11. Kevin Bryan Reviewer Flashcards
1
Q
organelle responsible for packaging proteins
A
golgi apparatus
2
Q
organelle - ATP production
A
mitochondria
3
Q
Unfolding of a molecule ≈ effects in entropy
A
large increase ÎÎ in entropy
4
Q
decrease the activation energy of rxn
A
enzymes
5
Q
the lower the Km of an enzyme ≈ effect on affinity
A
higher affinity
6
Q
competitive inhibition can be overcome by
A
increasing the substrate
7
Q
site of ETC (electron transport chain)
A
mitochondria
8
Q
cyanide inhibits what COMPLEX of ETC?
A
Complex 4
9
Q
Blocks electron transport and ATP synthesis by inhibiting the exchange of ATP and ADP across the inner mitochondrial membrane
ATP ADP
A
atractyloside
10
Q
catalyzes rxn that yields wate and hydrogen peroxide
A
superoxide dismutase
11
Q
- unpaired electron
- persist for short period of time
- ex. superoxide dismutase
A
free radicals
12
Q
glucose and galactose are epimers on
A
carbon 4
13
Q
glucose and mannose are epimers on
A
carbon 2
14
Q
Blocks electron transport and proton pumping at Complex III
A
azide
carbon monoxide
15
Q
Blocks electron transport and proton pumping at Complex I.
A
rotenone
16
Q
Blocks ATP synthesis without inhibiting electron transport by dissipating the proton gradient
A
DNP
17
Q
Blocks electron transport and proton pumping at Complex II.
A
antimycin A
18
Q
can be lethal because it binds to the ferric form of cytochrome oxidase and thereby inhibits oxidative phosphorylation
A
cyanide
19
Q
mechanism for nitrite as an antidote to cyanide
A
Nitrite converts ferrohemoglobin into ferrihemoglobin, which also binds cyanide. Thus, ferrihemoglobin competes with cytochrome oxidase for cyanide. This competition is therapeutically effective because the amount of ferrihemoglobin that can be formed without impairing oxygen transport is much greater than the amount of cytochrome oxidase.
20
Q
- higher Km
- not easily saturated
- isoenzyme of hexokinase
- ACTIVE in fed state
A
glucokinase
21
Q
T/F
Acety Coa can be converted to pyruvate in gluconeogenesis
A
FALSE
Fatty acids and ketogenic amino acids cannot be used to synthesize glucose. The transition reaction is a one-way reaction, meaning that acetyl-CoA cannot be converted back to pyruvate. As a result, fatty acids can’t be used to synthesize glucose, because beta-oxidation produces acetyl-CoA.
•Acety CoA - oxidized to CO2and H2O in TCA cycle
•used to synthesize cholesterol
•used to synthesize ketone bodies
22
Q
5 cofactors of alpha ketoglutarate
A
- Thiamine pyrophosphate (derived from thiamine)
- flavin adenine dinucleotide (derived from riboflavin)
- lipoic acid (derived from lipoic acid)
- pantothenic acid as part of Coenzyme-A (CoA)
- nicotinamide adenine dinucleotide NAD+ (derived from niacin
23
Q
which of the following enzymes catalyze a rxn that yield FADH2 in citric acid cycle
A
succinate dehydrogenase
24
Q
which TCA cycle intermediate participates in heme formation
A
succinyl CoA
25
Heme formation
| •co-factor of the committed step
vitamin B6
26
the intermediate that links gluconeogenesis and ketogenesis in the liver
pyruvate
27
```
glucose 6 phosphate participates in all processes except
•pentose phosphate pathway
•gluconeogenesis
•ketogenesis
•glycogenolysis
```
ketogenesis
28
```
these processes occur inside the mitochondria except
•pentose phosphate pathway
•TCA cycle
•beta oxidation
•ketogenesis
```
pentose phosphate pathway
29
what is the mechanism of hypoglycemia in acute ethanol intoxication
conversion of PYRUVATE to lactate
30
branching enzyme of glycogen metabolism is
glycogen branching enzyme AKA
amylo-(1,4→1,6)-transglycosylase
•branching enzyme that catalyzes the transfer of alpha-1,4-linked glucosyl units from the outer end of a glycogen chain to an alpha-1,6 position on the same or a neighboring glycogen chain.
31
is a state of glucose 6 phosphatase deficiency
Von Gierke’s
32
T/F
| glycogenolysis occurs in muscle
TRUE
33
glycogen phosphorylase catalyzes the cleavage of glycogen to yield
glucose-1- phosphate
34
* ptx with deficiency of glycogen phosphorylase in the liver
* expected manifestations EXCEPT:
* hepatomegaly
* ketosis
* lactic acidosis
* marked hyperglycemia
FALSE-
| •marked hyperglycemia
35
deficiency of glycogen phosphorylase is
Hers’ disease
36
glycogen storage disorder associated with hyperuricemia
Von Gierke’s disease
37
enzyme deficient in Von Gierke’s disease
glucose 6 phosphatase
38
pregnant woman with classic galactosemia
| •at risk for
premature ovarian failure
39
High fructose in diet is unhealthy because if is metabolized faster than glycose because it bypasses step catalyzed by
phosphofructokinase 1
40
* night sweats and tremors after fruit juice ingesiton
* (+) fructose in urine
* enzyme deficieny?
aldolase A
41
metabolic consequences of aldolase A deficiency
* INCREASE FRUCTOSE 1 phosphate levels
* hyperuricemia
* allosteric inhibition of glycogen phosphorylase
* depletion of ATP
42
which sugar contribute to cataract formation
sugar alcohol
43
which causes flatulence in lactose intolerance
bacteria in the gut
44
the main FATTY ACID in coconut milk
lauric acid
45
trans fats are manufactured by altering SATURATED fats usig
hydrogenation
46
end product of FATTY ACID synthsis
palmitic acid
47
what is the mechanism behind FATTY LIVER in chronic alcohol use
inc ÎÎ NADH prevents fatty acid oxidation forming triacylglycerols
48
ketone bodies
acetone
acetoacetate
beta hydroxybutyrate
49
steroid nucleus has ___ carbons
17
50
steroid nucleus resembles this ring
phenanthrene ring
51
cholesterol has a side chain at position
17
52
the consumption of cholesterol should be only up to ___ mg per day
300 mg
53
WELL FED STATE ≈ effect HMG-CoA reductase
HMG-CoA reductase - dephosphorylated
54
fate of short and medium chain FA after digestion
absorbed in the hepatic portal vein
55
Apolipoprotein C-II functions in breakdown of
VLDL and chylomicrons
56
which apoprotein is closely associated with alzheimer’s disease due to its capacity to avidly bind to beta amyloid plagues
Apo E-4
57
what is the basis of intestinal expression of apo B-48 lipoprotein
tssue specific RNA editing puts a stop to apoB mRNA translation
58
this component is responsible for transfer of CHOLESTEROL from tissues to other lipoproteins into HDL as esterified cholesterol allowing it to function in REVERSE CHOLESTEROL TRANSPORT
LCAT
59
T/F
•hypothyroidism
•diabetes mellitus
•nephrotic syndrome
-all are associated with abnormal lipoprotein patterns
TRUE
60
what familial disorder of lipoprotein metabolism has elevated levels of LDL
type 2
61
which familial lipoproteinemia gives
HIGH : chylomicron and VLDL
LOW : HDL, LDL
Type 1
62
```
presents as •overproduction and increased levels of VLDL
•glucose intolerance
•associated with coronary heart disease
•type 2 DM
•obesity
```
familial hypertriglyeridemia
63
ASA given low dose for coronary artery disease exerts its beneficial effect by
inhibition of cyclooxygenase required for synthesis of THROMBOXANE
64
product of lipid metabolism —> platelet aggregatiion
TXA2
65
most basic amino acid
arginine
66
this enantiomer of amio acids naturally occur in proteins
L amino acids
67
amino acids - containign phenol ring
tyrosine
68
formation of GABA from glutamic acid is through
glutamic acid —» GABA
decarboxylation
69
which cofactor is necesary for this rxn
| glutamic acid ——» GABA
decarboxylation
pyridoxal phosphate
70
gluthathione is synthesized in the body using
glutamate
glycine
cysteine
71
AA responsible for antioxidant properties of gluthatione
cysteine
72
```
AAs that participate in synthesis of muscle creatine and subsequent breakdown into creatinine
EXCEPT :
a. alanine
b. glycine
c. arginine
d. methionine
```
a. alanine
GAM ≈ creatinine
73
a section of protein sufficient to perform a particular task
domain
74
myoglobin has ___ domain/s
1 domain
75
major component of most connective tissues
collagen
76
nitric oxide is vasodilator derived from
arginine
77
which mediators act on NMDA receptor
glutamate
78
T/F
| Pregnancy is a state of negative nitrogen balance
FALSE
79
major process involved in metabolism of amino acids
transamination
80
major coenzyme for transamination to form amino acids
vit B6
81
AA that can be synthesized from intermediates of the TCA cycle EXCEPT
a. aspartate
b. proline
c. phenylalanine
d. glumate
phenylalanine
TCA = aspartate, proline, glutamate
82
glucogenic amino acids
```
Alanine
Arginine
Asparagine
Aspartic acid
Cysteine
Glutamic acid
Glutamine
Glycine
Histidine
Methionine
Proline
Serine
Valine
```
83
Amino acids that are both glucogenic and ketogenic
```
Amino acids that are both glucogenic and ketogenic (mnemonic "PITTT"):
Phenylalanine
Isoleucine
Threonine
Tryptophan
Tyrosine
```
84
ketogenic amino acids
leucine
| lysine
85
Methionine can be metabilized and enter into TCA cycle as this intermediate
succinyl choline
86
in methylmalonic acidura there is failure to metabolize this amio acids :
•methionine, threonine, isoleucine and valine;
M, T, I, V
•as a result methylmalonic acid builds up in the blood and tissues.
87
an allosteric activator making carbamoyl phosphate 1 active only with its presence
N-acetyl-glutmate
88
direct nitrogen donors in ureal cycle
aspartate
| ammonia
89
MAJOR nitrogen source for urea synthesis
glutamate
90
hyperammonemia type 1 is enzyme deficiency of
carbamoyl phosphate synthase 1
91
what is considered the most common urea cycle disorder
ornithine transcarbamylase deficiency
92
the metabolic intermediate linking urea cycle to the TCA cycle
fumarate
93
what happens to amino acid metabolism in uncontrolled DM
ÎÎ transamination rxns
94
which among the following is considered the most severe of the urea cycle disorders
carbamoyl phosphate synthase 1 deficiency
95
* newborn - upon delivey, suddenly develops: •irritability, lethargy, hypothermia, and intermittent apnea
* lab examination: ÎÎ ammonia levels, ÎÎ citrulline
* what enzyme is deficient
argininosuccinate synthetase
96
* 2 day old - born healthy and without complications
* 2nd day of life : vomiting, lethargy, hypothermia, feeding poorly, •inc RR, hepatomegaly
* BUN, ÎÎ ammonia , ÎÎargininosuccinic acid both urine and blood
•what enzyme is deficient
ariginosuccinate lyase
97
what enzyme deficiencies can lead to phenylketonuria
* phenylalanine hydroxylase
* tetrahydrobiopterin
* dihydrobiopterin reductase
98
in Maple Syrup Urine Disease, which amino acids could not be metabolize
* valine
* leucine
* isoleucine
LIV
99
which enzyme is deficient in MSUD
α-keto acid dehydrogenase
100
* infant - sweet, smeling urine, vomiting, lethargy, hypoglycemia
* most likely disease condition
branch chain α-ketoacid dehydrogenase deficiency
101
alkaptonuria prevents breaking down 2 amino acids, namely
Tyrosine
and
phenylalanine
102
alkaptonuria results in build-up of ths chemical
homogentisic acid
103
gene involved in alkaptonuria
HGD gene - code for homogentisate oxidase
104
what disease caused deficiency of Porphobilinogen deaminase (hydroxymethylbilane synthase, or uroporphyrinogen I synthase)
acute intermittent porphyria
105
which enzyme:
| •hydrolysis of peptide bonds adjacent to aromatic, branched-chain mino acids, methionine
pepsin
106
All of the following substances are implicated to ÎÎ appetite except
a. orexin
b. NPY
c. AgRP
d. GLP-1
d. GLP-1
107
all substances are implicated to dec appetite except :
a. alpha MSG
b. CART
c. serotonin
d. cannabinoids
d. cannabinoids
108
the major target priority organs that utilize glucose during fasting or starvation are
brain and RBC
109
what does a low carb, moderate fat. high protein diet do ≈ insulin
less than normal insulin response
110
main fuel reserve of the body
adipose tissue triacylglycerol
111
this is the principal site of metabolism of branched chain amino acids
skeletal muscle
112
this system can serve as energy reservoir for for short term demands of muscle metabolism
phosphocreatinine system
113
liver glycogen stores are depleted within ___ of fasting
18-24 hours of fasting
114
All of the ff hormones promote LIPOLYSIS except
a. ACTH
b. GH
c. Vasopressin
d. insulin
insulin
115
in times of starvation, fats can be source of energy at the same time glucose through which of the ff intermediates
a. glycerol
| b. propionyl CoA
116
fasting for 24 hours
principal source of energy
glycogenolysis
117
during last part of 2nd day fsting, what is major source of energy
gluconeogenesis
118
what is the predoinant soruce of energy for the brain after 48 hours of fasting
ketone bodies
119
```
In fasting ≈ phosphorylated /dephosphorylated
•pyruvate dehydrongenase :
•glycogen phosphorylase:
•glycogen synthase:
•acetyl-co carboxylase :
```
* pyruvate dehydrongenase : phosphorylated
* glycogen phosphorylase: phosphorylated
* glycogen synthase: INHIBITED
* acetyl-co carboxylase : phosphorylated
120
* type 1 diabetes patient
* diarrhea x 3 days
* skipped insulin doses due to lack of appetite
* glucose was 400
* urine ketones 1+
•acetyl coa carboxylase is ____
phosphorylated
121
* type 1 diabetes patient
* diarrhea x 3 days
* skipped insulin doses due to lack of appetite
* glucose was 400
* urine ketones 1+
•ketones detected in this patient through urine via the nitroprusside test is predominantly
acetoacetate
122
* type 1 diabetes patient
* diarrhea x 3 days
* skipped insulin doses due to lack of appetite
* glucose was 400
* urine ketones 1+
effect on
•HMG-CoA synthase
•HMG-CoA lyase
* HMG-CoA synthase
* HMG-CoA lyase
both active
123
•patient received insulin infusion
≈ effect on PFK-1
PFK-1 ≈ dephosphorylated
124
•a patient skips dinner everyday, what is expected when she wakse up before bfast
effect on glycogen phosphorylase
glycogen phosphorylase is phosphorylated
125
```
effect of 3 days fasting on
•HMG-CoA reductase
•HMG -coa synthase
•pyruvate carboxylase
•acetyl coa carboxylase
```
* HMG-CoA reductase - phosphorylated
* HMG -coa synthase - activated
* pyruvate carboxylase - stimulated
* acetyl coa carboxylase -phosphorylated
126
hormone least active during 3 days fasting
insulin
127
glucagon effect on glycogen phosphorylase
phosphorylated
128
drinking coffee ≈ effect on glycogen phosphorylase
phosphorylated
129
fatty acid synthesis
| cofactor
biotin
130
VITAMIN B 12 dependent enzymes
* methylmalonyl coa mutase
* leucine aminomutase - converts L leucine to B leucine
* methionine synthase
131
which among the ff does nt need vit b12 for its pathway
a. isoleucine
b. leucine
c. valine
d. methionine
b. leucine
132
vitamin that is considered a hormone
vit D
133
which micronutrient is considered an antioxidant
a. tocopherol
b. magnesium
c. selenium
d. vitamin D
A. tocopherol
134
which vitamin can be synthesized from the body from a specific amino acid
vit b3 (tryptophan)
135
in rxn catalyzed by dopamie B-hydroxylase, what is the cofactor needed
vit C
136
in rxn catalyzed by dopamie B-hydroxylase, what is the product of above rxn
norepinephrine
137
All ÎÎÎ absorption of iron except
a. heme form of iron
b. vit C
c. alcohol
d. NOTA
d. NOTA
138
effects of vit D
* ÎÎ bone resorption
* ÎÎ dietary absorption of phosphate
* dec calcium levels
* dec PTH levels
139
inhibit bone resorption
calcitonin
140
what is the rate limitng enzyme of de novo pyrimidine sythesis
carbamoyl phosphate synthetase II
141
a single turn of human DNA has __ base pairs
10
142
predominant form of DNA in physiologic conditions
B
143
DNA polymerase synthesizes DNA in __ direction
5’ to 3’
144
this enzyme relieve torsional strain produced during DNA unwinding
topoisomerase
145
RNA dependent DNA polymerase that adds DNA to 3’ end of chromosomes to prevent loss of genetic material with every duplication
telomerase
146
the CCA terminal of the tRNA is found in the
acceptor arm
147
which type of RNA comprise majority of cellular RNA , 70%
ribosomal RNA
148
capped by 7-methylguanosine triphosphate group in mRNA functions to
recognition of mRNA in TRANSLATION
149
enzyme involved with synthesizes mRNA
RBA polymerase II
150
RNA product is synthesize in __ direction
5’ to 3’
151
termination of RNA synthesis in BACTERIA is signaled by
rho factor
152
RNA polymerase I catalyzes the transcription of
ribosomal RNA
153
in this mutation, adenine base was mistakenly substituted for a guanine base
G <=> A
transition
154
descriptions of genetic code
degenerate
commaless
universal
155
feature of genetic code stating most AA are coded by multiple codons
degenerate
156
codons UUC and UUU code for phenlyalanine
this displays
degeneracy
157
this feature of genetic code allows translation of the same amino acid despite having a different codon
redundant
158
most AA are coded by multiple codons except for :
a. methionine
b. cysteine
c. alanine
d. valine
a. methionine
159
the tRNA wobble effect leads to which of the ff DNA mutations
silent
160
Duchenne muscular dystrophy is example of which DNA mutation
frameshift
161
method used to detect a specific DNA segment of sequence
a. western blot
b. southern
c. eastern
d. nothern
southern blot
162
substances added to natural gas to make it smell
mercaptan
163
MOA of bolulinum toxin
cleaves SNARE proteins, prevening neurosecretory vesicle fusion
