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Flashcards in Replication and Transcription Deck (47)
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1

Protein machine that performs replication is called a

Replisome

2

Replisomes begin at _____

Origins

3

Replication forks

Sites of new DNA syntehsis

4

DNA polymerase vs. RNA polymerase

DNA polymerase has to have a short RNA to start...DNA cannot start polymer

5

What is proofreading activity of DNA polymerase

3' to 5' exonuclease activity

6

Why do drugs like AZT work?

Viral reverse transcriptases lack proofreading ability...once substituted, it kills the virus

7

Leading vs. lagging strand

Leading continuous
Lagging - okazaki and discontinuous

8

WHat makes short RNA primer?

RNA primase...on boht leading and lagging strand

9

Replication promotes ____ in front and ______ behind

Positive supercoiling in front (overwound)
Negative supercoiling behind (unwound )

10

Helicase

Unzips double helix

11

Topoisomerases

Relieve supercoil tension

12

Type 1 topoisomerases

Cut one of the strands and allow it to make a turn...then re-lligate

13

Type 2 topoisomerase

Cut both stands and pass another stand through...then re-ligate the two cut strands

14

Etoposide

Interferes with Topo 2 function...this inhibits replication during rapidly dividing cells

Locks the enzyme onto the DNA...triggers apoptosis

15

5-FU

5-flurouracil
Converted to FdUMP which inhibits thymidylate synthase...results in lower levels of dTMP (made to use dTTP) and less replication

16

Thymidylate synthase reaction

dUMP to dTMP (leads to dTTP which leads to replication)

17

Werner Syndrome

Mutation in replication helicases
Rapid-aging disease

18

Errors in replication that lead to nucleotide repeats that lead to repeat number increasing

Nucleotide expansion diseases

19

When and why do nucleotide expansions occur?

When trinucleotide repeats form hairpins...due to self-complpimentary nature

20

Nucleotide expansion occurs if

Hairpin forms on new DNA strand...DNA polymerase is "snapped back"

21

Nucleotide deletion occurs if

Hairpin forms on template DNA strand...DNA polymerase jumps over gap

22

If expansion or deletion is not detected,

It will be replicated and become permanent...this means even a higher chance that more will occur

23

Spinocerebellar ataxia

Nucleotide expansion disease
CAG expansion

24

Anticipation

Children of people with nucleotide expansion syndromes often show symptoms at an earlier age

25

Child nucleotide repeat length vs. parents

Longer

26

RNA has same sequence as ____ and completementary to _____

Top strand
Bottom strand

27

Transcription is regulated by

Proteins that bind to gene promoters and regulate whether RNA polymerase can bind

28

Activators

Help RNA polymerase bind

29

Repressors

inhibit RNA polymerase from binding

30

Proteins that bind promoters recognize

Things like TATA CAAT and GC boxes