DNA

Question 1

What is the 5’ end? 3’ end? how is DNA read?

Answer 1

5'= free phosphate attached to 5' carbon 
3'= OH group attached to 3' carbon 

Read from 5’ to 3’

Question 2

What is a ribose? Deoxyribose?

Answer 2

1. Ribose:5 carbon ring with OH at 2’ carbon.

2. Deoxy: H at 2’ carbon

Question 3

What is a nucleoside? Nucleotide?

Answer 3

Side=bast+ribose/deoxy

Tide=Phosphorylated nucleoside.

Question 4

How are bases linked within a strand? Complement bases?

Answer 4

Bases in a strand are linked by Phosphodiester bonds .

Complement bases are liked by H bonds.

Question 5

What can denature DNA?

Answer 5

Alteration of PH, Increased heat, DNA replication.

Question 6

What is Tm?

Answer 6

The temperature at which 1/2 the DNA denatures.

Question 7

What did the Hershey Chase experiment do?

Answer 7

Showed that DNA contained genes, not protein.

Question 8

What is a nucleosome?

Answer 8

Is tightly wound DNA around histones.

Question 9

What did the Meselson Stahl experiment show?

Answer 9

Showed that DNA synthesis is semi-conservative.

Question 10

Describe the steps in DNA synthesis with enzymes. (DNAa, Helicase, binding proteins, Topoisomerase, primase, DNA pol, Ligase).

Answer 10

1. DnaA initiation factor that promotes denaturation of DNA at origin of replication.
2. DNA helicase unzips at replication fork.
3. ssDNA binding proteins keep ss stable.
4. Topoisomerase remodels DNA to relieve coiling.
5. Primase synthesizes RNA primer.
6. DNA polymerase replicate DNA in a 5’ to 3’ fashion
7. Ligase links DNA back together.

Question 11

What is the main DNA polymerase? What can DNA polymerase I do?

Answer 11

DNA poly III main one.

DNA poly two can remove RNA primer and replace it with DNA after replication is finished.