Bio exam 4 ch 14

Question 1

Avery, Macleod, Marty contributions

Answer 1

DNA is the transforming material

Question 2

Griffith contributions

Answer 2

Concluded something passed from heat killed S cells to R cells, transforming them

Question 3

Hershey and Chase contributions

Answer 3

Showed that DNA is the genetic material, not protein

Question 4

Watson and Crick contributions

Answer 4

Solved the 3d structure of DNA

Question 5

Chargaffs contributions

Answer 5

Amount of A=T
Amount of G=C

Question 6

Franklins contributions

Answer 6

X ray suggested a helical/spiral molecule

Question 7

Evidence that helped Watson and crick

Answer 7

-DNA was known to be a polymer of nucleotides
-Nucleotides consist of: Deoxyribose sugar, phosphate group, nitrogenous base (pyrimidine, purine)

Question 8

Pyrimidine

Answer 8

-Nitrogenous base
-1 ring
-C and T

Question 9

Purine

Answer 9

-2 rings
-A and G

Question 10

Carbons and what they have on them- deoxyribose sugar

Answer 10

-C1: Nitrogenous group
-C3: OH group
-C4: CH2
-C5 (the C in CH2): Phosphate

Question 11

DNA structure

Answer 11

-Right handed helix
-Double stranded
-Each strand is a polymer of nucleotides, with adjacent nucleotides linked by phosphodiester bonds
-Strands are antiparallel held together by hydrogen bonds
-Uniform diameter

Question 12

Grooves in DNA

Answer 12

Proteins bind DNA at grooves

Question 13

DNA structure functions

Answer 13

-Storage of genetic information
-Replication during cell division by complimentary base pairing
-Changes in DNA sequence
-Expression of the coded information as the phenotype

Question 14

Semi conservative replication

Answer 14

-Each of the 2 new DNA molecule get part of the original one

Question 15

DNA replication

Answer 15

-DNA helix unwinds
-Parental strands serves as a template
-New strands synthesized in 5 to 3
-New nucleotides are added to 3 end
-Begins and organ of replication (more in eukaryotes)

Question 16

Helicase

Answer 16

-Unzips DNA at origin of replication

Question 17

Primase

Answer 17

-Makes RNA primer
-DNA polymerase III used primer to syntehsize
-Needs this bc it needs a free 3 end and can’t do it without primase

Question 18

Topiosomorase

Answer 18

-Relieves tension by creating a nick
-Prevents overwinding

Question 19

Single strand binding proteins

Answer 19

-Keeps strands open and stabilized

Question 20

DNA polymerase I

Answer 20

-Replaces RNA primer with DNA

Question 21

DNA ligase

Answer 21

-Seals nicks

Question 22

Leading strand

Answer 22

-Continuous synthesis towards fork

Question 23

Lagging strand

Answer 23

-Discontinuous synthesis opposite direction of fork
-Okazaki fragments

Question 24

5 prime vs 3 prime end

Answer 24

-5: phosphate group is attatched
-3: OH group is attached

Question 25

Proofreading

Answer 25

DNA polymerase reconizes and removes incorrectly paired nucleotides

Question 26

Mismatch repair

Answer 26

-After replication, repair proteins scan for mismatched bases and replace them
-If not caught, causes mutations

Question 27

Nucleotide excision repair

Answer 27

-Fixes thymine dimers caused by UV light