Nucleotides, Nucleic Acids, and Heredity Flashcards
1
Q
is the transfer of characteristics, anatomical as well as biochemical, from generation to generation.
A
Heredity
2
Q
From the end of the 19th century, biologists suspected that the transmission of hereditary information took place in the ______________, more specifically in structures called ___________
A
- nucleus
- chromosomes
3
Q
The information that determines external characteristics (red hair,
blue eyes) and internal characteristics (blood group, hereditary diseases)
was thought to reside in ______ located inside the chromosomes.
A
genes
4
Q
Chemical analysis of nuclei showed chromosomes are made up largely of proteins called _______ and ______
A
- histones
- Nucleic acids
5
Q
By the 1940s, it became clear that ___________ carry the hereditary information.
A
deoxyribonucleic acids (DNA)
6
Q
Who discovered that deoxyribonucleic acid (DNA) carries the hereditary information
A
Oswald Avery
7
Q
Where are genes located?
A
DNA
8
Q
not all genes lead to the
production of protein, but all genes do lead to the production of what another type of nucleic acid?
A
ribonucleic acid (RNA)
9
Q
Other work in the 1940s demonstrated that each gene
controls the manufacture of _________
A
one protein
10
Q
Two kinds of nucleic acids are found in cells:
A
- ribonucleic acid (RNA)
- deoxyribonucleic acid (DNA)
11
Q
The expression of a gene in terms of an enzyme
protein led to the study of __________ and its control.
A
protein synthesis
12
Q
Nucleic Acid present in the chromosomes of the nuclei of eukaryotic cells
A
DNA
13
Q
Nucleic acid that is not found in the chromosomes, but rather,
is located elsewhere in the nucleus and even outside the nucleus, in the cytoplasm
A
RNA
14
Q
Both RNA and DNA are polymers built from monomers
called _________
A
nucleotides
15
Q
A nucleotide is composed of:
A
A base, a monosaccharide, and a phosphate
16
Q
The bases of found in DNA and RNA are ___________________
A
heterocyclic aromatic amines
17
Q
Two kinds of bases found in DNA and RNA
A
- Purines
- Pyrimidines
18
Q
Purine bases:
A
- adenine (A)
- guanine (G)
19
Q
Pyrimidine bases:
A
- cytosine (C)
- thymine (T)
- uracil (U)
20
Q
Base that can only be found in RNA
A
Uracil
21
Q
Base that can only be found in DNA
A
Thymine
22
Q
The sugar component of RNA
A
D-ribose
23
Q
The combination of sugar and base
A
nucleoside
23
Q
The sugar component of DNA
A
2-deoxy-D-ribose
24
A compound that consists of D-ribose or 2-deoxy-D-ribose bonded to a purine or pyrimidine base by a B-N-glycosidic bond.
Nucleoside
25
In a nucleoside, The purine bases are linked to ____ of the monosaccharide through ___
- C-1
- N-9
26
What do you call the bond that links the sugar and base in nucleosides
B-N-glycosidic bond
27
The nucleoside made of adenine and ribose
adenosine
28
In nucleosides, The pyrimidine bases are linked to ____ of the monosaccharide through
their ___
- C-1
- N-1
29
When a phosphoric acid
forms a phosphate ester bond with a nucleoside
nucleotide
30
A nucleoside in which a molecule of phosphoric acid is esterified with an -OH of the monosaccharide, most commonly either at the 3’or the 5’-OH.
Nucleotide
31
serves as a common currency into which the energy gained from food is converted and stored
adenosine 5'-triphosphate (ATP)
32
A chain of nucleotides
nucleic acid
32
Nucleic acids can be divided into two parts:
| Primary Structure
- the backbone of the molecule
- the bases that are the side-chain groups
33
Their primary structure is the _________ of nucleotides.
| Primary Structure
sequence
34
The backbone in DNA consists
of alternating ________ and _________
| Primary Structure
- deoxyribose
- phosphate groups
35
Each phosphate group is
linked to the ________ of one deoxyribose unit and simultaneously to the
_______ of the next deoxyribose unit
| Primary Structure
- 3' carbon
- 5' carbon
36
each monosaccharide unit forms a phosphate ester at the ________ and another at the _______.
| Primary Structure
- 3' position
- 5' position
37
For nucleic acids, primary structure is the sequence of
nucleotides, beginning with the nucleotide that has the ___________
| Primary Structure
free 5’ terminus
38
How do you read the primary structure of DNA strand
| Primary Structure
The strand is read from the 5’ end to the 3’ end.
39
provides structural stability for the DNA and RNA molecules.
| Primary Structure
backbone
40
, Erwin Chargaff (1905–2002) showed that:
| Primary Structure
In terms in quantity in moles:
- adenine = thymine
- guanine = cytosine
41
who established the
three-dimensional structure of DNA?
| Secondary Structure
James Watson and Francis Crick (1953)
42
Watson and Crick concluded that DNA is composed of two strands entwined around each other in a __________
| Secondary Structure
double helix
43
The ordered arrangement of nucleic
acid strands.
| Secondary Structure
Secondary structure
43
A type of 2° structure of DNA in which two polynucleotide strands are coiled around each other in a screw-like fashion.
| Secondary Structure
Double helix
44
In the DNA double helix, the two polynucleotide chains run in opposite directions (which is called _____________)
| Secondary Structure
antiparallel
45
at each end of the double helix, there is one ____ and one ____ terminus.
| Secondary Structure
- 5'-OH
- 3'-OH
46
The sugar–phosphate backbone is on the _______, exposed to the aqueous environment, and the bases point ______-.
| Secondary Structure
- outside
- inward
47
The bases are ________, so they try to avoid contact with water
| Secondary Structure
hydrophobic
48
For each adenine on one chain, a thymine is aligned opposite it on the other chain;each guanine on one chain has a cytosine aligned with it on the other chain
| Secondary Structure
Chargaff’s rule
49
A-T and G-C are called?
| Secondary Structure
complementary base pairs.
50
The bases are paired according to ___________
Chargaff’s rule
51
A and T pair by forming
____________. G and C
pair by forming _________.
| Secondary Structure
- two hydrogen bonds
- three hydrogen bonds
52
It is the most common and most stable form of DNA
| Secondary Structure
B-DNA
53
With B-DNA, a distinguishing feature is the presence of a _________ and a ________, which arise because the two strands are not equally spaced around the helix
| Secondary Structure
- major groove
- minor groove
54
If a human DNA molecule were fully stretched out, its length would be perhaps ___
| Higher-Order Structures of DNA
1 meter
55
the DNA molecules in the nuclei are not stretched out, but rather, coiled around basic protein molecules called?
| Higher-Order Structures of DNA
histones
56
The histones comprise five main types:
| Higher-Order Structures of DNA
H1, H2A, H2B, H3, and H4
57
# Higher-Order Structures of DNA
Histones contain large numbers of basic amino acid residues, such as _______ and ________.
- lysine
- arginine
58
The negatively-charged DNA molecules and positively-charged histones attract one another and form units called?
| Higher-Order Structures of DNA
nucleosomes
59
The acidic DNA and the basic histones attract each other by
__________, combining to form units called nucleosomes.
| Higher-Order Structures of DNA
electrostatic (ionic) forces
60
In a nucleosome, ________ form a core, around which a 147-base-pair DNA double helix is wound.
| Higher-Order Structures of DNA
eight histone molecules
61
Nucleosomes are further condensed into ________
| Higher-Order Structures of DNA
chromatin
62
Nucleosomes are further condensed into chromatin where a 30-nm-wide fiber forms in which nucleosomes are wound in a ____________ fashion
| Higher-Order Structures of DNA
solenoid
63
Solenoids have ___________ per turn
| Higher-Order Structures of DNA
six nucleosomes
64
Chromatin fibers are organized into loops, and the
loops into the bands that provide the superstructure of __________.
| Higher-Order Structures of DNA
chromosomes
65
Superstructures of chromosomes:
| Higher-Order Structures of DNA
1. DNA double helix
2. Nucleosome
3. "Beads on a string" chromatin form
4. Solenoid (six nucleosomes per turn)
5. Loops (50 turns per loop)
6. Miniband (18 loops)
7. Chromosome (stacked minibands)
66
Transports amino acids to site of protein
synthesis
| Types of RNA
Transfer RNA (tRNA)
67
Combines with proteins to form ribosomes, the site of protein synthesis
| Types of RNA
Ribosomal RNA
(rRNA)
68
Directs amino sequence of proteins.
| Types of RNA
Messenger RNA
(mRNA)
69
Processes intitial mRNA to its mature form in eukaryotes.
| Types of RNA
Small nuclear RNA
(snRNA)
70
Affects gene expression; important in growth and development
| Types of RNA
Micro RNA (miRNA)
70
Affects gene expression; used by scientists to knock out a gene being studied
| Types of RNA
Small interfering
RNA (siRNA)
71
Types of RNA that are small in terms of size:
| Types of RNA
- Transfer RNA (tRNA)
- Small nuclear RNA (snRNA)
- Micro RNA (miRNA)
- Small interfering RNA (siRNA)
- Piwi-associated RNA (piRNA)
72
Types of RNA that are variable in terms of size:
| Types of RNA
- Ribosomal RNA (rRNA)
- Messenger RNA (mRNA)
- Long non-coding RNA (lncRNA)
- Circular RNA
72
mRNA molecules are produced in the process called _________
| Types of RNA
transcription
73
mRNA molecules carry the __________ from the DNA in the nucleus directly to the cytoplasm, where most of the protein is synthesized.
| Types of RNA
genetic information
74
Messenger RNA consists of a chain of nucleotides whose sequence is exactly ____________ to that of one of the strands of the DNA.
| Types of RNA
complementary
75
The size of mRNA varies widely, with the average unit
containing perhaps _____ nucleotides.
| Types of RNA
750
76
Containing from ________ nucleotides per chain, tRNAs are relatively small molecules
| Types of RNA
73 to 93
77
The three-dimensional tRNA molecules are ___________, but they are conventionally represented as a cloverleaf in two dimensions.
| Types of RNA
L-shaped
77
Process where the sequence of bases in DNA is recorded as a sequence of complementary bases in a singlestranded mRNA molecule.
| Types of RNA
Transcription
78
Three-base codons on the mRNA
corresponding to specific amino acids direct the sequence of building a protein. These codons are recognized by tRNAs (transfer RNAs) carrying the
appropriate amino acids. Ribosomes are the “machinery” for protein synthesis.
| Types of RNA
Translation
79
What are ribosomes consist of?
| Types of RNA
35% protein and 65% ribosomal RNA
80
Where does protein synthesis take place?
| Types of RNA
Ribosomes
81
Small Nuclear RNA (snRNA) is complexed with proteins to form what?
| Types of RNA
small nuclear ribonucleoprotein particles, snRNPs
82
Their function is splicing
| Types of RNA
small nuclear ribonucleoprotein particles, snRNPs
83
Processing of the initial mRNA transcribed from DNA into a mature form that is ready for export out of the nucleus.
| Types of RNA
splicing
84
They play important roles in cancer, stress responses, and viral infections
| Types of RNA
Micro RNA (miRNA)
85
They inhibit translation of mRNA into protein and promote the degradation of mRNA.
| Types of RNA
Micro RNA (miRNA)
86
Short stretches of RNA (20–30 nucleotides long), called ____________, have been found to have an enormous control over
gene expression.
| Types of RNA
Small Interfering RNA (siRNA)
86
degrade specific mRNA molecules to control gene activity
| Types of RNA
Small Interfering RNA (siRNA)
87
Involved in activating or silencing specific genes
| Types of RNA
Long non-coding RNA (lncRNA)
87
Protect animal genomes against transposons
| Types of RNA
Piwi-associated RNA (piRNA)
87
Acts as miRNA sponge, controlling the effects of miRNA
| Types of RNA
Circular RNA
87
a stretch of DNA, containing a few hundred nucleotides, that carries one particular message
Genes
87
A segment of DNA that carries a base sequence that directs the synthesis of a particular protein, tRNA, or mRNA.
Genes
88
In bacteria, the gene is _________
| Genes
continuous
89
In higher organisms, the gene is ________
| Genes
discontinuous
89
A section of DNA that, when transcribed, codes for a protein or RNA.
| Genes
Exon
90
A section of DNA that does not code for anything functional.
| Genes
Intron
91
exons, short for
| Genes
“expressed sequences”
91
introns, short for
| Genes
“intervening sequences”
92
are DNA molecules in which short nucleotide sequences are repeated hundreds or thousands of times.
| Genes
Satellites
93
Smaller repetitive sequences, called _____________, are associated with cancer when they mutate.
mini-satellites or microsatellites
94
Adenine (A)
| Nucleotides in DNA
Deoxyadenosine 5'-monophosphate (dAMP)
95
Guanine
| Nucleotides in DNA
Deoxyguanosine 5'-monophosphate (dGMP)
96
Thymine
| Nucleotides in DNA
Deoxythymidine 5'-monophosphate (dTMP)
97
Cytosine
| Nucleotides in DNA
Deoxycytidine 5'-monophosphate (dCMP)
98
Adenine
| Nucleotides in RNA
Adenosine 5'-monophosphate (AMP)
99
Guanine
| Nucleotides in RNA
Guanosine 5'-monophosphate (GMP)
100
Uracil
| Nucleotides in RNA
Uridine 5'-monophosphate (UMP)
101
Cytosine
| Nucleotides in RNA
Cytidine 5'-monophosphate (CMP)
102
A complete polarity (antiparallel)
turn of the helix spans _____ base pairs
| Secondary Structure
ten
103
A complete polarity (antiparallel)
turn of the helix covers a distance of _________
| Secondary Structure
34 Å (3.4 nm)
104
The individual
base pairs are spaced __________ apart.
| Secondary Structure
3.4 Å (0.34 nm)
104
The
inside diameter of a double helix
| Secondary Structure
11 Å (1.1 nm)
105
the outside
diameter of a double helix
| Secondary Structure
20 Å (2.0 nm)
106
a form of a DNA double helix
characterized by having fewer residues per turn and major and minor grooves with dimensions that are more similar to each
other than those of B-DNA
| Secondary Structure
A-DNA
107
a form of DNA that is a left-handed helix, which has been seen to occur naturally under certain circumstances
| Secondary Structure
Z-DNA
108
interactions between bases that are next to each other in a DNA chain
| Secondary Structure
base stacking
108
extra twists (over and above
those of the double helix) in closed circular
DNA
| Secondary Structure
supercoils
109
circular DNA with
fewer than the normal number of turns of
the helix
| Secondary Structure
negative supercoils
110
circular DNA with more
than the normal number of turns of the
helix
| Secondary Structure
positive supercoils
111
enzymes that relax
supercoiling in closed circular DNA
| Secondary Structure
topoisomerases
112
cut the phosphodiester backbone of one strand of DNA, pass the other end through, and then reseal the backbone.
| Secondary Structure
Class I
topoisomerases
113
# Secondary Structure
cut both strands of DNA, pass some of the remaining DNA helix between the cut ends, and then reseal.
Class II topoisomerases
114
an enzyme that introduces supercoiling into closed circular DNA
| Secondary Structure
DNA gyrase
115
What class of topoisomerase is DNA gyrase
| Secondary Structure
class II topoisomerase
115
a complex of DNA and protein found in eukaryotic nuclei
| chromatin
chromatin
116
basic proteins found complexed to
eukaryotic DNA
histones
117
a globular structure in
chromatin in which DNA is wrapped around an aggregate of histone molecules
nucleosome
