Section 2 - Module 6 Flashcards

1
Q

What is the significance of 1952?

A

Year that Alfred Hershey and Martha Chase demonstrated that DNA and not proteins is transmitted on to progeny. DNA as the genetics material in Bacteriophages

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

Frederick Griffin’s work

A

Demonstrated cell can be transformed

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

What is the transforming principle?

A

DNA

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

What is Transformation?

A

acquiring new genetic material from uptake of external source

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

What bacteria did Hersey work with?

A

E/coli and their associated bacteriophage

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

Aaron Levene’s work?

A

Proposed tetranucleotide theory. Stating that DNA is made of repeating units called nucleotides

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

Albrecht Kossel’s work?

A

Determined nucleic acids contain four nitrogenous bases.

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

The four nitrogenous bases in DNA

A

Adenine (A), Cytosine (C), Guanine (G), Thymine (T)

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

The four nitrogenous bases of RNA

A

Adenine (A), Cytosine (C), Guanine (G), Uracil (U)

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

Significance of 1953?

A

Year Franklin and Wilkins devise the secondary structure of DNA. The double helix structure of DNA

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

DNA secondary structure

A

Structure of the set interactions between bases. Such as which parts of the strands are bound to each other and phosphate backbone.

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

Significance of 1948?

A

Year Erwin Chargaff discovered pattern in DNA base pairs. Nucleotide compositions DNA - A=T; G=C.

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

Describe nucleotide structure

A

Phosphate group, base (A, G, G, t), and deoxyribose sugar. Purines attached to pyridines

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

Purines

A

Adenine (A) and Guanine (G). They has an additional ring structure

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

Pyridines

A

Cytosine (C) and Thymine (T). They have an amide functional group

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

Phosphate group is attached to the __ carbon of deoxyribose sugar

A

5’

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

Base is attached to the _ carbon in deoxyribose

A

1’

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

What makes up deoxyribose sugars of DNA?

A

5 carbons with OH at 3’ carbon. Between 4’ and 1’ there is an ether (O).

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

What is different in RNA structure?

A

it is a ribose sugar and has an additional OH on carbon 2’. uses the U base T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Nucleoside

A

Sugar + Base (exposed nitrogenous bases)

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

Nucleotide

A

Sugar + Base + Phosphate group

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

Chargaff’s Rule

A

Purine(A+G)/Pyrimidines (T+C) = 1.0 approximately

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

Double stranded DNA

A

(C+T) = (A+G)

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

Rosalind Franklin and Maurice Wilkins

A

x-ray diffraction lead to discovery of DNA being a helix of constant diameter

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

Erwin Chargraff

A

Base pairing

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

Direction DNA spiraling around helix axis

A

anti-parallel (opposite directions)

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

Direction of reading DNA

A

5’ to 3’

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

What is perpendicular to the helix axis in DNA?

A

Base pairs

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

DNA two Grooves

A

Major and minor grooves allow for proteins to bind to and recognize DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Another way to refer to denaturing of DNA

A

Melting

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

What is “Melting”

A

Separation of two DNA strands, to single stranded DNA (ssDNA)

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

What is reversible posses in separation of DNA

A

Renaturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Ways to denature or “melt” DNA

A

Increase temperature, reduce salt concentration, increase pH, solvents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Melting Temperature (Tm) of DNA

A

Defined as the temperature when DNA duplex is separated into single strands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What can DNA Tm indicate

A

duplex (hybridized DNA molecules) stability, higher Tm the more stable the DNA helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How to measure DNA denaturation

A

absorbance. AS DNA duplex separated, the absorbance increases (hyperchromic shift).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What does higher Tm indicate?

A

More stable DNA helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How does GC content (% G+C), effect melting temperature?

A

Higher GC content increases stability, therefore increasing melting temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

How does salt concentration effect melting temperature?

A

Higher salt concentration, higher the melting temperature. Salt causes the phosphate backbone to the tightly packed, and this shield the negative charged of the phosphate backbone. Increases stability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

How can GC content in DNA classify organisms?

A

It is species specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Does mutated of normal DNA have higher melting point?

A

Mutated melting rages are just different than “normal” ranges no specification of higher or lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Molecular Biology Techniques involving DNA melting

A

polymerase chain reaction (PCR) and southern blotting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Equation for Melting Temperature

A

Tm = 81.5 + 16.6 lg [M] + 0.41(%GC) - 675/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The three proposed models of DNA replication

A

Conservative, dispersive, and semiconservative replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Correct model of DNA replication

A

semiconservative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What results of 1st round of Meselson experiment?

A

50% light and 50% heavy so NOT conservative replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is results of 2ndround of Meselson experiment?

A

There where some DNA that were 100% intermediate. So NOT intermediate replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Semi-conservative replication

A

Each daughter cell consists of one parental strand and one newly synthesized strands based off a parental strand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

DNA synthesis Requirements

A

1) ssDNA template
2) all four dNTPs
3) DNA polymerase and other supporting enzymes
4) Free 3’-OH group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

dNTPS

A

deoxynucleotide triphosphate, with each using a different DNA base: adenine (dATP), cytosine (dCTP), guanine (dGTP), and thymine (dTTP).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Mechanism of DNA Synthesis

A

Catalysis of phosphodiester bond between dNTPS and bases

52
Q

Direction of DNA chain elongation

A

5’ to 3;

53
Q

Template strand reading direction

A

3’ to 5’

54
Q

Origin of Replication

A

the specific nucleotide sequence where replication begins

55
Q

Where dies synthesis take place

A

Within a replication bubble

56
Q

Where are DNA strands synthesized simultaneously

A

replication fork

57
Q

What is a DNA molecule/region of DNA that replicates from a single origin of replication called?

A

Replicon

58
Q

Replication is ______

A

Semicontinuous

59
Q

Leading strand synthesis is _ and the direction of the fork

A

continuous

60
Q

Lagging strand synthesis is _ and occurs in the opposite direction of the fork

A

discontinuous

61
Q

Bacteria Genome

A

Circular

62
Q

Bacteria Replication

A

Theta replication

63
Q

Virus Genome

A

Circular

64
Q

Virus Replication

A

Rolling circle replication

65
Q

Eukaryotes Genome

A

Linear

66
Q

Eukaryotic replication

A

Linear replication

67
Q

Theta replication

A

1) single replicon (entire chromosome)
2) bidirectional replication w two forks within a single bubble
3) semi discontinuous in both replications forks
4) results in two circular DNA molecules

68
Q

Rolling circle

A

1) no replication bubble
2) uncoupling of the replication of the two DNA molecules
3) replication is continuous
4) results in multiple circular DNA molecules

69
Q

Linear

A

1) multiple replicons, origins or replication, and replication bubbles
2) bidirectional
3) Semi discontinuous at both replication forks
4) results in two linear DNA molecules

70
Q

Four stages of replication

A

1) Initiation
2) unwinding
3) elongation
4) termination

71
Q

Initiation

A

Initiator protein bind to the origin of replication (oriC) and a short section of DNA unwinds and proteins bein the ssDNA. ss-binding-protein keeps DNA separated and Helicases binds to the lagging strand template and breaks hydrogen bonds.

72
Q

What bonds to helicases break

A

hydrogen bonds

73
Q

Unwinding

A

Helicases break the hydrogen bonds between DNA strands while DNA gyrase (a topoisomerase) travels ahead of the fork and alleviates supercoiling caused by unwinding

74
Q

What does unwinding cause without DNA gyrase to reverse

A

supercoiling

75
Q

Chain Elongation

A

RNA primer (RNA nucleotides stretch) is synthesized by Primase. RNA primer provides a free 3’ OH for the DNA polymerases to use. RNA primer is replaced with nucleotides

76
Q

Why do we require an RNA primer?

A

Because the production of RNA does NOT require a 3’ end

77
Q

E. Coli principle replication enzyme

A

Pol III

77
Q

DNA ligase

A

seals the nick in the sugar phosphate backbone

77
Q

What DNA polymerase activity fills in the gap of DNA nucleotides (E. Coli)

A

Pol I

77
Q

Exonucleases

A

Removes primers starting at the 5’ ends. Removes Newley incorporated nucletides that do not match the template strand

77
Q

E. Coli polymerase that removes and replication RNA primers with DNA

A

pol I

78
Q

How many E. Coli DNA polymerases are there

A

Five (Pol I to Pol V)

79
Q

Eukaryotic DNA polymerases

A

Alpha, delta, and epsilon (all 5’ to 3’ activity) (delta and epsilon do 3’ to 3’ exonuclease activity)

80
Q

Delta DNA polymerase

A

Lagging-strand synthesis of nuclear DNA, DNA repair, and translesion DNA synthesis

80
Q

Alpha DNA polymerase

A

Initiation of nuclear DNA synthesis and DNA repair; has primase activity

80
Q

Epsilon DNA polymerase

A

Leading-strand synthesis

80
Q

Benefit of more origins in human DNA synthesis?

A

multiple origins ensure efficient genome replication in limited time

80
Q

Eukaryotic DNA is packaged into ____

A

Chromatin

80
Q

Telomeres

A

1) are the end of linear chromosomes
2) made up of G-rich short repeated sequences
3) stabilize chromosomes
specialized reverse transcriptase
4) extends the end of the parental DNA by RNA-templated DNA synthesis
5) responsible for the replication of the chromosomes ends
6) extends the DNA, filling int he gap due to the removal of the RNA primer

81
Q

Transcription + translation =

A

gene expression

82
Q

DNA replication

A

information transferred from one DNA molecule to another

83
Q

Transcription

A

Information transferred from DNA to an RNA molecule

84
Q

Translation

A

Information is transferred from RNA to a protein through a code that specify the amino acid sequence

85
Q

Prokaryotes gene expression

A

transcription and translation both occur in the cytoplasm

86
Q

Eukaryotic gene expression

A

Transcription in nuclear then pre-mRNA is processed to mRNA and leaves into the cytoplasm for translation

87
Q

Protein coding RNA

A

mRNA

88
Q

RNA unique to prokaryotes

A

CRISPR RNA (crRNA)

89
Q

Folded complex of RNA called _

A

Hairpin-loops and stem-loops

90
Q

Synthesis in respect to DNA template strand

A

complementary and antiparallel

91
Q

Transcription

A

1) initiation does not require a primer
2) ribonucleotides are added to the 3’OH group of the growing RNA chain
3) DNA unwinds at the front of the transcription bubble
4)rewinds

92
Q

Three requirements of transcription

A

1) DNA template
2) RNA nucleotides (rNTP’s)
3) RNA polymerase and other proteins

93
Q

RNA transcription

A

Template is read in 3’ to 5’ direction, while RNA is synthesized in the 5’ to 3’ direction
ONLY the RNA coding region is transcribed

94
Q

Promoter

A

upstream of the start site, adjacent to gene. Indicates the direction of transcription. Orients the enzyme towards the start site

95
Q

RNA coding region

A

downstream of start site

96
Q

Termination site

A

downstream of start site

97
Q

Initiation (prokaryotic)

A

assembly of transcription apparatus on the promoter and begins synthesis of RNA

98
Q

Elongation (prokaryotic)

A

DNA is threaded through RNA polymerase, unwinds the DNA, ass new nucleotides to the 3’ end of the growing RNA strand.

99
Q

Termination (prokaryotic)

A

the recognition of the end of transcription

100
Q

What do bacteria use to recognize promoters?

A

Sigma factors

101
Q

what would happen without sigma?

A

core enzyme would initiate transcription randomly

102
Q

Holoenzyme

A

in prokaryotes it is the complete enzyme complex composed of the core RNA polymerase and the sigma factor

103
Q

Consensus sequences

A

short stretch of DNA that is conserved among promoters of different genes (prokaryotic thing)

104
Q

Common sequences (or elements)

A

-10 (pribnow box) and -35 nucleotides which are upstream of the start site (+1). They are NOT identical in all promoters

105
Q

Promoter sequences strength =

A

frequency of trasnciription

106
Q

Strong promoter

A

recA

107
Q

Down mutations

A

base substitutions that make the sequence less similar to the consensus sequences reduce the rate of transcription

108
Q

up mutation

A

sequence become more similar to the consensus sequences

109
Q

RNA transcription in prokaryotes

A

is initiated when core RNA polymerase binds to the promoter with the help of sigma

110
Q

Terminators in bacteria

A

Rho-dependent (requires Rho protein) and Rho-independent (also called intrinsic terminator)

111
Q

Rho-dependent termination

A

1) rho bind to RNA upstream of terminator
2) RNA polymerase pauses when it reaches terminator and Rho catches up
3) Rho unwinds DNA-RNA hybrid using helicase activity

112
Q

Rho-independent termination

A

1) inverted repeats
2) polymerase pauses at Us
3) hairpin formation destabilize DNA-RNA hybrid
4) RNA transcript dissociated from RNA polymerase, DNA reanneals

113
Q

Consensus sequences in order for eukaryotic transciption

A

TFIIB (-35), TATA(-25), initiator(+1), and DCE (+30)

114
Q

Core promoter

A

extend upstream/downstream of transcription start site. Minimal sequence required for accurate transcription initiation. Includes a number of consensus sequences

115
Q

Regulatory Promoter

A

located upstream of the core promoter, exact location can be variable. Transcriptional activator proteins binds to consensus sequences and affect the rate of transcription.

116
Q

Order of Basal transcription apparatus assembly

A

TATA binding protein, general transcription factors, basal transcription apparatus

117
Q

What is required for termination

A

cleavage of the mRNA at a specific site

118
Q

What degrades the remaining mRNA terminating transcription?

A

5’ to 3’ exonuclease