Molecular Genetics: DNA Replication

Question 1

DNA is __% this and __% this

Answer 1

50% genetics
50% protein

Question 2

The nature of genetic material (5)

Answer 2

1.) DNA has to be able to replicate
2.) Stable (doesn’t change all the time)
3.) Contains information
4.) Transmit and control information in the cell
5.) Be able to change in a controlled way to enable survival of species by variations

Question 3

Feulgen, what he discovered, and when

Answer 3

A scientist who created a stain which stains chromosomes to be able to see how they work

1912

Question 4

Griffith, what he discovered, and when (7)

Answer 4

-1920
-2 forms of pneumonia bacteria
-S shape with shiny disks
-R shape with rough disks
-Injected mice with S they died
-Injected mice with R they lived
-If they heated the s cells then they lived

Question 5

Conclusion of Griffiths expirment

Answer 5

The molecules the S cells released when killed could change living R cells into S cells. He called this transformation.

Question 6

Avery-MacLeod-McCarty

Answer 6

Took Griffith’s experiment one step forward and figured out that it was DNA that caused the bacteria to turn into an infective form not protein

Question 7

Hershey Chase experiment what and when (3)

Answer 7

-1852
-The tails on Bacteriophage touch a cell and they all glue onto it and the tail compresses into the cell and injects the DNA into the cell
-They died the Protein Sulfur red and the DNA Phosphorus green. They then looked to see if either colour was inside the cell after centrifugation.

Question 8

Erwin Chargaff what and when (4)

Answer 8

-1950
-went through a bunch of different organisms
-Looked at the ratio of DNA AGCT foreach organism
-Chargaff’s ratios mean that CG pair together and AT pair together

Question 9

Rosalind Franklin (2)

Answer 9

-taking crystals of DNA and taking x-rays of them
-characteristic pattern showing the structure of DNA was a double-helix

Question 10

Watson and Crick what and when (4)

Answer 10

-1953
-Stole Franklins work
-built models of what DNA look like
-realized the pairs were the same size and were put together as a ladder

Question 11

3 components of Nucleic acids

Answer 11

-Pentose Sugar (ribose of deoxyribose) made of Oxygen, Carbon, and Hydrogen
-Phosphate group
-Nucleotide base

Question 12

What is the difference between ribose and deoxyribose?

Answer 12

Deoxyribose has a missing OH-

Question 13

4 characteristics of nucleotides

Answer 13

-Have 4 bases (cytosine, guanine, thymine, and adenine)
-3 phosphate groups on the side
-ATP is one of the bases in DNA
-ADP has two phosphate groups

Question 14

What’s on the bottom

Answer 14

Question 15

two groups of nucleotide bases

Answer 15

purines and pyrimidines

Question 16

Purines

Answer 16

Adenine and Guanine
Bigger structure

Question 17

Pyrimidines

Answer 17

Cytosine, Thymine, Uracil
Smaller structure

Question 18

How many bonds are on a GC pair

Answer 18

3 hydrogen bonds

Question 19

How many bonds are on a AT pair

Answer 19

2 hydrogen bonds between them

Question 20

1’ end

Answer 20

Where a base attaches

Question 21

3’ end

Answer 21

-where the most important hydroxyl group is
-DNA can only build off this end

Question 22

5’ end

Answer 22

Has an O group attached

Question 23

5 characteristics of DNA

Answer 23

-Very stable
-Found in the Nucleus
-Only found outside the nucleus during replication, and in chloroplast and mitochondria
-Each cells contains all the genes for the organism
-Hard to break up

Question 24

Meselson-Stahl (5)

Answer 24

-Proposed 3 models of DNA replication
-Semi-Conservative is the way replication works
-Each stand is pulled apart and then a new copy attaches to the other side
-They used E.coli and put it in N15 which is heavier and N14
-They crossed the N15 generation with N14 and did it multiple times and each time there was more N14 present than N15

Question 25

6 proteins involved in DNA replication

Answer 25

helicase
topoisomerase
DNA polymerase I and III
DNA primase
ligase
single-stranding binding proteins

Question 26

Helicase

Answer 26

unwinds DNA helix and puts stuff on it so the strand don’t glue back together

Question 27

Topoisomerase

Answer 27

Relieves the overtwisting of the DNA ahead of the replication fork

Question 28

DNA polymerase III

Answer 28

Assembles DNA chain on both sides

Question 29

DNA polymerase I

Answer 29

Replaces the primer fragments with the correct DNA

Question 30

ligase

Answer 30

Seals the nicks left between DNA where the RNA fragments used to be

Question 31

single-stranding binding proteins

Answer 31

Stabilizes DNA in single-chain form

Question 32

Okazaki fragments

Answer 32

The fragments of DNA placed in the lagging strand

Question 33

Which way is DNA replicated

Answer 33

from the 3’–> 5’ end

Question 34

What happens to the phosphate when DNA is being put together

Answer 34

When DNA is being put together the base being laid has 3 phosphates attaches. One stays and the other two push off and go to the 3’ end.

Question 35

Proof reading

Answer 35

Depends on the ability of DNA polymerase to reverse and remove mismatched bases

Question 36

What happens during the DNA repair mechanism

Answer 36

-Polymerase I recognizes the mispaired bases
-Remove a section of DNA with the mispaired, and replace it with a new section

Question 37

The template strand is…

Answer 37

continuous

Question 38

the new strand…

Answer 38

has nicks left in it

Question 39

How does DNA replication explain cancer in older people

Answer 39

they have had more replications which means more time for replication errors to occur

Question 40

Rolling circle replication (4)

Answer 40

1.) A donor cell duplicates with a recipient
2.) A strand of f-factor breaks and moves through a conjunction bridge
3.) DNA replication of the f-factor is continuous in the donor and discontinuous in the recipient
4.) One done they are completely identical copies