CYTOGEN 2ND TRINAL Flashcards
1
Q
Transcription
A
DNA to mRNA
2
Q
Replication
A
DNA to DNA
3
Q
- Reverse Transcription
A
RNA to DNA
4
Q
- Translation
A
RNA to Protein
5
Q
do most of the work in the cell
A
PROTEINS
6
Q
two DNA copies are produced from one original DNA
A
- Conservative Replication
7
Q
Two DNA copies are produced with one new strand and the other strand from the old DNA
A
- Semiconservative Replication
8
Q
where the flow of information in the cell starts
A
DNA
9
Q
BASIC REQUIREMENTS FOR REPLICATION
A
- Substrates
- Template
- Enzymes and Proteins
10
Q
- the four deoxyribonucleoside triphosphate
A
dATP
dGTP
dCTP
dTTP
11
Q
- Both the strands of __________ serve as template for the synthesis of new daughter cells
A
DNA Double helix
12
Q
- DNA Replication Key Enzymes
A
o Helicase
o DNA Polymerase
o Primase
o Ligase
13
Q
o Unwinds the DNA
A
- DNA B Protein (Helicase)
14
Q
o Guides DNA polymerase on where to start
A
- Primase
15
Q
o Relieves torsional strains by cutting & joining single-strand or both strands
A
- DNA topoisomerase I & II
16
Q
o DNA chain elongation
o Finishes nucleotide sequence
A
- DNA Polymerase
17
Q
o Joins okazaki fragments
o Glue fragments
A
- DNA Ligase
18
Q
o Initiates where the origin of replication
A
- DNA A Protein
19
Q
o Binds and separates single stranded DNA and stabilizes after helicase separates it.
A
- SSB (Single strand Binding Protein)
20
Q
o Prevents the helicase from further unwinding and signals termination
A
- Ter Binding Protein
21
Q
- The DNA synthesis is catalyzed by enzyme called DNA dependent DNA polymerase called a
A
primase
22
Q
o DNA chain elongation is always
A
5’ to 3’ direction
23
Q
o DNA repair
A
5’ to 3’ exonuclease activity
24
Q
o Proofreading
A
3’ to 5’ exonuclease activity
25
TYPES OF POLYMERASES
* Polymerase in prokaryotes
* Polymerase in eukaryotes
26
* Polymerase in prokaryotes
o DNA polymerase I
proofreads
o DNA polymerase II
o DNA polymerase III
Starts the primers
27
* Polymerase in eukaryotes
o DNA polymerase alpha
o DNA polymerase epsilon
o DNA polymerase beta
o DNA polymerase delta
o DNA polymerase gamma
27
* Synthesized by DNA dependent RNA polymerase called primase (in a 5’ to 3’ direction) using DNA as a template
RNA PRIMER
28
is a short piece of RNA required for synthesis of DNA
Primer
29
o RNA is made up of
RNA
30
STEPS OF DNA REPLICATION
* Initiation
* Elongation
* Termination
31
* Termination
o I. helicase unwinds DNA
o II. SSB proteins bind to DNA strands
o III. Primase creates primer
o IV. DNA polymerase begins to build
o V. Ligase fills in the lagging strand
o VI. Ter binding protein signals helicase to
stop unwinding
32
* Simultaneous
INITIATION
33
* Eukaryotes start at multiple sites compose solely of A-T Base pairs which are called
consensus sequence
34
o One round of synthesis involves _________ nucleotides per strand which completes in about 40 min.
4 million
35
* The place where the DNA replication starts
ORIGIN
36
* ____________ recognizes and binds to the “Ori” of the DNA and denature (breaks down) DNA
DNA A protein
37
________ binds to this region and unwinds two complementary DNA strands
Helicase
38
– the “V” or “Y” shaped structure resulting from the unwinding of the helicase.
* Replicating fork
39
keeps the two strands away from each other after the helicase unwinds it.
SSB
40
releases the tensions produced by supercoiling.
* Topoisomerases
41
o Relaxes the “backbone”
* Topoisomerases
42
– provides structural support for DNA and RNA
o Sugar-phosphate backbone
43
– takes place and signals DNA polymerase to start building
o Primase
44
forms complex with proteins called __________ which can recognize specific site for synthesis of RNA primer.
primosome
45
* DNA polymerase III initiates the creation of new DNA strand by adding deoxyribonucleotide to the 3’ end of the RNA primer.
ELONGATION
46
o DNA polymerase works in a _________direction, because it can only add nucleotides to the 3’ end.
5’ to 3’
47
* Only in 5’ 3’ direction which becomes the __________
leading strand
48
o The DNA chain which runs in the 3’ to 5’ direction is copied by polymerase III as a ________________, requiring one primers.
continuous strand
49
o Runs in the 5’ to 3’ prime direction
o Copied by polymerase III in a discontinuous manner because creation can only proceed in the 5’ to 3’ manner.
o Requires numerous RNA primers
Lagging Strand
50
* Short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication
OKAZAKI FRAGMENTS
51
– an enzyme that connects two okazaki fragments into one continuous strand.
* Ligase
52
– discovered (1930-1975)
* Reiji Okazaki
53
– a specific protein that binds the sequences and prevents the helicase from unwinding the DNA
* Ter binding protein
54
* DNA is copied by DNA polymerase with high accuracy
PROOFREADING
55
o Widely used as antibiotics for treating urinary tract infections & other infections.
Prokaryotic topoisomere
56
o Widely used as anticancer drugs
* Human topoisomerase
57
* The process of creating mRNA from DNA is called ____________
transcription.
58
During ___________, a specific segment of DNA is "read," and a complementary mRNA molecule is synthesized.
transcription
59
is synthesis of single stranded RNA from a double stranded DNA template. It produces messenger RNA (mRNA).
* Transcription
60
A molecule that carries the code (sequence of nucleotide bases) that corresponds to a specific protein.
mRNA
61
is the 1st stage of protein biosynthesis from RNA. In this process formation of polypeptide by using mRNA as template. It occurs in ribosomes.
Translation
62
is the first step leading to gene expression
* Transcription
63
HETEROCHROMATIN structures
Condensed structure
Transcriptionally inactive:
Rich in Repetitive Sequences:
64
It appears as dark, dense regions when stained for microscopic observation
Condensed structure
65
genes within heterochromatin regions are typically not being actively transcribed or expressed. It contains genes that are permanently turned off or silenced
Transcriptionally inactive
66
EUCHROMATIN
Relaxed structure:
Transcriptionally active
Gene-Rich:
Dynamic state
67
euchromatin is less condensed and appears as lighter, less dense regions when stained for microscopic observation
* Relaxed structure:
68
euchromatin is generally__________________ containing genes that are actively transcribed and expressed to perform various cellular functions
transcriptionally active
69
euchromatin is rich in protein-coding genes, regulatory elements, and other sequences involved in gene expression and regulation
* Gene-Rich:
70
euchromatin can change its state depending on the cell’s needs. Genes in euchromatin can be turned on or off in response to environmental cues, developmental stages, and other factors
* Dynamic state:
71
binds to specific DNA region and initiate transcription called as promoter site
* RNA polymerase
72
is the enzyme responsible for transcription. It has 5 subunits: - 2αsubunit, βsubunit, β’subunit, ω subunit.
* RNA polymerase
73
INITIATION
RNA polymerase
74
* RNA polymerase moves along DNA template and sequentially synthesizes the RNA chain
ELONGATION
75
* Transcription stops when RNA polymerase reaches a section of DNA called the
terminator
76
* Terminator sequence=
AAUAAA
77
* The original transcript from the DNA is called as
pre-m RNA.
78
* It contains transcript of both intron and exons
RNA Processing
79
it is non-coding sections of nucleic acid found between coding regions
* INTRON:
80
coding regions of nucleic acids
* EXONS:
81
* The introns are removed by a process called __________to produce messenger RNA (mRNA)
splicing
82
is a process in which the formation of polypeptide (PROTEIN) by decoding mRNA produces in transcription
* Translation
83
* 4 PHASES in translation
INITIATION
ELONGATION
TRANSLOCATION
TERMINATION
84
* This stage of translation brings together mRNA, tRNA bearing the 1st amino acid of the polypeptide, and 2 subunits of a ribosomes
initiation
85
* The tRNA has a amino acid linked to its term as
charged tRNA
86
* In this amino acid are added one by one to the first amino acid called as
amino acid delivery
87
* The tRNA with the polypeptide chain in the A site is translocated to the P-site, tRNA at the P site moves to the E site and leaves ribosome
3. TRANSLOCATION
88
* Protein factors called release factors interact with the stop codons and cause release of the completed polypeptide chain
TERMINATION
89
* Stop codon:
UAA, UAG, UGA
90
Start codon:
AUG
91
* Start anticodon:
UAC
92
TRANSLATION in Eukaryotes
INITIATION
ELONGATION
TERMINATION
93
Ala-A
alanine
94
arg-R
arginine
95
asn-N
asparagine
96
asp-D
aspartic acid
97
cys-C
cysteine
98
glu-E
glutamic acid
99
gln-Q
glycine
100
his-H
histidine
101
ile-I
isoleucine
102
leu-L
leucine
103
lys-K
lysine
104
met-M
methionine
105
phe-F
phenylalanine
106
pro-P
proline
107
ser-S
serine
108
thr-T
threonine
109
trp-W
tryptophan
110
tyr-Y
tyrosine
111
val-V
valine
112
non-essential amino acid
alanine
arginine
aspartic acid
cysteine
glutamic acid
glutamine
glycine
proline
serine
tyrosine
asparagine
113
essential amino acid
histidine
isoleucine
leucine
lysine
methionine
phenylalanine
threonine
tryptophan
valine
