Nucleic Acids & Nucleotides

Question 1

DNA

Answer 1

STORE and TRANSMIT genetic information
Antiparallel double strand helix
Offset pairing of the 2 strands creates major and minor grooves

Question 2

DNA Ribose Structure

Answer 2

PENTOSE (sugar) defines whether a molecule is DNA or RNA

2’-deoxy-D-ribose (2 H groups on 2’ pentose)

Question 3

Types of RNA and Their Functions

Answer 3

mRNA- carries information from nucleus–>cytoplasm
tRNA (cytoplasm)- Translate information in mRNA; link between mRNA and AAs
rRNA (cytoplasm) - Structural component of ribosomes carries out syn of proteins

Question 4

RNA Ribose Structure

Answer 4

PENTOSE (sugar) defines whether a molecule is DNA or RNA

D-ribose (one H group and one OH group on 2’)

Question 5

Pyrimidine

Answer 5

One of the 2 nitrogenous base groups
Single Ring
Cytosine
Thymine
Uracil (RNA only) 
Pyramids CUT

Question 6

Purine

Answer 6

One of the 2 nitrogenous base groups
Double Ring
Adenine 
Guanine 
*Green Apples are Pure*

Question 7

Nucleotide

Answer 7

Must have 3 things to be an actual nucleotide

1. Nitrogenous Base (Pyrimidine or Purine)
2. Sugar (pentose)
3. Phosphate (one or more)

Question 8

RNA

Answer 8

Single Strand of Genetic Information

Can form hairpin loops (double back on itself) and bulges which gives it secondary structure

Question 9

Methylation of Bases

Answer 9

Purine and Pyrimidine bases can be methylated
(Add a CH3 group)
Methylation can help REGULATE or PROTECT genetic information

Question 10

Linkage of DNA and RNA

Answer 10

Phosphodiester linkage in a 5’–> 3’ Direction
One phosphate bonds to the 5’ of a base (below ring)
and the 3’ of a second base (above ring)

Question 11

Backbone of DNA/RNA

Answer 11

Sugar, Phosphate, Sugar 5’—>3’

Hydrophilic

Question 12

Base Pairing

Answer 12

Hydrogen bonding of a purine and a pyrimidine via amine and carbonyl groups
G=C form 3 Hydrogen bonds 
A=T form 2 Hydrogen bonds
A=U (RNA only) form 2 Hydrogen bonds
Bases are HYDROPHOBIC

Question 13

Variations of Watson and Crick Form

Answer 13

A form - Right Handed, favored in absence of water, shortest
B form - Right Handed
Z form - Left Handed looks crazy, longest

Question 14

mRNA for Polypeptide Chains

Answer 14

1. Monocistronic - codes for a single gene
2. Polycistronic - codes for more than one gene
   Both have noncoding regions (parts that mean nothing) but Polycistronic has noncoding regions between each gene segment

Question 15

Non-Enzymatic Transformations of Nucleotides and Nucleic Acids

Answer 15

1. Mutation - alters DNA structure and causes permanent changes
2. Deamination/Depurination
3. Pyrimidine dimers caused by UV
4. Reactive Chemical Interactions
5. Methylation of Bases

Question 16

Denaturing DNA

Answer 16

Heat the DNA til the H-bonds break between bases and cause the two strands to separate

Question 17

Annealing DNA

Answer 17

Cool the DNA so that it knits back together

Question 18

PCR

Answer 18

Polymerase Chain Reaction

1. Denature DNA (heat until separation at ~95*C)
2. Anneal a new primer (cool ~68*C)
3. Elongate new strand (~72*C)

Question 19

Genetic recombination experiments depend heavily upon the action of which enzymes?

Answer 19

1. DNA Ligase - facilitates the joining of DNA strands

2. Restriction Endonuclease - recognizes specific DNA sequences and cuts DNA where needed

Question 20

Which N on Purine bonds with the Pentose?

Answer 20

N in the bottom right ring (9)

Question 21

Which N on Pyrimidine bonds with the Pentose?

Answer 21

Bottom N (1)