Metabolism Flashcards
(179 cards)
1
Q
Metabolism that occurs in Mitochondria
A
beta-oxidation for FA oxidation, acetyl-CoA production, TCA cycle, oxudative phosphorylation
2
Q
Metabolism in the Cytoplasm
A
Glycolysis, FA synthesis, HMP shunt, protein syn in rER, steroid syn in sER, cholesterol synthesis
3
Q
Metabolism in both mitochondria and cytoplasm
A
Heme synthesis, Urea cycle, Gluconeogeneis
4
Q
Kinase
A
Uses ATP to add high-energy phosphate group unto substrate
5
Q
Phosphorylase
A
Adds inorganic phosphate onto substrate without using ATP
6
Q
Phosphatase
A
removes phosphate group from substrate
7
Q
Dehydrogenase
A
catalyzes oxidation-reduction reactions
8
Q
Hydroxylase
A
adds hydroxyl group onto substrate
9
Q
Carboxylase
A
Transfers CO2 groups with the help pf biotin
10
Q
Mutase
A
Relocates a functional group within a molecule
ex is vitB12-dependent methylmalonyl-CoA mutase
11
Q
Rate-determining enzyme for Glycolysis
A
Phosphofructokinase
inhibited by ATP and citrate
12
Q
Rate-determining enzyme for Gluconeogenesis
A
Fructose-1,6-Bisphosphatase
inhibited by AMP and F2,6BP
13
Q
Rate-determining enzyme for TCA cycle
A
isocitrate dehydrogenase
inhibited by ATP and NADH
14
Q
Rate-determining enzyme for Glycogenesis
A
Glycogen Synthase
inhibited by epinephrine and glucagon
15
Q
Rate-determining enzyme for Glycogenolysis
A
Glycogen Phosphorylase
inhibited by G6P, insulin and ATP
16
Q
Rate-determining enzyme for HMP shunt
A
G6PD
inhibited by NADPH
17
Q
Rate-determining enzyme for de novo pyrimidine synthesis
A
Carbamoyl phosphate synthetase II or CPSII
18
Q
Rate-determining enzyme for de novo purine synthesis
A
Glutamine-phosphoribosylpyrophosphate (PRPP) amidotransferase
inhibited by AMP, IMP, GMP
19
Q
Rate-determining enzyme for urea cycle
A
Carbamoyl phosphate synthetase I (CPSI)
Activated by N-acetylglutamate
20
Q
Rate-determining enzyme for FA synthesis
A
Carnitine acyltransferase I
inhibited by malonyl-CoA
21
Q
Rate-determining enzyme for Ketogenesis
A
HMG-CoA synthase
22
Q
Rate-determining enzyme for Cholesterol Synthesis
A
HMG-CoA reductase
inhibited by glucagon and cholesterol
activated by insulin and thyroxine
23
Q
Galactokinase
A
galactose → galactose-1-phosphate
24
Q
Galactose-1-phosphate uridyltransferase
A
galactose-1-phosphate → glucose-1-phosphate
25
Hexokinase/Glucokinase
Glucose ↔ Glucose-6-P
26
G6PD
Glucose-6-P→ 6-phosphogluonolactone
HMP shunt
lack of this causes von Gierke's
27
Phosphofructokinase
rate limiting step in glycolysis
makes fructose-6-P → F1,6P
to reverse this you would need F1,6Bisphosphatase which is rate limiting for gluconeogenesis
28
Adolase B
found in liver
| A is in muscle
29
Pyruvate Kinase
PEP to pyruvate
30
Pyruvate dehydrogenase
requires thiamine cofactor TPP
| Pyruvate → acetyl-CoA
31
Pyruvate Carboxylase
Requires Biotin
| Pyruvate → Oxaloacetate
32
Isocitrate Dehydrogenase
Rate limiting step in TCA,
| Isocitrate → alpha-ketoglutarate
33
Ornithine Transcarbamylase
Requires TTP
| alpha-ketoglutarate → succinyl-CoA
34
ATP production in the heart and liver
net 32 ATP, malate-aspartate shittle
35
ATP production in the muscle
net 30 ATP, uses glycerol-3-phosphate shuttle
36
ATP production in Anaerobic Glycolysis
net 2 ATP per glucose molecule
37
Phosphoryl groups
carried by ATP
38
Electrons
carried by NADH, NADPH, FADH2
39
Acyl groups
carried by CoA, lipoamide
40
CO2 carried by
Biotin
41
1 carbon units
carried by tetrahydrofolates
42
CH3 groups
carried by SAM
43
Aldehydes
Carried by TPP
44
Product of HMP Shunt
NADPH
45
Use of NADPH
anabolic processes like steroid and FA synthesis
respiratory burst
cytochrome P450 system
glutathione reductase
46
Low Km
High affinity
47
Low Vmax
Low capacity
48
Glucokinase
induced by insulin, high Km, found in liver and beta-cells of pancreas
49
Mutated in MODY
Glucokinase
50
hexokinase
Low Km, Low Vmax, in most tissues except liver and beta cells of pancreas
inhibited by glucose-6-P
51
Enzymes that require ATP in glycolysis
hexokinase/glucokinase
| phosphofructokinase-1
52
Enzymes that produce ATP in glycolysis
Phosphoglycerate kinase
| Pyruvate Kinase
53
Purely ketogenic amino acids
Lysine and Leucine
54
Pyruvate dehydroxylase complex deficiency
causes a build up or pyruvate that gets shunted to lactate via LDH and alanine via ALT
neuro issues, lactic acidosis, increased serum alanine in infancy
55
Tx for Pyruvate dehydroxylase complex deficiency
increase ketogenic nutrients, high fat content of increase lysine and leucine
56
Complex I of ETC
uses NADH electrons and pumps out hydrogen into intermembrane space of mitochondria
inhibited by Rotenone
57
Complex II of ETC
uses FADH2 electons
| succinate dehydroxynase
58
Complex III of ETC
take electrons from CoQ and pumps hydrogen into intermembrane space
inhibited by Antimycin A
59
Complex IV
takes electrons from cytochrome C, makes water
pumps hydrogen into the intermembrane space
inhibited by cyanide and CO
60
ATP synthase
makes ATP and pushes H into mitochondria matrix
| inhibited by Oligomycin
61
Uncoupling Agents
2,4-Dinitophenol, aspirin, thermogenin in brown fat
increases permeability of mitochondrial membrane
decreases hydrogen gradient and increases oxygen consumption
products heat
62
Glucose-6-phosphatase
occurs in ER to make glucose
| an irreversible enzyme
63
Odd-chain FA
yield 1 propionyl-CoA during metabolism, which can enter the TCA cycle as succinyl CoA
can also undergo gluconeogenesis
64
Even-chain FA
can't produce glucose, only yield acetyl-CoA
65
Purpose of HMP Shunt
provides a source of NADPH which is required to reduce glutathione inside RBCs to prevent destruction and for FA and cholesterol biosynthesis
66
Sites of HMP Shunt
Lactating mammary glands, adrenal cortex for steroid syn, RBCs
67
Oxidative HMP shunt Enzyme
Glucose-6-dehydrogenase, rate limiting step the make G6P into 2NADPH, CO2, and ribulose-5-P
68
Nonoxidative HMP shunt enzyme
phosphopentose isomerase, transketolase (req B1)
| makes ribulose5P into ribose5Pi, G3P and F6P
69
NADPH oxidase deficiency
chronic granulomatous disease
70
Steps of Oxidative Respiratory Burst
NADPH oxidase, Superoxide dismutase, myeloperoxidase, glutathione peroxidase (req selenium), glutathione reductase (req selenium), G6PD
71
Pyocyanin
P. aeruginosa tonxin that generates ROS to kill competing microbes
72
Lactoferrin
protein in secretory fluid and neutrophils that inhibits microbial growth viw iron chelation
73
Heinz Bodies
G6PD deficiency, precipitated and oxidized Hb
74
Bite Cells
G6PD deficiency,phagocytic removal of Heiz bodies by splenic macrophages
75
Agents that exacerbate G6PD deficiency
fava beans, sulfonamides, primaquine, antiTB drugs
| they are oxidizing agents that lead to hemolytic anemia
76
G6PD deficiency genetics
X-linked recessive, most common human enzyme deficiency
| primarily in blacks
77
Defect in fructokinase
Essential fructosuria
| auto recessive, see fructose in blood and urine otherwise fairly benign
78
Hereditary deficiency in aldolase B
Fructose Intolerance - stay away from honey, juice and fruit
Autosomal recessive
Fructose-1-P accumulates
hypoglycemia, jaundice, cirrhosis, vomiting
79
infantile cataracts, failure to track objects, don't develop a social smile
Galactokinase deficiency
galactitol accumulates
auto recessive
80
Classic Galactosemia
absence of galactose-1P uridyltransferase
galactitol accumulates in lens of eye
failure to thrive, jaundice, hepatomegaly, infantile cataracts, intellectual disability
81
E. coli sepsis
classic galactosemia can lead to neonatal E. coli sepsis
82
Areas with aldose reductase
Schwann cells, retina, kidneys
| need NADPH to make slucose into sorbitol
83
Osmotic Diarrhea
Lactase deficiency
| also gets bloating cramosm and flatulancea
84
Glucogenic Amino Acids
methionine, Valine, Histidine
85
Acidic Amino Acids
aspartic acid, glutamic acid
| negatively charged at body's pH
86
Basic Amino Acids
arginine, lysine, histidine
| has no charge at body's pH
87
Amino acids required during periods of growth
arginine and histidine
88
Amino Acids increased in histones which bind negatively charged DNA
Arginine and lysine
89
Ornithine Transcarbamylase
ornithine into citrulline
| requires carbamoyl phsophatase
90
Arginase
makes arginine and H2O into urea to be excreted by kidneys
91
Amino Acids that transport ammonia
Alanine and Glutamate
92
Ammonia intoxication
tremor (asterixis), slurred speech, somnolence, vomiting, cerebral edeam and blurred vision
93
Too much ammonia inhibits
TCA cycle
94
Traps NH4+ in GI tract for excretion
Lactulose, used to tx hyperammonemia
95
Binds to amino acids in diet for excretion
Benzoate or Phenylbutyrate (tx hyperammonemia)
96
Required cofactor for carbamoyl phosphate synthetase I
N-acetylglutamate
97
N-acetylglutamate Deficiency
hyperammonemia (tremor, slurred speech, cerebral edema)
| increased ornithine with normal urea cycle enzymes
98
increase orotic acid in blood and urine
Ornithine Transcarbamylase Deficiency
X-linked recessive, excess ammonia
tremor, slurred speech, cerebral edema
orotic acid is part of pyrimidine pathway
99
Use of SAM
NE → Epinephrine
100
makes melatonin
Tryptophan→ serotonin → melatonin
101
Amino acid for porphyrin/heme
Glycine
102
Amino Acid for GABA and Glutathione
Glutamate
103
Amino Acid for Creatine, Urea, Nitric Oxide
Arginine
104
Deficient in Phenylalanine hydroxylase
PKU
105
Deficient in Homogentisate oxidase
Alkaptonuria
| degradative pathway of tyrosine to fumarate
106
Deficient in Tyrosinase
Albinism
107
Inhibited by Carbidopa
DOPA decarboxylase to inhibit DA production
108
musty body odor, fair skin, eczema
PKU (Auto recessive)
109
Avoid aspartame
PKU because it contains phenylalanin
110
Brown pigmented sclera, urine turns black on prolonged exposure to air
Alkaptonuria (ochronosis)
111
Cystathionine Synthase deficiency
Homocystinuria
112
Tx of Homocystinuria from cystathione synthase deficiency
decrease methionine, increase cysteine, increase B12 and folate in diet
113
Decreased affinity of cystathionine synthase for pyridoxal phosphate
Homocystinuria, tx with increase Vit B6 and cysteine
114
Homocysteine methyltransferase deficiency
Homocystinuria, tx with increase methionine in diet
115
Findings for homocystinuria
increase homocysteine in urine, dumb, osteoporosis, tall stature, kyphosis, lens subluxation (down and in), thrombosis, and atherosclerosis
116
Hexagonal Cystine Stones
Cystinuria
| Tx K-citrate and acetazolamide
117
Urinary cyanide-nitroprusside test
Diagnostic for Cystinuria
118
Hereditary defect in Cystinuria
Auto recessive
| renal PCT and intestinal AA transporter for Cysteine, Ornithine, Lysine and Arginine (COLA)
119
Branched Amino Acids
Maple Syrup Urine Disease
I Love Vermont Maple Syrup
Isoleucine, leucine and valine
120
Limit Dextran
1-4 residues remaining on a branch after glycogen phosphorylase has already shortened it
121
Von Gierke Disease
deficient in glucose-6-phosphatase, aut recessive
| severe fasting hypoglycemia, increased blood lactate, increased glycogen in liver
122
Tx of Von Gierke Dx
frequent oral glucose/cornstarch
| AVOID fructose and galactose
123
Cardiomyopathy early death glycogen storage dx
Pompe Disease, deficient in lysosomal alpha1,4-glucosidase
124
Cori Disease
Lack debranching enzyme alpha-1,6-glucosidase
| fasting hypoglycemia
125
McArdle Disease
deficient in myophosphorylase, increase glycogen in muscle
problem with beginning of exercise
red urine with strenuous exerise
126
Muscle Carnitine Deficiency
muscle pain later with exercise because fatty acid oxidation is used AFTER glycogen for muscle energy
FA in muscle biopsy
127
deficient in alpha-galactosidase A
Fabry Disease X-linked recessive
128
Accum ceramide trihexoside
Fabry Disease
129
peripheral neuropathy of hands/feet, angiokeratomas, CV/renal disease
Fabry Disease X-linked recessive
130
crumpled tissue paper
Gaucher Disease, auto recessive
131
Accum Glucocerebroside
Gaucher Disease, auto recessive
132
Deficient in Glucocerebrosidase of beta-glucosidase
Gaucher Disease, auto recessive
133
Cherry-red spot on macula, foam cells
Niemann-Pick Disease, Auto recessive
134
Cherry-red spot on macula, lysosomes with onion skin
Tay-Sachs, Auto recessive
135
Deficient in Sphingomyelinase thus accumulate sphingomyelin
Niemann-Pick Disease, Auto recessive
| hepatosplenomegaly, progressive neurodegen
136
Deficient in Hexosaminidase A and accumulates GM2 ganglioside
Tay-Sachs, Auto recessive
| Progressive neurodegeneration
137
Globoid Cells
Krabbe Disease, Autosomal Recessive
138
Deficient in Galactocerebrosidase
Krabbe Disease, Autosomal Recessive
| developmental delay, optic atrophy, periph neuropathy
139
Deficient in Arylsulfatase A
Metachromatic Leukodystrophy, autosomal recessive
| accum cerebroside sulfate
140
Central and peripheral demyelination with ataxia and dementia
Metachromatic Leukodystrophy, autosomal recessive
| accum cerebroside sulfate
141
Deficient in alpha-L-iduronidase
Autosomal recessive Hurler Disease
142
corneal clouding, gargoylism, airway obstruction, mucopolysaccharidoses
Autosomal recessive Hurler Disease
143
Deficiency in Iduronate sulfatase
Hunter Syndrome - X-linked recessive
| No corneal clouding, aggressive behavior
144
Hypoketotic Hypoglycemia
Carnitine deficiency
| inability to transfer LCFAs into the mitochondria
145
Ketone Bodies
Prolonged Starvation and Diabetic Ketoacidosis
| Oxaloacetate is depleted for gluconeogenesis
146
Protein and Carbohydrates
4 kcal
147
Fat
9 kcal
148
Alcohol
7 kcal
149
Fed State (after a meal)
glycolysis and aerobic respiration
| insulin stim storage of lipids, proteins and glycogen
150
Fasting (between meals)
glucagon, adrenaline stimulates use of fuel reserves
hepatic glycogenolysis(major)
FFA release from fat (minor)
151
Starvation (1-3days)
Blood glucose maintained by hepatic glycogenolysis, FFA from adipose, muscle and liver shift fuel from glucose to FFA
152
Glycogen Stores Depleted
After 1 day of starvation
153
Starvation (>3days)
Ketones major source of fuel for brain
154
Lecithin-cholesterol acyltransferase LCAT
esterfies 2/3 of palsma cholesterol
155
S/E of statins
Rhabdomyolysis and Hepatotoxicity
| must check LFTs and Creatine Kinase levels
156
Pancreatic Lipase
degradation of dietary TGs in small intestine
157
Lipoprotein Lipase
degradation of TG circulating in chlyomicrons and VLDLs
| found on vascular endothelial surface
158
Hepatic TG Lipase
degrades TG remaining on IDL
159
Hormone sensitive Lipaase
degrades TG stored in Adipocytes
160
ApoE
mediated remnant uptake
| found on chylomicron, its remnant, VLDL, IDL and HDL
161
ApoA-I
Activates LCAT
| on chylomicron and HDL
162
ApoC-II
LPL Cofactor
| on chlymicron, VLDL and HDL
163
ApoB-48
Mediates Chylomicron Secretion
| On chylomicron remnant and on Chylomircon
164
ApoB-100
Binds LDL-receptor
| on VLDL, IDL, LDL
165
Transports cholesterol from liver to tissues
LDL
166
Transports cholesterol from periphery to liver
HDL
167
Composition of Lipoproteins
cholesterol, TGs, phospholipids
168
Fx of Chylomicron
Delivers dietary TG to peripheral tissue.
| Delivers cholesterol to liver in form of chylomicron remnants
169
Fx of IDL
degraded VLDL, delivers TGs and cholesterol to liver
170
Fx of VLDL
delivers hepatic TGs to peripheral tissue, secreted by liver
171
Fx of HDL
acts as repository for apoC and ApeE which are needed for chylomicron and VLDL metabolism
alcohol increases synthesis, secreted from both liver and intestine
172
Increased Chyomicrons, TG and cholesterol in blood
Hyper-chylomicronemia
| Autosomal recessive
173
LPL deficiency fo altered apoC-II, get eruptive/pruritic xanthomas
Hyper-chylomicronemia
| Autosomal recessive
174
Increased LDL and cholesterol in blood
Type IIa, Autosomal Dominant
| Familial Hypercholesterolemia
175
Absent fo defective LDL receptors
Type IIa, Autosomal Dominant
| Familial Hypercholesterolemia
176
Accelerated atherosclerosis, Achilles xanthomas and corneal arcus
Type IIa, Autosomal Dominant
| Familial Hypercholesterolemia
177
Increase VLDL and TG in blood
Type IV, Autosomal Dominant
| Hyper-triglyceridemia
178
Overproduction of VLDL
Type IV, Autosomal Dominant
| Hyper-triglyceridemia
179
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