RNA dependent DNA
poly- merase
carries its own RNA template complimentary to telomere sequence
use overhang as primer, own RNA as template -- lengthens 3' end.
repeat several times. then primase binds
synthesizes telomeres
- b/c at lagging strand
- primase can't lay down primer
- RNA at end of chromosome is degraded
--> shorter 5' end, 3' overhang
20.homologous recombination: - similar strands of adjacent double-
stranded DNA interact
-->inter-stranded exchange of bases
- basis for crossing over and gene conversion (during meiosis...)
- many enzymes involved: ssB ptns, DNA pol, ligase, gyrase, several
recombination specific ptns
- occurs through variety of models
- produces new ptns or variations of ptns that may increase survival rate
of species.
21.DNA replication: semiconservative: daughter chromosome
contains one parental strand and one newly synthesized
complementary strand
- parents conserved, but not together
22.DNA pol I: in Prokaryotes
filling of gap after removal of RNA
primer DNA repair
Removal of RNA primer in conjunction with RNAse
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller examiner123. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $17.99. You're not tied to anything after your purchase.
