DNA structure

Question 1

Beadle and Tatum

Answer 1

proposed one gene-one enzyme theory

Question 2

Avery’s Group

Answer 2

DNA is the genetic material passed from parent to offspring and DNA directs protein synthesis (central dogma)

Question 3

Chargaff’s Group

Answer 3

quantative analysis which was

• A+G =T+ C
• A=T & G=C

Question 4

Franklin (working for wilkins)

Answer 4

DNA X-Ray analysis and concluded that DNA has a right handed twist and the distance acrross the DNA molecule is equal and consistent.
-she also did not know that xrays cause cancer w/o proper protection so she died of cancer. x-rays break chromosomes

Question 5

Watson and Crick

Answer 5

figured out the structure of DNA and wrote a one-page paper describing it. They also won the noble prize with wilkins.
-ball and stick model

Question 6

DNA structure

Answer 6

• nucleotides with nitrogen containing bases with purines (A and G) and pyramidines (T,C, and U)
• pentose sugar
• phosphate group
• alternation withe sugar and phosphate
• weak H-H bonds hold two sides of DNA together and easily breakable for replication
• 2 sides of DNA run antiparelll

Question 7

DNA’s semi conservative replication

Answer 7

occurs by complementary base pairing
-nucleosomes uncoil and histones and other proteins are removes
-H-H bonds are broken and helicases are used
-creates replication forks and bubbles
-

Question 8

DNA polymerase

Answer 8

allows nucleotides to come in

Question 9

helicase

Answer 9

breaks h bonds

Question 10

primase

Answer 10

builds primer

Question 11

primer

Answer 11

is a sequence of nucleotides

Question 12

ligase

Answer 12

hooks together okazaki fragments after primase falls off

Question 13

okazaki fragments

Answer 13

the 5’ to 3’ strands

Question 14

telomeres

Answer 14

“tip of the shoelace”.

• stabilize DNA by creating inert ends
• segments shorten with each nuclear division due to RNA’s primer presence

Question 15

Nucleotide

Answer 15

basic building block of DNA and RNA.

Each nucleotide consists of a base, phosphate and a sugar

Question 16

purine

Answer 16

double ringed organic bases in nucleic acids

Question 17

pyramdines

Answer 17

single ringed organic bases in nuclic acids

Question 18

bubbles and forks

Answer 18

for replication, DNA h-h bonds break for complementary base pairing

Question 19

template

Answer 19

the “2” old DNA pieces are the template for newly forming complementary DNA sequence

Question 20

bidirectional

Answer 20

each side is made continuosly from the origins of replication so 3’ to 5’ and 5’ to 3’

Question 21

leading and lagging strands

Answer 21

• leading strand goes in 5’ to 3’ direction so it continues continously
• lagging strand is the 3’ to 5’ direction and it is discontinous with okazaki fragments

Question 22

replication

Answer 22

• helicase unzips DNA by breaking h bonds
• polymerase allows the nucleotides to come in for complementary base pairing
• primer allows for replication to start
• ligase hooks together okazaki fragments once the primer falls off

Question 23

sister chromatids

Answer 23

replicated chromosomes are composed of 2 sister chromatids