30.6.2013(molecular Biology)53 Flashcards
(196 cards)
0
Q
Pentose sugar is attached to nitrogenous base by
A
Beta N glycosidic bond
1
Q
Addition of phosphates to pentose sugar
A
1st phosphodiester bond
2nd and 3rd acid anhydride bond
2
Q
Adenine
A
6-aminopurine
3
Q
Guanine
A
2 amino 6 oxopurine
4
Q
Hypoxanthine
A
6 oxopurine
5
Q
Xanthine
A
2,6 dioxypurine
6
Q
Uric acid
A
2,6,8 trioxypurine
7
Q
Cytosine
A
2 oxo 4 amino pyramidine
8
Q
Uracil
A
2,4 dioxopyramidine
9
Q
Thymine
A
2,4 dioxo 5 methyl pyramidine
10
Q
Nucleoside of hypoxanthine
A
Inosine
11
Q
Pseudouridine
A
Ribose linked to C5 of uracil to form C-C bond
12
Q
Negative charge of DNA is because of
A
Phosphate groups
13
Q
Choline synthesis
A
SAM
Most important methyl donor
14
Q
Sulfate condensed with ATP
A
PAPS
Most important Sulfate donor
15
Q
Major site of denovo purine synthesis
A
Liver
16
Q
Denovo purine synthesis takes place in which organelle
A
Cytoplasm
17
Q
Denovo purine synthesis don’t take place in which sites
A
Brain
RBC
WBC
Solely depend on salvage pathway
18
Q
An enzyme requiring ATP
A
Synthetase
Synthase otherwise
19
Q
Importance of salvage pathway
A
Less energy consuming
Effective recycling of degraded nucleotides
Important in organs where denovo synthesis doesnot take place
20
Q
Product formed by Xanthine oxidase other than Xanthine and Uric acid
A
H2O2
21
Q
Orange sands in urine
A
Lesch nyhan syndrome
22
Q
Diagnosis of Lesch nyhan syndrome
A
HGPRTase level in erythrocytes
23
Q
Kelley seegmiller syndrome
A
HGPRTase deficicent but greater than 1.5-2%
24
Diff btw APRTase defect and Lesch nyhan
Brown spots in diaper
2,8- dihydroxy adenine crystals
Plasma Uric levels normal
Autosomal recessive
25
2,8 dihydroxy adenine is formed by
Xanthine dehydrogenase
26
Other names for SCID
Glanzmann rinker disease
| Bubble boy disease
27
Products of pyramidine degradation
Beta alanine
| Soluble
28
Only naturally occurring beta amino acid
Beta alanine
29
Beta alanine is a part of which vitamin
Pantothenic acid hence a part of coA
30
Nucleoside excreted unchanged in urine
Pseudouridine
31
Pyramidines that form beta alanine
Cytosine
| Uracil
32
End product of thymine metabolism
Beta aminoisobutyrate
33
Megaloblastic Anemia not responding to iron,folate or B12
Orotic aciduria
34
Orotic aciduria
```
Type 1 UMP synthesis defect
Type 2 OMP decarboxylase defect
Type 2 hyperammonemia
Reye syndrome
Allopurinol
```
35
Orotic aciduria in reye syndrome
Mitochondrial damage
| Carbomyl phosphate leaks into cytoplasm where pyramidine synthesis is active
36
Most common defect in urea cycle
Type 2 hyperammonemia
| Ornithine transcarbomylase
37
UAKD
Uromodulin associated kidney disease
38
Uromodulin gene encodes
Tamm horsfall protein
39
Mutations in uromodulin cause
Medullary cystic kidney disease 2
40
Pemetrexed inhibits
Thymidylate synthetase
Dihydrofolate reductase
Glycinamide ribonucleotide formyl transferase
41
Restriction endonucleases
Sticky ends Taq1
| Blunt ends Hae3
42
Blunt ends can be joined by
Ligase produced by bacteriophage T4
43
Vectors
Bacterial plasmids
Bacteriophage lambda
Yeast artificial chromosomes
44
Base pair tilts in DNA
Perpendicular in B DNA
20' in A DNA
9' in Z DNA
45
Number of basepairs per turn
B DNA 10
A DNA 11
Z DNA 12
46
Viscosity in denaturation of DNA
Decreased
47
Absorbance in melting of DNA
Hyperchromicity of denaturation
| Increased absorbance
48
Bacterial topoisomerases are targeted by
Ciprofloxacin
Nalidixic acid
Novobiocin
49
Human topoisomerases are targets for
```
Etoposide
Adriamycin
Doxorubicin
Mitoxantrone
Daunorubicin
Idarubicin
Epirubicin
```
50
Nicking is a _________ reaction
Transesterification
51
Number of ATPs used by topoisomerase 1
None
52
Diff btw topoisomerase 1 and 2
Topoisomerase 2
Double stranded nick
ATP needed
53
DNA gyrase
Topoisomerase 2
54
Human topoisomerases
Relaxes both positive and negative supercoils
55
Histone is rich in
Lysine
| Arginine
56
Number of bp around a histone octamer
146
57
Number of basepairs in linker DNA
30bp
58
H3 and H4 are rich in
Lysine
59
H2A and H2B are rich in
Arginine
60
Chromatin fiber is formed by
6 nucleosomes join together
61
Why DNA is repository of genetic information
RNA is highly susceptible to base catalysed hydrolysis due to its 2 OH group
62
Semiconservative replication of DNA was proved by
Messelson and stahl
63
ORIs
OriC e.coli
Ori lambda in bacteriophage
Autonomous replicating sequences in yeast
ARS in humans also
64
ORC
Origin of replication complex
| Ori+ dsDNA binding protein (DnaA)
65
A-T rich region adjacent to ori in eukaryotes
DNA unwinding element
66
Opening of DNA complex in eukaryotes
Multiple ori
ORC
mini chromosome maintanence protein(MCM)
67
Replication protein A
SSB in humans
68
Removal of RNA primer
DNA polymerase 1(5'-3' exonuclease)
69
Synthesis of Okazaki fragments
DNA polymerase 3
70
Removal of primer in humans
RNAseH
71
Replisome
Helicase
SSB
Primase
DNA polymerase
72
Properties of DNA polymerase
Chain elongation
Processivity
Proof reading
73
Polymerases with proof reading activity
DNA Polymerase 1,2,3
74
Most processive DNA polymerase
3
75
Kornberg enzyme
DNA polymerase 1
76
Klenow fragment
DNA polymerase from which 5'-3' exonuclease activity has been removed
Used in recombinant DNA technology
77
DNA polymerase with repair activity
1>2
78
Length of Okazaki fragments
Eukaryotes 100-150
| Prokaryotes 1000-2000
79
Length of RNA primer
100-200 nucleotide
80
Telomere
Tandem repeat of TTAGG at 3' end of parent DNA
81
Nobel prize for discovery of telomeres
Elizabeth blackburn
Carol.w.Greider
Jack.W.Szostak
82
Repair of double stranded breaks
```
Homologous recombination (S and G2/M)
Non homologous end joining (G0/G1)
```
83
Disorders in nucleotide excision repair
Xeroderma pigmentosum
Cockayne syndrome
Trichothiodystrophy
84
Most common site of HNPCC
Cecum
85
Defect in non homologus end joining repair
SCID
86
Hot spots for mutation
Dinucleotide C-G sequences
87
Defect in homologous recombination
```
ataxia telangiectasia like disorder
Bloom syndrome
Nijmen break syndrome
Werner
Rothmund Thomson syndrome
BRCA1 and BRCA2
```
88
Defect in base excision repair
MUTYH associated polyposis
89
Core enzymes in RNA polymerase
2 alpha
1 beta
1 beta'
Omega
90
Catalytic unit in RNA polymerase
Beta subunit which binds to Mg2+
91
Bacterial promotors
- 10 TATA box
| - 35 TG box
92
Eukaryotic promotors
-25 Goldberg hogness box
-70 to -80 CAAT box
GC box
93
Promotor clearance
Movement of RNA polymerase from promotor region after the mRNA becomes 10 nucleotides long
94
Source of methyl gp for 7 methyl guanosine cap
SAM
95
Poly A tail codes for
Polylysine
96
Sn RNA is rich in
Is uracil rich
| Ribozyme
97
Main splicing enzyme
U2
98
Spliceosome
Snurps+ hnRNA
99
Eukaryotic hn RNA without introns
Histones
100
Site of most of post transcriptional processing
Nucleus
rRNA inside the nucleolus
101
Generation of different IgG
Alternative polyadenylation site
102
Exception to central dogma of molecular biology
RNA editing
103
gRNA
Guide RNA
| aids in RNA editing process
104
Editosome
Unedited mRNA
Guide RNA
anchor proteins
105
SnoRNA
Small nucleolar RNA
| eukaryotic rRNA processing
106
Junk DNA
Molecular parasites
| Codes for introns
107
RNA which contain thymine base
tRNA
108
Stop codons that can code for aminoacids
UGA-Selenocysteine
| UAG-pyrolysine
109
Aminoacids with single codon
AUG- methionine
| UGG-tryptophan
110
Terminator codons
UAA-ochre
UAG-amber
UGA-opal
111
40S subunit
30 proteins
| 18s
112
60s subunit
5s
5.8s
28s
50 proteins
113
Cistron
Smallest unit of genetic expression
| Segment of mRNA which codes for single polypeptide
114
Other name for tRNA
sRNA
| soluble RNA
115
Shape of tRNA
Secondary structure- clover leaf shaped
| Tertiary structure- L shape
116
DHU arm binds to
attaches to Aminoacyl tRNA synthetase
117
Pseudouridine arm
Binds the tRNA to ribosomes
118
Amino acids represented by largest number of codons
6 codons
Serine
Leucine
Arginine
119
Unusual bases in tRNA
Dihydrouracil
Pseudouridine
Hypoxanthine
120
A set of three nucleotides on DNA molecule
Triplet
121
Marker sequence in eukaryotes
Kozak sequence
122
Initiation of protein synthesis
1. Disassembly of ribosomal units
2. Formation of 43s pre initiation complex(40s+ ternary complex)
3. Formation of 48s pre initiation complex(43s+mRNA)
4. Formation of 80s initiation complex (48s+60s)
123
Binary complex
GTP+eIF2
124
Ternary complex
Met tRNA+GTP+eIF
125
Catabolite activator protein is activated by
CAMP
126
In the presence of lactose repressor is inhibited by
Allolactose
127
Arrangement of lac operon
1. LacI
2. promotor
3. operon
4. structural genes
128
Gratuitous inducer
Lactose analogs capable of inducing lac operon
| Isopropyl thiogalactoside
129
Example for gene amplification
Resistance to MTX
130
Diseases caused by transposons
DMD
| Haemophilia
131
Retroposons
DNA segments that move from one location to another through a RNA intermediate
132
Examples for gene switching
Hemoglobins
| Immunoglobulins
133
Types of probes
Radioactive probes
Biotinylated probes
Antibodies
134
Expression library
A library created using expression vector
135
Checkpoint in mitotic phase
Spindle checkpoint
136
Defects in spindle checkpoint
Aneuploidy
137
Restriction point
G1/S
138
Mitochondrial disease with homoplasmy
LHON
| Sensorineural deafness
139
Mitochondrial diseases without maternal inheritance
Pearson
| Kearne sayre
140
Passenger DNA
DNA to be cloned
141
Plasmids can carry how many bp
6-10kbp
142
Phages can carry DNA fragments upto
10-20kbp
143
Cosmids
Plasmids+ cos gene
144
Cosmids can carry DNA fragments of size
30-50kbp
145
DNA insert size
BAC and PAC 50-250kbp
| YAC 500-1000kbp
146
Chimeric DNA
DNA of interest+ vector DNA
147
Successful ligation of DNA in rDNA tech can be detected by
Blue white screen
Cells grown in the presence of galactose
Successful-white
148
Technique used to separate large fragments of DNA
Pulse field gel electrophoresis
149
Gene expression studies
Northern blot
RT PCR
RNA microarray
150
Eastern blotting
Post translational modification
151
Immunoblot
Western blot
152
Zooblot
Southern blot with DNA from different species to detect conserved sequences
153
Dot blot
Slot blot
No nitrocellulose membrane
Directly applied to slots on special blotting apparatus containing nylon membrane
154
Invivo DNA cloning technique
Recombinant DNA technology
155
PCR temperatures
Denaturation 94 C
Annealing 60 C
Taq polymerase 72 C
156
Sanger method
Controlled chain termination method
157
Chain terminators used in Sanger method
2'3' dideoxynucleotides
158
DNA polymerse used in Sanger technique
Klenow polymerase
159
DNA sequencing technique
Maxam and Gilbert method
| Sanger technique
160
Pseudo gene
An inactive segment of parental active gene that donot code for a functional gene
161
Processed gene
An area of gene that has the same complementary strand as a full mRNA
162
Selfish DNA
DNA sequences that appear to have little function in genome
163
Null allele
A mutation that lead to complete loss of function
164
GINA
Genetic information nondiscrimination act
Came to effect in 2008
165
Quantitative PCR
Real time PCR
166
SYBR green dye is used for
quantitative PCR
167
Silent mutation
Synonymous mutation
168
Conservative mutation
Missense mutation in which one aminoacid is replaced by a similar amino acid
169
Hot spot for deletion
DMD gene
170
Knights move pattern is seen in
X linked recessive
171
Y chromosome contains
SRY
DAZ(deleted in azoospermia)
AZF(azoospermic factor gene)
172
Hemizygous state
X linked disorder in male
173
X chromosome belongs to
Group C
174
Y chromosome is found in group
G
175
X chromosome
Large submetacentric
176
Most common type of chromosome
Submetacentric
177
Longest and smallest chr
```
Chr1
Chr 22(smallest)
```
178
4p deletion
Wolf hirschhorm syndrome
179
Facies in wolf hirschhorm syndrome
Greek helmet
180
Types of deletion
Interstitial
| Terminal
181
Most common isochromosome
Xq seen in turner syndrome
182
Preimplantation analysis
Blastomere analysis
183
Ideal time for chromosome analysis
Prophase or prometaphase(more banding can be done)
184
In G banding chromosomes are treated by
Trypsin
185
Other name for G banding
GTG banding
186
In R banding chromosomes are denatured by
Heat
187
R banding is used for
Detecting terminal rearrangement
188
C banding
Centromeric heterochromatic banding
189
C banding
Pretreated by acid followed by alkali
190
Q banding is
Quinacrine mustard
191
Banding detected by fluorescence microscopy
Q banding
192
FUdR banding
Flurodeoxy banding
| Detection of folate sensitive fragile sites
193
NOR banding
Nucleolus organising region
194
Random inactivation takes place on
16th day(blastocyst)
195
MSY
Male specific Y
| Rich harvest of gene from Y chromosome
