Nucleic Acids

Question 1

Identify the purine bases and pyrimidine bases and the number of H bond each pair make

Answer 1

Purine: Adenosine and Glycine
Pyrimidine: Thymine Cytosine and Uracil
AT= 2 H bonds
CG= 3 H bonds

Question 2

What are the components of deoxynucleotides?

Answer 2

Nitrogenous base
Phosphate backbone
Deoxyribose

Question 3

What are the components of nucleotide triphosphates?

Answer 3

Ribose
Phosphate
Nitrogenous base

Question 4

Explain the need for H bonding within a single stranded tRNA and rRNA

Answer 4

Stability and protection from accidentally being viewed by nucleases as viral RNA

Question 5

How do DNA binding proteins interact with DNA helix?

Answer 5

Histones are basic proteins that interact with the negative phosphodiester backbone of DNA.
Acetylating histones will make the histone less positive thus loosening the DNA coil from them.

Question 6

How is ribose different than deoxyribose?

Answer 6

Ribose has a -OH group on carbon #3

Question 7

What is epigenetics?

Answer 7

The changing of function and not the sequence such as methylating a gene to deactivate it

Question 8

Describe the mutations which result from deamination of nucleotide bases

Answer 8

Cytosine deaminates to Uracil
Guanine deaminates to xanthine
Adenine deaminates to hypoxanthine
Thymine does not deaminate

Question 9

Describe the mutations resulting from spontaneous tautomerization of nucleotide bases

Answer 9

Tautomerization: electrons and hydrogens move around an atom

Problems such as AC pairing may arise

Question 10

Explain how topoisomerases and histones create supercoiling of DNA

Answer 10

Topoisomerases regulate supercoiling in the DNA which affects histone-DNA interactions