FINAL EXAM CHAPTER 33 DNA and RNA

Question 1

What do the Nucleosides, Nucleotides and Nucleic acids function as?

Answer 1

-Vitamins
-Coenzymes
-Energy Carriers
-Second Messengers
-Catalysts
-Genetic information transmitting and storage materials

Question 2

What does a purine look like ?

Answer 2

A hexagon that has a pentagon attached to it

Question 3

What does Pyrimidines look like?

Answer 3

A hexagon

Question 4

What Nitrogenous bases have a purine structure and what is the structure like?

Answer 4

Adenine : has a standard purine and a NH2 at the top
Guanine : standard purine and a H2N on the left and a oxygen double bonded to the top

Question 5

What Nitrogenous bases have a Pyrimidines structures and what is the structures like?

Answer 5

Cytosine : Standard pyrimidine and a NH2 binded to the top

Uracil : standard pyrimidine and a oxygen double bonded at the top and bottom left

Thymine : standard pyrimidine and a oxygen double bonded at the top and bottom left and a CH3 binded to the top right

Question 6

How does the numbering and structure of ribose and deoxyribose differ?

Answer 6

Numbering are the same and the structure is the same except at carbon 2 the ribose has an OH and the deoxyribose has a H

Question 7

What is the Beta glycosidic linkage?

Answer 7

The bond between the anomeric carbon and the nitrogen.

Question 8

What is the structure of a Nucleotide?

Answer 8

Ribose-5’-phosphate+Nitrogenous base

Question 9

What is the structure of a Nucleoside?

Answer 9

Ribose with a 1’ nitrogenous base

Question 10

What is the structure of a Nucleic Acids ?

Answer 10

-Long
-Linear polymers constructed from four types of monomers

Question 11

What do the Phosphodiester bonds link?

Answer 11

The 3’OH end to the 5’OH end.

Question 12

What is the double helix in the DNA consist of and how far are the adjacent bases and how wide is it and where are the backbones and bases located on the helix?

Answer 12

• strand that runs 5’-3’ and the 3’-5’ are intertwined to form a right handed double helix

-backbones on the outside and bases on the inside

-Adjacent basses separated by 3.4 angstroms

-Approx. 20 angstrom wide

Question 13

What stabilizes the double helix?

Answer 13

-Hydrogen bonds between base pairs

-Hydrophobic interactions

-vdW forces called stacking forces between adjacent bases.

Question 14

What is a Palindrome sequence?

Answer 14

They read same forward and backward

Question 15

What do the presence of major/minor groove allow for?

Answer 15

Allows access to the hydrogen bonding capabilities of the exposed bases

Question 16

What needs to be done to the DNA in order for it to fit inside the cell?

Answer 16

DNA molecule must be compacted, the DNA double helix is a circular molecule that is twisted into a superhelix by the process of supercoiling

Question 17

What is the function of mRNA?

Answer 17

-Carries the genetic information from the nucleus to the cytoplasm , where it is translated into protein

Question 18

What is the function of tRNA?

Answer 18

Carries the Amino Acids to the mRNA for protein assembly

Question 19

What is the function of rRNA?

Answer 19

Catalytic component of the Ribosome, a machine for assembling proteins

Question 20

What is the function of IncRNA?

Answer 20

Longer RNA transcripts that regulate gene transcription ( could be a 1000 of nucleotides long)

Question 21

What is the function of microRNA?

Answer 21

About 22 base pair, double stranded RNA molecules that regulate the expression of mRNA