Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

biochem > NUCLEOTIDES > Flashcards

NUCLEOTIDES Flashcards

1
Q

______ are long chains of repeated nucleotides

A

Nucleic acids (DNA and RNA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Nucleic acids are formed by the combination of nucleotide molecules through

A

sugar-phosphate

bonds known as phosphodiester linkages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

A nucleotide consists of:

A

o Nitrogenous base
o Pentose sugar
o One or more phosphate groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q 
They are monomeric units of nucleic acids and also serve as sources of chemical energy (ATP,
GTP), participate in cellular signalling (cAMP, cGMP) and function as important cofactors of
enzymatic reactions (coA, FAD, FMN, NAD+)
A

NUCLEOTIDES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The molecule without the phosphate group of nucleotides is called as ____.

A

nucleoside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

___ are glycosylamines consisting simply of a nitrogenous base and a five-carbon sugar (either ribose or deoxyribose)

A

Nucleosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

With all three joined, a nucleotide is also termed a

A

“nucleoside phosphate”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The nitrogenous base is either a

A

purine or a pyrimidine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

There are ___ major bases found in cells.

A

five

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The derivatives of purine are called

A

adenine and guanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

derivatives of pyrimidine are called

A

thymine, cytosine and uracil.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Purines include adenine and guanine and have

A

two rings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Adenine has an _____ group on its rings, whereas guanine has a ___ group.

A

ammonia

ketone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Pyrimidines include cytosine, thiamine, and uracil and have ____.

A

one ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Thymine (found in DNA) and uracil (found in RNA) are

A

similar in that they both have

ketone groups, but thymine has an extra methyl group on its ring.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Bonds between guanine and cytosine (three hydrogen bonds) are stronger than

A

bonds between adenine and thymine (two hydrogen bonds).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The five-carbon sugar is either a

A

ribose (in RNA) or a deoxyribose (in DNA) molecule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In nucleotides, both types of pentose sugars are in their

A

beta-furanose (closed five- membered ring) form.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

PROPERTIES OF NUCLEOTIDES

A 
 Sparingly soluble in water
 Absorb light in UV region at 260 nm. 
 Capable of forming hydrogen bond
 Aromatic base atoms numbered 1 to 9
 Purine ring is formed by fusion of pyrimidine ring with imidazole ring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

STRUCTURE OF NUCLEOSIDES

A

In a nucleoside, the base is bound to either ribose or deoxyribose via a beta-glycosidic linkage at 1’ position.

Examples of nucleosides include cytidine, uridine, adenosine, guanosine, thymidine and inosine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

PROPERTIES OF PYRIMIDINE BASES

A

 Soluble at body pH
 Also absorb UV light at 260 nm
 Capable of forming hydrogen bond
 Aromatic base atoms are numbered 1 to 6 for pyrimidine.
 Atoms or group attached to base atoms have same number as the ring atom to which they are bonded.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

PROPERTIES OF PENTOSE SUGARS

A

 A pentose is a monosaccharide with five carbon atoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

is the most common pentose with one oxygen atom attached to each carbon atom.

A

Ribose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Deoxyribose sugar is derived from the

A

sugar ribose by loss of an oxygen atom.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The aldehyde functional group in the carbohydrates react with neighbouring hydroxyl functional groups to form

A

intramolecular hemiacetals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The resulting ring structure is related to furan, and is termed a

A

furanose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The ring spontaneously opens and closes, allowing rotation to occur about the bond between the carbonyl group and the neighboring carbon atom yielding two distinct configurations (α and
β). This process is termed

A

mutarotation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

___ if the sugar is ribose.

A

Ribonucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

if the sugar is deoxyribose.

A

Deoxyribonucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q 
Located in
the nucleus
of the cell
and self-
replicating
A

DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Storage
form of
genetic
information

A

DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Base
pairing is AT
and GC

A

DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q 
Copied from
DNA and is
working form
of the
information
A

RNA

34
Q 
Made in the
nucleus and
mRNA is
exported to
the cytosol
A

RNA

35
Q

Base pairing is

AU and GC

A

RNA

36
Q

Adenosine nucleotides:

A

ATP, ADP, AMP, Cyclic AMP

37
Q

Guanosine nucleotides:

A

GTP, GDP, GMP, Cyclic GMP

38
Q

Cytidine nucleotides:

A

CTP, CDP, CMP and certain deoxy CDP derivatives of glucose, choline
and ethanolamine

39
Q

Uridine nucleotides:

A

UDP

40
Q

Miscellaneous :

A

PAPS (active sulphate), SAM (active methionine), certain coenzymes like
NAD+, FAD, FMN, Cobamide coenzyme, CoA

41
Q

The ____are of great importance to living organisms, as they are the building blocks of nucleic acids, the substances that control all hereditary characteristics.

A

nucleotides

42
Q

consist of nucleosides joined by 3′,5′-phosphodiester bridges. The genetic message resides in the sequence of bases along the polynucleotide chain.

A

Polynucleotides

43
Q

have a variety of roles in cellular metabolism. They are the energy currency in metabolic transactions.

A

Nucleotides

44
Q

They act as essential chemical links in the response of cells to hormones and other
extracellular stimuli.

A

NUCLEOTIDES

45
Q

They are the structural components of an array of enzyme cofactors and metabolic
intermediates.

A

NUCLEOTIDES

46
Q

The structure of every protein, and ultimately of every biomolecule and cellular component, is a product of information programmed into the

A

nucleotide sequence of a cell’s nucleic acids.

47
Q

Serving as energy stores for future use in phosphate transfer reactions. These reactions are predominantly carried out

A

ATP.

48
Q

A cell’s hereditary information is encoded in in the cell’s nucleus.

A

chromosomes

49
Q

Each chromosome is composed of

A

proteins and deoxyribonucleic acid (DNA).

50
Q

The chromosomes contain smaller hereditary units called ___, which are relatively short segments of DNA.

A

genes

51
Q

The hereditary information is expressed or used through the synthesis of

A

ribonucleic acid (RNA).

52
Q

Both nucleic acids—DNA and RNA—are polymers composed of monomers known
as ___, which in turn consist of phosphoric acid (H3PO4), a nitrogenous base, and a pentose sugar.

A

nucleotides

53
Q

RNA is a single-chain nucleic acid, whereas DNA possesses two nucleic-acid chains intertwined in a secondary structure called a

A

double helix.

54
Q

Hydrogen bonding between ___ holds the two strands of the double helix
together; A always pairs with T and C always pairs with G.

A

complementary bases

55
Q

Cell growth requires ____ of the cell’s DNA.

A

replication, or reproduction

56
Q

For protein synthesis, three types of RNA are needed: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). All are made from a DNA template by a process called

A

transcription

57
Q

is the process in which proteins are synthesized from the information in mRNA.

A

Translation

58
Q

It occurs at structures called ___, which are located outside the nucleus and are composed of rRNA and protein.

A

ribosomes

59
Q

The ____ possible three-nucleotide combinations of the 4 nucleotides of DNA constitute the ____ that dictates the sequence in which amino acids are joined to make proteins.

A

64

genetic code

60
Q

Each three-nucleotide sequence on mRNA is a ___.

A

codon

61
Q

Each kind of tRNA molecule binds a specific amino acid and has a site containing a three- nucleotide sequence called an anticodon.

A

ANTICODON

62
Q

The general term for any change in the genetic code in an organism’s DNA is ___.

A

mutation

63
Q

A change in which a single base is substituted, inserted, or deleted is a

A

point mutation

64
Q

The chemical and/or physical agents that cause mutations are called

A

mutagens

65
Q

Diseases that occur due to mutations in critical DNA sequences are referred to as

A

genetic diseases

66
Q

The 5’terminus of mRNA is “capped” with a

A

methylated base of Guanosine 5’ triphosphate.

67
Q

The length of tRNAs ranges from

A

65-110 nucleotides with a corresponding molecular weight of 22, 000-37500 Daltons.

68
Q

The __ is a single stranded.

A

tRNA

69
Q

___ are found associated with large number of proteins in an ordered complex.

A

Ribosomal RNA

70
Q

has a helical structure resulting from the folding back of single stranded polymer and constitute about 74-80% of total RNA in a cell.

A

Ribosomal RNA

71
Q

are synthesized in cytoplasm of most of the tissues.

A

Purine nucleotides

72
Q

The major site for purine

synthesis is

A

liver

73
Q

Since purine ring are synthesized from different small components, they are makorly denoted by

A

de novo synthesis

74
Q

(PRPP)

A

Phospho ribosyl phyrophosphate

75
Q

(APRTase)

A

Adenine phosphor ribosyl transferase

76
Q

(HGPRTase)

A

Hypoxanthine guanine phosphoribosyl transferase

77
Q

The most common abnormality of purine metabolism is

A

elevation of uric acid level in blood.

78
Q

Elevated level of uric acid in blood is called as

A

hyper-uricemia

79
Q

In hyperuricemia the serum uric acid level

exceeds the level of

A

7 mg/dl for male and 6 mg/dl in female.

80
Q

This increased uric acid may or may not be

excreated via urine and the condition is called as

A

uricosuria

biochem (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions