DNA Replication

Question 1

Griffith

Answer 1

Pneumonia bacteria

Transformation of genes(?) by an external thing

Question 2

Bacteriophages

Answer 2

Viruses that infect bacteria

Question 3

Hershey and Chase

Answer 3

Radioactive tests

DNA left in cell

Question 4

Chargaff’s Rule

Answer 4

A=T and C=G

Question 5

DNA

Answer 5

Polymer of nucleotides

Nitrogenous base, a sugar, a phosphate group

Question 6

Watson and Crick

Answer 6

Double helix model

DNA has two antiparallel sugar phosphate backbones

3’ and 5’ ends

Question 7

Purine

Answer 7

Double ring

A and G

Binds with pyrimidine

Question 8

Pyrimidine

Answer 8

Single ring

T and C

Binds with purine

Question 9

Double Helix

Answer 9

Held together by H bonds between bases

A-T have 2 h bonds
GC have 3 H bonds

Question 10

Arthur Kornberg

Answer 10

Discovered how DNA is synthesized

• Nucleotides
• Template
• DNA polymerase
• Mg 2+ (optimizes activity)

Question 11

Replication

Answer 11

Each strand acts as a template for building a new one

Parent reads from 3’ to 5’ end

Build daughter starting at 5’ but adding nucleotides on the 3’ end

Parent unwinds, builds two daughters

Question 12

Semi-conservative

Answer 12

Each daughter has one parent strand

Question 13

Sites of Origin

Answer 13

Where DNA replication begins

Hundreds/thousands

Question 14

Replication Fork

Answer 14

Point at which the parent strand is not unzipped

Question 15

Replication Bubble

Answer 15

Area where DNA replication is occurring

Daughters strands are being formed

Question 16

Steps of Replication

Answer 16

• Initiator proteins
• Topoisomerase
• Helicase-
• Binding proteins stabilize
• Primase-
• DNA Polymerase III-
• DNA polymerase I-
• DNA Polymerase II-
• Ligase-

Question 17

Topoisomerase

Answer 17

Prevents over twisting of DNA

Question 18

Helicase

Answer 18

Unwinds helix

Question 19

Primase

Answer 19

Adds RNA primer

Question 20

DNA Polymerase III

Answer 20

Adds nucleotides to 3’ end of daughter

Question 21

DNA Polymerase I

Answer 21

Replaces RNA primer

Question 22

DNA Polymerase II

Answer 22

Proofreads

Question 23

Ligase

Answer 23

Glues segments together

Question 24

Leading Strand

Answer 24

Synthesizes daughter continuously

Moving toward replication fork

Only needs one set of enzymes

Question 25

Lagging Strand

Answer 25

Created in Okazaki fragments Joined together with ligase Moves away form replication fork

Question 26

Primers

Answer 26

Initiate DNA synthesis with RNA or DNA primer Short nucleotide strand 1 primer for the leading strand Primer at each Okazaki fragments for lagging strand

Question 27

Thymine Dimers

Answer 27

Caused by exposure to UV light Adjacent thymines become covalently linked

Question 28

Telomere

Answer 28

Junk DNA at end of strand, non-coding sequence Chromosomes get shorter with each replication Postpones erosion of genes

Question 29

Telomerase

Answer 29

Adds telomeres to the ends of DNA Prevents loss of genes