Chapter 8: Nucleotides and Nucleic Acids

Question 1

What is a “Nucleotide”

Answer 1

Nitrogeneous base
Pentose
Phosphate

Question 2

What is a “Nucleoside”

Answer 2

Nitrogeneous base

Pentose

Question 3

What is a “Base”

Answer 3

Nitrogeneous base

Question 4

What are 7 functions of Nucleotides?

Answer 4

Energy for metabolism (ATP)
– Enzyme cofactors (NAD+)
– Signal transduction (cAMP)
– Storage of genetic info (DNA)
– Transmission of genetic info (mRNA)
– Catalysis (ribozymes)
– Protein synthesis (tRNA and rRNA)

Question 5

At what pH is a Phosphate group charged?

Answer 5

Negatively charged at neutral pH

Question 6

Where is the phosphate group typically attached?

Answer 6

At the 5’ position (but may also be attached to other positions)

Question 7

What’s the difference between a ribonucleoside and a dexoyribonucleoside? What are there abbreviations?

Answer 7

ribonucleoside (ex: AMP, ADP, ATP) has a 2’OH group and dexoyribonucleoside (dAMP, dADP, dATP) has a 2’ H group.

Question 8

Derivatives of pyrimidine or purine
Nitrogen-containing heteroaromatic
molecules
Planar or almost planar structures
Absorb UV light around 250-270 nm

Answer 8

Nucleobases

Question 9

In pyrimidine bases, where are both DNA and RNA found?

Answer 9

Cytosine

Question 10

In pyrimidine bases, where are DNA only found?

Answer 10

Thymine

Question 11

In pyrimidine bases, where are RNA only found?

Answer 11

Uracil

Question 12

Pyrimidine Bases (Cytosine, Thymine, Uracil) are neutral molecules at pH 7 and are good what?

Answer 12

H-bond donors and acceptors

Question 13

In purine bases, where are Adenine and Guanine found?

Answer 13

both DNA and RNA

Question 14

Good H-bond donors and acceptors

Neutral molecules at pH 7

Answer 14

Purine Bases

Question 15

In nucleosides and nucleotides, the pentose ring is attached to the base via an ___ and formed how?

Answer 15

N-glycosidic bond. Bond is formed to the anomeric carbon of the sugar in Beta-configuration

Question 16

Beta N-glycosidic bond is formed to what position in pyrimidines?
in purines

Answer 16

N1

Question 17

Beta N-glycosidic bond is formed to what position in purines?

Answer 17

N9

Question 18

Is Deoxyadenylate (deoxyadenosine 5’-monophosphate) a nucleotide or nucleoside nomenclature?

Answer 18

nucleotide

Question 19

Is Deoxyadenosine a nucleotide or nucleoside nomenclature?

Answer 19

nucleoside

Question 20

What are the SYMBOLS for “Deoxyadenylate” (deoxyadenosine 5’-monophosphate) and “Deoxyguanylate” (deoxyguanosine 5’-monophosphate)?

Answer 20

A, dA, dAMP; G, dG, dGMP

Question 21

What kind of rotation can occur around the N-glycosidic

bond in free nucleotides?

Answer 21

free

Question 22

What conformations occur in N-Glycosidic Bond?

Answer 22

syn or anti

Question 23

What’s the nucleic acid for Purine?

Answer 23

None

Question 24

What’s the nucleic acid for Adenine?

Answer 24

RNA and DNA

Question 25

What's the nucleic acid for Guanine?

Answer 25

RNA and DNA

Question 26

What's the nucleic acid for Pyrimidines?

Answer 26

None

Question 27

What's the nucleic acid for Cytosine?

Answer 27

RNA and DNA

Question 28

What's the nucleic acid for Thymine?

Answer 28

DNA

Question 29

What's the nucleic acid for Uracil?

Answer 29

RNA

Question 30

Is Adenylate a nucleotide or nucleoside nomenclature?

Answer 30

Nucleotide

Question 31

What are the SYMBOLS for "Adenylate" (adenosine 5'-monophosphate)

Answer 31

A, AMP

Question 32

TRUE/FALSE: | Modification of nucleotides is done after DNA synthesis

Answer 32

True

Question 33

Where is 5-Methyldeoxycytidylate commonly found?

Answer 33

Eukaryotes (also found in bacteria)

Question 34

Where is N6-Methyldeoxyadenylate commonly found?

Answer 34

Bacteria (not found in bacteria)

Question 35

In prokaryotes, what is the epigenetic marker?

Answer 35

Mark own DNA so that cells can degrade foreign DNA

Question 36

In eukaryotes, what is the epigenetic marker?

Answer 36

Mark which genes should be active (negative | regulation)

Question 37

What are some minor nucleotides in RNA?

Answer 37

Inosine and Pseudouridine

Question 38

Where is Inosine found?

Answer 38

in the “wobble position” of the anticodon in | tRNA

Question 39

Where is Pseudouridine found?

Answer 39

widely in tRNA and rRNA

Question 40

How is Inosine made?

Answer 40

deaminating adenosine

Question 41

How does pseudouridine assist tRNA?

Answer 41

stabilize the structure of tRNA

Question 42

How does pseudouridine assist rRNA?

Answer 42

folding of rRNA

Question 43

DNA backbone is fairly stable or unstable?

Answer 43

fairly stable

Question 44

RNA backbone is fairly stable or unstable?

Answer 44

unstable

Question 45

We read polynucleotides in what direction?

Answer 45

read the sequence from 5’ to 3’

Question 46

Polynucleotides have linear polymers which means?

Answer 46

no branching or cross-links

Question 47

TRUE/FALSE: | Polynucleotides, with a negatively charged backbone, are covalent bonds formed via phosphodiester linkages

Answer 47

True

Question 48

Hydrolysis of DNA is catalyzed by what enzyme?

Answer 48

DNAse

Question 49

Hydrolysis of RNA is catalyzed by what enzyme?

Answer 49

RNAse

Question 50

Watson-Crick base pairs predominate in double-stranded | DNA. What are the pairs for A, T, C, G, Purine, Pyrimidine?

Answer 50

A pairs with T C pairs with G Purine pairs with pyrimidine

Question 51

In Hydrogen bonding interactions,

Answer 51

Two bases can hydrogen bond to form a base pair

Question 52

TRUE/FALSE: For monomers, large number of base pairs is possible. In polynucleotide, only few possibilities exist

Answer 52

True

Question 53

What are required for complementarity of DNA?

Answer 53

Two chains differ in sequence(read from 5’ to 3’) Two chains are complementary Two chains run antiparallel

Question 54

TRUE/FALSE: A-T and C-G pairs are favorable?

Answer 54

True

Question 55

First, strand separation. Each strand serves as a template for the synthesis of a new strand. Synthesis is catalyzed by enzymes known as DNA polymerases. Newly made DNA molecule has one daughter strand and one parent strand.

Answer 55

Replication flow of Genetic Code

Question 56

Code Carrier for the Sequence of Proteins

Answer 56

Messenger RNA (mRNA)

Question 57

Instead of deoxyribose and thymine, mRNA contains what?

Answer 57

Contains ribose and uracil

Question 58

mRNA is single or double stranded?

Answer 58

Single

Question 59

TRUE/FALSE: mRNA is synthesized using DNA template?

Answer 59

True

Question 60

One mRNA may code for how many proteins?

Answer 60

more than one protein (polycistronic)

Question 61

Matching Amino Acids with the mRNA Code

Answer 61

Transfer RNA (tRNA)

Question 62

TRUE/FALSE: tRNA molecules have quite complex structures, this is an actively studied field

Answer 62

True