Topnotch 2 Flashcards
1
Q
Protein turnover per day
A
200-300/day
2
Q
Protein degradation mechanism inside the cell, using non energy dependent degradative enzyme
A
ubiquitin proteosome mechanism
3
Q
Manner of excretion of excess nitrogen by humans
A
Ureotelic
using urea
4
Q
2 steps in Nitrogen removal
A
- Transamination
2. Oxidative Deamination
5
Q
All amino acids must transfer amino groups to a-ketoglutarate except for (2)
A
Lysine
Threonine
6
Q
Coenzyme of ALT and AST
A
Vit B6 (Pyridoxine)
7
Q
Asp acted by AST –>____
A
oxaloacetate
8
Q
Ala acted upon by ALT —> _____
A
pyruvate
9
Q
where oxidative deamination occurs
A
LIVER and KIDNEY only
10
Q
Removal of excess N from peripheral tissues is through
A
GLUTAMINE
garbage collector
11
Q
where urea cycle occurs
A
liver
12
Q
Donors of atoms of Urea
A
NH3 from ammonia
NH3 from aspartate
CO2
13
Q
Enzyme in rate limiting step of Urea cycle
A
CPS-I
Carbamoyl Phosphate Synthase I
14
Q
Reactions in Urea Cycle
A
Ordinary Careless Crappers Are Also Frivolous About Urination
Ornithine +
Carbamoyl Phosphate= Citruline
Citruline
+ Aspartate –>Arginosuccinate
Fumarate + Arginine
Arginine = Urea + Ornithine
15
Q
Energy requirement of urea cycle
A
4 ATPs
16
Q
Enzyme defect in Hereditary Hyperammonemia Type I (most common), presenting with lethargy, vomiting, coma and death
A
CPS I
17
Q
Enzyme defect in Hereditary Hyperammonemia Type II
A
Ornithine transcarbamoylase
18
Q
Purely ketogenic amino acids
A
Leucine
Lysine
19
Q
Amino acids both ketogenic and glucogenic
A
Phenylalanine
Tyrosine
Tryptophan
Isoleucine
FYI, W
20
Q
Yield by ketogenic amino acid metabolism
A
acetoacetate
acetyl CoA
21
Q
Entry point in Krebs is Fumarate
A
Phenylalanine and Tyrosine
22
Q
Entry point in Krebs of
Glutamine, Glutamate, Proline, Arginine, Histidine
A
a ketoglutarate
23
Q
Entry point in Krebs of Methionine, Valine. Isoleucine, Threonine
A
Succinyl CoA
24
Q
Entry point in Krebs is oxaloacetate
A
Aspartate, Asparagine
25
Amino acid Glycine is made from
Serine
26
Proline is synthesized from
Glutamine
27
Serine is synthesized from
3-phosphoglycerate
28
Cofactor of Phe hydroxylase hence deficiency can manifest like PKU
Tetrahydrobipterin
29
Alkaptonuria is due to congenital deficiency of _____
Homogentisic Acid Oxidase
| in the degradative pathway of Tyrosine
30
darkening of connective tissue seen in alkaptonuria
ochronosis
31
congenital deficiency of TYROSINASE or defective TYROSINE transporters
Albinism
32
Occurs to either:
cystathionine synthase deficiency
or its dec affinity for Vit B6
homocysteine methyltransferase deficiency
homocystinuria
33
Causes downward and inward lens subluxation, tall stature, MR
Homocytinuria
34
Defect of tubular amino acid transporter for COLA
cystinuria
35
Treatment of Cystinuria
Acetazolamine (to alkalinize the urine)
36
Enzyme deficient in MSUD
a-ketoacid dehydrogenase
37
Predominant sites of heme synthesis
Liver
| Bone marrow
38
Rate limiting step of Heme Synthesis
Formation of delta aminolevulinic acid
| catalyzed by ALA synthase
39
Co-factor of ALA synthase (*heme synthesis)
pyridoxine
40
Photosensitivity
Abdominal pain
Neuropsych symptoms
Most common porphyria
porphyria cutanea tarda
41
reaction heme synthesis
glycine + succinyl CoA ---> d-aminolevulinic acid
42
Enzyme of heme synthesis inhibited by zinc
ALA dehydratase
| in the formation of porphobilinogen
43
Heme synthesis, start of the RING
Uroporphyrinogen
44
Enzyme of heme synthesis inhibited by lead
ferrochelatase,
| ALA dehydratase
45
How is heme formed
(Fe 3+) into protoporphyrin IX
| by heme synthase
46
Blood picture pyridoxine deficiency associated with isoniazid therapy
Sideroblastic anemia with ringed sideroblasts
47
Wrist drop, claw hand
| basophilic stippling RBC
lead poisoning
48
start of photosensitivity enzyme heme synthesis
Uroporphyrinogen decarboxylase
49
Glucoronic acid + N acetyl glucosamine
Hyaluronic acid
50
GAG Vitreous humor, synovial fluid
Hyaluronic acid
51
GAG Glucoronic acid + N acetyl galactosamine
Chondroitin Sulfate
52
GAG Iduronate + Glucosamine
Heparin
53
All GAGs covalently attached to protein to form proteoglycans except
Heparin
54
GAG in endochondral bone also cartilage
chondroitin sulfate
55
GAGs role in corneal transparency
Keratan sulfate I
| Dermatan sulfate
56
GAG impt in charge of glomerulus
Heparan sulfate
57
GAG cell migration in wound repair
| compressibility of cartilage
Hyaluronic acid
58
Where GAGs are synthesized
ER
| by acid hydrolases
59
Accumulation of GAGs in lysosomes due to deficiency in hydrolases
Mucopolysaccharidoses
60
Mucopolysaccharidoses all are autosomal recessive except
Hunters
| X linked recessive
61
Mucopolysaccharidoses all have MENTAL RETARDATION except
Morquio's syndrome
62
Deficient in Morquio's syndrome
galactose-6-sulfatase
63
Deficient in Hurler's syndrome
a-L-iduronidase
64
Type II Mucopolysaccharidoses
Sanflippo syndrome
| so many!! refer to p 7 handout 2
65
Function of glycoproteins
cell recognition
| cell antigenicity
66
Deficient phosphorylation of mannose residues in N linked glycoprotein pre enzymes
I-cell disease
67
protein HIV
gp120 + p41
68
Malaria glycoprotein
GPI
69
Type A glycosphingolipids
N acetyl galactosamine
70
Type B glycosphingolipids
Galactose
71
of AAs in insulin
51
72
where the 3 disulfide bonds in insulin is found
A7 -B7 - interchain
A20- B19- interchain
A6-A11- intrachain
73
sperm receptor
zP3
74
Glucagon receptor
Gs
| inc cAMP
75
nutrients requirement 50% of healthy individuals
Estimated Average Requirement
76
nutrients requirement 95% of healthy individuals
Rec Daily Allowance
77
Estimated energy requirement
| Sedentary/ Moderately Active/Very Active
30/ 35/ 40
78
Basal Metabolic Rate
60%
79
Form of Vit A growth regulators in epithelium
retinoic acid
80
Form of Vit A gametogenesis in gonads
retinol
81
Form of Vit A rod and cones cells for vision
retinal
82
Toxicity of Vit A
Hyperkeratosis
Hepatomegaly
Pseudotumor cerebri
83
active form Vit D
Calcitriol (1,25 (OH) Vit D2)
84
Vit D3 hydroxylated 2x how
25 hydroxylation in liver
| 1 hydroxylation in kidney
85
Long QT. Calcium is?
low
86
Most toxic vitamin
Vitamin D
87
Synthetic Vit K
Manadione
88
Vit K given to newborns
K1 Phylloquinone
89
Vitamin transketolase reactions in HMP
Thiamine
90
Vitamin def
confusion
loss of muscle coordination
Wernickes
91
Vitamin def
inability to form new memories
confabulation
Korsakoff
92
Vitamin in FAD
Riboflavin (Vit B2)
93
Vit def stomatitis
| cheilosis
Vit B2
94
Vitamin can be derived from Trp
Niacin
95
Trp in carcinoid syndrome
increase Trp metabolism
96
Trp in Hartnup Disease
Dec Trp absorption
97
Vitamin used as cofactor for acyl transfers
Pantothenic acid
98
Vitamin no deficiency state
Vit B2, B5
99
Vitamin used for methionine synthesis
Vit B12
100
Vitamin cofactor by dopamine hydroxylase
Vit C
101
Deficiency of this Vitamin is induced by AVIDIN in egg whites
Biotin
102
Inhibits dihydropteroate synthase
sulfonamides (sulfamethoxazole)
103
Inhibits dihydrofolate reductase
trimethoprim
104
Isoniazid is activated by Phase I or Phase II reaction?
Phase II (Acetylation)
105
Link in NucleoSIDE between sugar and purine/pyrimidine
B-N-glycosidic bond
106
Nucleoside with phosphoryl group at C5
nucelotides
107
Purine synthesis
| Source of atoms
```
Glutamine
Aspartic Acid
Carbon Dioxide
Glycine
THF
(GAC + GT)
```
108
Pyrimidine synthesis
| Source of atoms
Glutamine
Aspartic Acid
Carbon Dioxide
(GAC)
109
Committed step in De Novo Purine Synthesis
PRPP ---> 5-phosphoribosylamine
| catalyzed by glutamyl PRPP amidotransferase
110
Parent purine nucleotide catalyzed in NINE steps
IMP
111
source of ribose 5 phosphate in purine salvage pathway
PRPP
112
Salvage pathway enzyme adenine to AMP
adenine phosphoribosyltransferase (APRT)
113
Salvage pathway enzyme guanine to GMP
Hypoxanthine Guanine phosphoribosyltransferase
114
Salvage pathway enzyme hypoxanthine to IMP
Hypoxanthine Guanine phosphoribosyltransferase (HGPRT)
115
Rate limiting step of De Novo Pyrimidine Synthesis
CPS II
116
Which of the CPS is found in cytoplasm?
| mitochondria?
mitochondria CPS I (urea cycle)
| cytoplasm CPS II (pyr synthesis)
117
Inhibits CPS II
UTP
118
Hyperuricemia
MR
Self Mutilation
Lesch Nyhan
119
parent pyrimidine
OMP
| orotidine monophosphate
120
Steps pyrimidine de novo synthesis
:)
OMP --OMP decarboxylase--> UMP
CTP synthase: UTP and CTP
dUMP -thymidylate synthase - dTMP
121
Thymineless death
5-FU
122
enzyme for reduction of nucleosides to DEOXY forms
ribonucleotide reductase
123
Enzyme which regenerates the reduced forms of ribonucleotide reductase
thioredoxin
124
reconverts thioredoxin to reduced form
NADPH
125
action xanthine oxidase
xanthine to uric acid
126
Products of pyrimidine degradation
B-alanine
| B-aminoisobutyrate
127
PABA analogs
sulfonamides
128
explain the purine overproduction in Von Gierke
deficiency in glucose-6-phosphatase, hence glu-6-P is shunted to generation of PRPP precursor r-5-P
129
Pathophysiology of ADA deficiency
ADA is for Adenosine to inosine
| deficiency: very high dATP which inhibits ribonucleotide reductase
130
abnormal growth
megaloblastic anemia
excrete orotate
orotic aciduria
131
Right handed helix with 10 residues per 360 deg
B DNA
132
Right handed with 11 base pairs per turn
A DNA
133
left handed helix 12 base pairs per turn
z DNA
134
Amino acids high in nucleosome
Arginine
| Lysine
135
densely packed
| transcriptionally inactive chromatin
heterochromatin
136
transcriptionally active chromatin
| stains less densely
euchromatin
137
Blot for DNA
southern blot
RNA- Northern
Protein- Western
138
Dx tool for single base changes
| deletion/ insertion
Restriction Fragment Length Polymorphism
139
Enzyme DNA leading strand synthesis prokaryotes and eukaryotes
DNA pol III iin 3' to 5'
140
Prokaryotic DNA synthesis removes the RNA primers through its 5'-3' exonuclease activity, gap filling
DNA pol I
141
Prokaryotic DNA synthesis Nicks between okazaki fragments
DNA ligase
142
Prokaryotic DNA synthesis
| Recognizes the origin of replication
DNA A protein
143
Prokaryotic DNA synthesis
| maintains separation of parental strand after action of DNA helicase ( which unwinds DNA)
single stranded DNA binding proteins
144
Prokaryotic DNA synthesis
| removes supercoils
DNA topoisomerase
145
DNA proof reading and repair
DNA pol II
146
highly repetitive DNA found at ends of chromosomes
telomeres
147
mismatch repair
HNPCC
148
Thymine dimers defect
xeroderma pigmentosum
149
post transcriptional modifications
poly A tail
methylguanosine cap
splicing
150
post transcriptional modifications
poly A tail
methylguanosine cap
splicing
151
In transcription: where the RNA polymerase holoenzyme binds
Pribnow box (prokaryotes) 8-10 nucleotides left
-35 sequence 35 bases left
TATA or Hogness box, CAAT, GC box (eukaryotes)
152
In transcription: how is it terminated
1. by RNA pol alone (palindrome, hairpin loop)
| 2. rho factor binds at newly syn RNA
153
intervening sequence in synthesized DNA
intron
154
RNA polymerases in eukaryotes (as there are 3, unlike in prokaryotes)
RNA pol I- large rRNAs
RNA pol II- mRNAs
RNA pol III- tRNAs
155
RNA polymerases in eukaryotes (as there are 3, unlike in prokaryotes)
RNA pol I- large rRNAs
RNA pol II- mRNAs
RNA pol III- tRNAs
156
structural genes coding for group of proteins required for a particular function
operon
157
of Codons
64 codons
158
Translation: Stop codons
UAA
UGA
UAG
159
Translation: how is it initiated?
after charging,
initiation factors eIFs assemble the 40s ribosome and initiator tRNA (methionine)
eukaryotes 60s + 40s --> 80s
prokaryotes 50s + 30s --> 70s
160
Translation: how is it initiated?
after charging,
initiation factors eIFs assemble the 40s ribosome and initiator tRNA
eukaryotes 60s + 40s --> 80s
prokaryotes 50s + 30s --> 70s
161
Translation: catalyzes peptide bond formation
peptidyltransferase
162
Translation: how is it terminated?
when a stop codon binds to the A site
163
proteins defective/ meant for degradation is bound to
ubiquitin
164
Antibiotic preventing binding of tRNAs to A site
Tetracycline
165
Antibiotic preventing binding of tRNAs to A site
Tetracycline
166
Antibiotic inhibiting peptide bond formation (transpeptidase)
chloramphenicol
167
Antibiotic binds to 50s inhibiting translocation
Clindamycin
| Erythromycin
168
Antibiotic
| Binds to DNA dep RNA pol thus inhibiting RNA synthesis
Rifampicin
