DNA replication

Question 1

What is the the sequence of the repeating telomere at the end of DNA for humans

Answer 1

TTAGGG

Question 2

What was the name of the woman who did much of the research in the area of x-ray crystallography for DNA that led to Watson and Crick’s discovery, but received almost no credit?

Answer 2

Rosalind Franklin

Question 3

What two men were responsible for proving that DNA replicates semi-conservatively?

Answer 3

Messelson and Stahl

Question 4

In what year did Watson and Crick receive the Nobel Prize?

Answer 4

1962

Question 5

Who received the Nobel Prize with Watson and Crick?

Answer 5

Maurice Wilkins

Question 6

In what year did Watson and Crick discover the structure of DNA?

Answer 6

1953

Question 7

What two nitrogenous bases are purines?

Answer 7

adenine and guanine

Question 8

What two nitrogenous bases are pyrimidines?

Answer 8

cytosine and thymine

Question 9

What is the name of the noncoding regions at the end of each DNA strand?

Answer 9

Telomeres

Question 10

What is the name of the enzyme that extends the length of the telomeres?

Answer 10

telomerase

Question 11

What happens to the little strand that is left over after the replication has taken place?

Answer 11

It performs a hairpin turn and joins to the bottom strand to prevent the sticky bit from attaching to something else

Question 12

What are the two methods that are used to proofread the DNA?

Answer 12

DNA polymerase III and nucleotide excision repair

Question 13

What is the method of attack for nucleotide excision repair?

Answer 13

The enzymes search for abnormalities in the shape of the helix, and when found, excise the section around the error, and then DNA polymerase III fills in the section with the proper nucleoides

Question 14

What mechanism does DNA polymerase use to go backwards and proofread the strand?

Answer 14

3’-5’ exonuclease

Question 15

What is a nucleotide called before it is added to the DNA strand?

Answer 15

nucleoside triphosphate

Question 16

What determines the 3’ end?

Answer 16

the OH group at the end of the deoxyribose sugar

Question 17

What determines the 5’ end?

Answer 17

The phosphate group

Question 18

What is the length of one full revolution of DNA?

Answer 18

3.4 nm

Question 19

What is the length between two nucleotides in DNA

Answer 19

.34 nm

Question 20

In what direction does the replication strand always travel?

Answer 20

5’-3’

Question 21

What are three steps in cloning genetic DNA in a bacterial plasmid?

Answer 21

1. Take the DNA with the sequence you are interested in and chop it up
2. Insert the different pieces into different bacteria
3. Find the bacteria that has the characteristic of the sequence you were after, isolate it and grow a bunch

Question 22

What are restriction enzymes?

Answer 22

They cut DNA at certain sequences with a certain shape (sticky or blunt)

Question 23

summarize Polymerase Chain Reactions (PCR)

Answer 23

A procedure that uses different levels of heat to denature the strands, then anneal the primers, extend the primers, and replicate the DNA. It can be used to replicate large amounts of a certain sequence in a very short period of time