MICR 271 Final Exam Questions with Correct Answers

MICR 271 Final Exam Questions with Correct
Answers
Replisome Speed

eukaryotic slower - must displace nucleosomes, cell-dependent regulation of replication



multiple initiation sites to compensate

Bacterial Replication Forks

1. Helicase unwinds DNA, lagging strand coated with single stranded binding proteins, RNA

primer synthesized by primase



2. DNA Pol III holoenzyme tethered to DNA by beta clamp, loaded by t-clamp loader



3. 1 Pol III core leading strand synthesis (continuous)



4. 2 Pol III cores lagging strand synthesis (okazaki fragments)



5. Pol I removes primer and fills with DNA, Ligase joins strands

Eukaryotic Replication Fork

1. Helicase (Mcm2-7) + proteins (GINSS, Cdc45, Mcm10) activate unwound DNA, ssDNA

bound by replication protein A



2. Helicase associates wtih primase (synthesizes RNA primer)

,3. Pol ε does leading, Pol δ does lagging (loaded onto DNA by proliferating cell nuclear

antigen, carried to DNA by replication factor C)



4. shorter okazaki fragments generation, Pol δ removes RNA primer and fills with DNA,

ligase seals gap

Family A DNA Polymerases

replication/repair

Family B DNA Polymerases

DNA replication, 3'-5' exonuclease activity

Family C DNA Polymerases

DNA replication

Family D DNA Polymerases

DNA replication

Family X DNA Polymerases

DNA damage repair

Family Y DNA Polymerases

translesion DNA repair

Translesion Repair

insert bases opposite damaged nucleotides or repair dsDNA breaks

Class I virus

,dsDNA genome



mRNA synthesis: transcription using host machinery, translatin mRNA --> proteins



genome replication: using host machinery

Class II virus

ssDNA genome (+ or -)



mRNA synthesis: dsDNA transcribed into mRNA using host machinery



genome replication: dsDNA produced and replicated, strands separated

Class III virus

dsRNA genome



mRNA synthesis: separated into ssRNA, + strand used as mRNA, translated into viral

proteins



genome replication: + ssRNA = template to produce new dsRNA

Class IV virus

+ ssRNA genome



mRNA synthesis: + ssRNA used as mRNA, translated into proteins



genome replication: + ssRNA used to produce - ssRNA = template to produce new + ssRNA

, Class V virus

- ssRNA genome



mRNA synthesis: -ssRNA template to make + ssRNA (mRNA) translated into proteins



genome replication: -ssRNA used to produce + ssRNA = template to produce new -ssRNA

Class VI viruses

Retroviruses



ssDNA reverse transcribed from RNA genome, dsDNA made using DNA Pol



mRNA synthesis: dsDNA integrated into host genome --> mRNA --> protein



genome replication: + ssRNA --> ssDNA by viral reverse transcriptase --> dsDNA into host

genome by integrase --> +ssRNA to produce new genomes

Class VII viruses

Reverse transcribing dsDNA genome



mRNA synthesis: dsDNA --> mRNA by viral RNA Pol --> proteins



genome replication: + ssRNA --> ssDNA by reverse transcriptase --> partially dsDNA

genomes

T4 Phage