Nucleic Acid Structure and Function

Question 1

What is the central dogma of molecular biology?

Answer 1

Flow of information from DNA to RNA to protein

Descriptive of all organisms, exception of some viruses that have RNA as the repository of their genetic information

Question 2

This rule explains why in any samply of dsDNA, the amount of adenine equals the amount of thymine..guanine = cytosine, purine = pyramidine

Answer 2

Chargaff Rule

Question 3

Base pairs are held together by _______ bonds

How many are between A and T? G and C?

Hint: This type of bond stabilize the structure of double helix

Answer 3

Hydrogen bonds

A and T = 2
C and G = 3

Question 4

Loss of helical structure in DNA

Can be monitored by measuring its absorbance at 260 nm

Answer 4

Denaturation

Question 5

TRUE or FALSE

DNA that contains high concentrations of A and T denatures at a HIGHER temperature than G- and C-rich DNA

Answer 5

FALSE

LOWER temperature

Question 6

Small, circular, extrachromosomal DNA molecules found in most species of bacteria that may carry genes that convey antibiotic resistance to the host bacterium

Answer 6

Plasmids

Question 7

What are the DNA and RNA purines?

Answer 7

Adenine (A)

Guanine (G)

Question 8

What are the RNA pyrimidines?

Answer 8

Cytosine (C) and Uracil (U)

Question 9

What are the DNA pyrimidines?

Answer 9

Cytosine (C) and Thymine (T)

DNA - Thymine has a methyl group
RNA - Uracil

Question 10

What compose nucleotides?

Hint: 3

Answer 10

1. Nitrogenous base
2. Pentose monosaccharide
3. 1-3 phosphate groups

Question 11

Pentose sugar + Base

Answer 11

Nucleoside

Ribonucleoside of:
A - adenosine
G - guanosine
C - cytidine
U - uridine

Deoxyribonucleoside (just add the prefix ‘deoxy-‘)

Question 12

Addition of one or more phosphate groups to a nucleoside produces?

Answer 12

Nucleotide

Question 13

TRUE or FALSE

The phosphate groups are responsible for the negative charges associated with nucleotides

Answer 13

True

Question 14

TRUE or FALSE

Adenosine triphosphate is a nucleotide

Answer 14

True

Nucleotide = Ribose + base + phosphate group(s)

Question 15

Purine or pyrimidine?

Constructed primarily in the liver
Series of reactions that add the donated carbons and nitrogens to a preformed ribose 5-phosphate

Answer 15

Purine ring

Question 16

This ‘activated pentose’ participates in the synthesis and salvage of purines and pyrimidines.

Hint: Synthesized first in purine nucleotides

Answer 16

PRPP

5-phosphoribosyl-1-pyprophosphate

Its sugar moiety is ribose.