Biochem-Metabolism Flashcards
1
Q
Mitochondria as metabolism site:
A
Fatty acid oxidation (B-oxidation), acteyl-coA production, TCA cycle, ketogenesis, oxidative phosphorylation (FAT KOP thought he was MITO)
2
Q
Cytoplasm as metabolism site:
A
HMP shunt, glycolysis, steroid synthesis, protein synthesis, cholesterol synthesis
3
Q
Both cytoplasm and mitochondria for metabolism?
A
Heme synthesis, Urea cycle, Gluconeogenesis (HUGs take two (i.e. both))
4
Q
Process: Glycolysis
Rate limiting enzyme?
Regulators + and -
A
Phosphofructokinase-1 (PFK-1)
+AMP, fructose 2,6-biphosphate
-ATP, citrate
5
Q
Process: Gluconeogenesis
Rate limiting enzyme?
Regulators + and -
A
Frustose-1,6,-bisphosphatase
+ ATP, acetyl-coA
-AMP, fructose 2,6-bisphosphate
6
Q
Process: TCA cycle
Rate limiting enzyme
Regulators + and -
A
Isocitrate dehydrogenase
+ ADP
- ATP, NADH
7
Q
Process: Glycogenesis
Rate limiting enzyme?
+ and - regulators
A
Glycogen synthase
+ Glucose-6-phosphate, insulin, cortisol
- Epinephrine, glucagon
8
Q
Process: Glycogenolysis
Rate limiting enzyme?
+ and - regulators
A
Glycogen phosphorylase
+ Epinephrine, glucagon, AMP
-Glucose-6-phosphate, insulin, ATP
9
Q
HMP shunt
Rate limiting enzyme
+ and - regulators
A
Glucose-6-phosphate dehydrogenase (G6PD)
+ NADP+
- NADPH
10
Q
De novo pyrimidine synthesis
Rate limiting enzyme
+ and - regulator
A
CPS II
+ATP
-UTP
11
Q
De novo purine synthesis
Rate limiting enzyme
+ and - regulator
A
Glutamine-PRPP-amidotransferase
-AMP, IMP, GMP
12
Q
Urea cycle
Rate limiting enzyme
+ and - regulator
A
Carbomoyl phosphate synthetase I
+ N-acetylglutamate
13
Q
Fatty acid synthesis
Rate limiting enzyme
+ and - regulator
A
Acetyl-CoA carboxylase
+ insulin, citrate
- glucagon, palmitoyl-CoA
14
Q
Fatty acid oxidation
Rate limiting enzyme
+ and - regulator
A
Carnitine acyltrnasferase I
- malonyl-coA
15
Q
Ketogenesis
Rate limiting enzyme
+ and - regulator
A
HMG-CoA synthase
16
Q
Cholesterol synthesis
Rate limiting enzyme
+ and - regulator
A
+ Insulin, thyroxine
- glucagon, cholesterol
17
Q
What monosaccharide is metabolized the fastest and why?
A
Fructose because it enters glycolysis after PFK-1 (a potent regulator of glycolysis)
18
Q
What toxin causes glycolysis to produce zero net ATP?
A
Arsenic
19
Q
Aerobic metabolism in heart/liver ATP production
A
32 ATP via malate/aspartate shuttle
20
Q
Anaerobic metabolism in muscle ATP production
A
30 ATP via glycerol 3 phosphate shuttel
21
Q
Universal electron acceptors?
A
NAD+, NADP+, FAD+
22
Q
NAD+ is generally used in _____
A
Catabolic processes carry reducing equivalents away as NADH
23
Q
NADPH generally used in?
What is it a producut of?
A
- Anabolic processes, respiratory burst, cyp450, glutathione reductase
- HMP shunt
24
Q
Negative feedback on glucokinase production?
A
Fructose-6-phosphate
25
Negative feedback on hexokinase production?
Glucose-6-phosphate
26
Garlic breath, vomiting, rice-water stools
Arsenic poisoning
27
PDH complex and alphaketoglutarate dehydrogenase complex require what 5 same cofactors?
pyrophosphate (B1, thimaine;Tpp), Lipoic acid, CoA (B5, pantothenic acid), NAD (B3, niacin), FAD (B2, riboflavin)-->Tender Loving Care For Nobody
28
PDH complex is activated by exercise and how is it acvitvated?
Increase NAD+/NADH, Increase Calcium, Increase ADP
29
High Fructose 2,6 BP has what affect on alanine?
Prevents conversion of pyruvate to alanine in muscle and transport over to liver where it is converted back to pyruvate for use in gluconeogenesis (i.e. gluconeogenic conversion of alanine to glucose)
30
Only purely ketogenic amino acids
Lysine and leucine
31
Treatment of PDH complex deficiency and why?
Increase intake of ketogenic nutrients because they do not lead to formation of increase lactic acid and subsequently do not increase blood lactate levels
32
Fate of pyruvate generated during glycolysis is dependent on presence of oxygen. What happens with adequate or inadequate O2?
Adequate O2: Pyruvate-->Acetyl CoA
| Inadequate O2: Pyruvate-->Lactate (increase lactate-->metabolic acidosis with compensatory respiratory alkalosis)
33
pyruvate to acetyl coA produces what?
1 NADH, 1 CO2
34
Function of ALT and cofactor
Alanine aminotransferase (B6): alanine carriers amino groups to liver from muscle
35
Function of PC and cofactor
Pyruvate carboxylase (biotin): oxaloacetate can replenish TCA cycle or be used in gluconeogenesis
36
function of Pyruvate dehdyrogenase and cofactor
(B1, B2, B3, B5, lipoic acid): transition from glycolysis to TCA cycle
37
Function of lactic acid dehydrogenase and cofactor
(B3): end of anaerobic glycolysis-->major pathway in RBC, WBC, cornea, lens, testes, kidney medulla
38
Function of lipoic acid
Serves in decarboxylation of alpha ketoacids and transfer of alkyl groups (ie. from pyruvate to coenzyme A)
39
Oxaloacetate-->Citrate
Citrate synthase
40
Isocitrate-->alphaketogluctarate
Isocitrate dehydrogenase
41
Alphaketoglutarate-->succinyl-coA
alpha ketoglutarate dehydrogenase.
42
Krebs pneumonic and what it generates for each acetyl coA
3 NADH, 1 FADH2, 2 CO2, 1 GTP "Citrate Is Krebs Starting Substrate For Making Oxaloacetate"
43
Complex 4
cytochrome c oxidsase
44
Complex 3
Coenzyme q
45
Complex 2
succinate dehydrogeniase
46
Block complex I
Rotenone
47
Bock complex III (coenzyme q)
Antimycin A
48
Block complex IV (cytochrome c oxidase)
Cyanide, CO
49
Block complex V (ATP synthase)
Oligomycin
50
Uncoupling agents
2,4 dinitrophenol, aspirin, thermogenin in brown fat (produces heat)
51
Glucocorticoids are potent stimulators of gluconeogenesis and specifically increase what two enzymes
Phosphoenol pyruvate carboxykinase and glucose 6 phosphatase
52
Difference between odd chain fatty acids and even chain fatty acids in glucose source?
Odd chain fatty acids can be converted to propionyl CoA during metabolism, which can enter the TCA cycle (as succinyl-coA) and undergo gluconeogenesis, and serve as glucose source
Even chain fatty acids cannoot produce new glucose, since they yield only acetyl-CoA equivalents.
53
Predominant source of carbon atoms for glucose synthesis during gluconeogenesis?
Lactate
54
What is pyruvate derived from in gluconeogenesis?
Lactate, glycerol, glucogenic AA (eg. alanine)
55
HMP shunt main job
Provide NADPH
56
Oxidative HMP shunt pathway
Glucose 6-phosphate-->Ribulose 5 phosphate, 2 NADPH, CO2 via Glucose 6 phosphate dehydrogenase
57
Non-oxidative HMP shunt pathway
Ribulose5-PhosphateRibose 5 phosphate, Glyceraldehyde 3 phosphate, Fructose 6 phosphate via transketolases and phosphopentose isomerase
58
Oxidizing agents that can percipitate G6PD deficiency?
"Spleen Purges Nasty Inclusions From Damaged Cells"->Sulfonamides, Primaquine, Nitrofurantoin, Isoniazid, Fava Beans, Dapsone, Chloroquine
59
With fructokinase deficiency, what is primary method of metabolism of fructose to fructose 6-phosphate?
Hexokinase
60
Urine dipstick tests for what sugar in blood?
Glucose only!!
61
Why do symptoms arise in fructose intolerance?
fructose 1-p is trapped and usage of all fructose prevents glycogenolysis and gluconeogenesis causing hypoglycemia. Also see jaundice, cirrhosis (hepatocellular manifestations)
62
Alcohol counterpart of glucose?
Sorbitol (converted from glucose via aldose reductose)
63
Tissues with aldose reductase and sorbitol dehydrogenase
Liver, ovaries, seminal vesicles, very low levels of sorbitol dehydrogense in lens
64
Tissues with aldose reductase only
Schwann cells, kidney, retina
65
Essential amino acids (need to be supplied in diet)
"PVT TIM HALL" Phenylalanine, Valine, Threonine, Tryoptophan,, Isoleucine, Methionine, Histidine, Arginine (considered essential for children because needed during periods of growth), Lysine, Leucine
66
Acidic AA (negatively charged at body pH)
Aspartic acid (ie. aspartate) , glutamic acid (ie glutamate)
67
Basic AA
Arginine (most basic), Lysine, Histidine
68
pH>pKa
protons dissociate from amino acids
69
pH
proton associate to group on amino acids
70
Lactase deficiency stool and breath tests?
decrease pH stool and increase hydrogen content in breath
71
Two AA required during periods of growth
Arginine and histidine
72
Urea's nitrogen is derived from what?
Aspartate and NH3
73
Urea cycle pneumonic
Ordinarily, Careless Crappers Are Also Frivilous About Urination
74
Two major carriers of nitrogen from tissues?
Alanine and glutamine
75
Acidify GI tract and trap NH4+ for excretion
Lactulose
76
Decrease colonic ammoniagenic bacteria
Rifaximin
77
(Both of these bind AA and lead to excretion) may be given to decrease ammonia levels
Benzoate or Phenylbutyrate
78
Ornithine transcarbamylase deficiency
X-linked recessive (vs other urea cycle deficiencies, that are auto recessive)
79
Cofactor used in hydroxylase enzymes in synthesis of tyrosine, DOPA, serotonin, NO
BH4
80
Phenylalanine and derivatives
Phe-->Tyrosine (converted to thyroxine)-->DOPA (which is converted to melanin)-->Dopamine-->Epi-->NE
81
Tryptophan and derivatives
Serotonin, Niacin
82
Histidine and derivative
Histamine
83
Glutamate and derivitives
GABA and Glutathione
84
Glycine and deriviatives
Porphyrin-->Heme
85
Arginine and derivitives
NO, Urea, Creatinine
86
PKU mutated enzyme
Phenylalanine hydroxylase
87
MSUD mutated enzyme
alphaketoacid dehydrogenase
88
Mutated enzyme albinism
tyrosinase
89
mutated enzyme alkaptonuria
Homogentisate oxidase
90
NE and dopamine is produced by _____, while epinephrine is only produced by _______
CNS and ANS, adrenal gland
91
First step in catecholamine synthesis in adrenal medulla:
Tyrosine-->DOPA via tyrosine hydroxylase
92
Failure to absorb what AA in cystinuria
Cysteine, ornithine, lysine, arginine (COLA)
93
alpha 1,4 glycosidic linkage to glycogen chain is broken down to?
Glucose 1-P via glycogen phosphorylase
94
alpha 1,6 glycosidic linkage is borken down to?
glucose via alpha 1,6 glucosidase
95
Glycogen-->Glucose 1-Phosphate
Glycogen phosphorylase
96
Glucose 1-Phosphate-->Glucose 6-phosphate
Phosphoglucomutase
97
Glucose 6-Phosphate-->Glucose
Glucose 6-phosphatase (only in liver)
98
alpha 1,6 glucosidase function?
alpha 1,6 glycosidic linkage -->glucose
99
Von Gierke deficiency+treatment
Pompe deficiency
Cori dificiency
McArdle deficiency
Glucose-6-Phosphatase, glucose/cornstarch at night; avoidance of fructose+galactose
Lysosomal alpha 1,4 glucosidase (acid maltase)
Debranching enzyme (alpha 1,6-glucosidase)
Skeletal muscle Glycogen phosphorylase (myophosphorylase), Treat w/ vitamin B6 (cofactor)
100
Fabry disease
Symptoms
Deficient enzyme?
Accumulated substrate?
Symptoms: Peripheral neuropathy of hands/feet, angiokeratomas, cardiovascular/renal disease
alpha-galactosidase A
Ceramide trihexoside
101
Gaucher disease
Symptoms
Deficient enzyme?
Accumulated substrate?
Symptoms: Hepatosplenomegaly, pancytopenia, osteoporosis, aseptic necrosis of femur, bone crises, Gaucher cells,
Glucocerebrosidase (B-glucosidase)
Glucocerebroside
102
Niemann-Pick
Symptoms
Deficient enzyme?
Accumulated substrate?
Progressive neurodegeneration, hepatosplenomegaly, foam cells (lipid-laden macrophages), "cherry-red" spot on macula
Sphingomyelinase
Sphingomyelin
103
Tay-sachs disease
Symptoms
Deficient enzyme
accumulated substrate
Progressive neurodegneration, no hepatosplenomegaly, developmental delay, "cherry-red" spot on macula, lysososmes with onion skin
B-hexosaminidase A
GM2 ganglioside
104
Krabbe disease
Symptoms
Deficient enzyme
accumulated substrate
Peripheral neuropathy, developmental delay, optic atrophy, globoid cells
Galactocerebrosidase
Galactocerebroside
Psychosine
105
Metachromatic leukodystrophy
Symptoms
Deficient enzyme
Accumulated substrate
Central and peripheral demyelination with ataxia, dementia
Arylsulfatase A
Cerebroside sulfate
106
Hurler syndrome
Symptoms
Deficient enzyme
Accumulated substrate
Developmental delay, gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly
Alpha-l-iduronidase
Heparan sulfate, dermatan sulfate
107
Hunter syndrome
Symptoms
Deficient enzyme
accumulated substrate
Mild hurler +aggressive behavior, NO corneal clouding
Iduronate sulfatase
Heparan sulfate, dermatan sulfate
108
Rate limiting enzyme in fatty acid synthesis
acetyl coA carboxylase
109
Rate limiting enzyme in LCFA degradation
Carnitine acyltransferase I
110
Predominant location of fatty acid synthesis
liver, lactating mammary glands, adipose tissue
111
What is the difference in odd chain fatty acid and even chain fatty acid production?
Odd chain fatty acids yield 1 propionyl coA which enter TCA cycle as succinyl coA, undergo gluconeogenesis and serve as glucose source
Even chain fatty acids cannot produce new glucose, since they yield only acetyl-coA equivalents
112
What is the only TAG component from odd chain FFA that contributes to gluconeogenesis?
propionyl-coA
113
Only organ that can use glycerol for energy
liver
114
Type I hyperchylomicronemia deficiency
lipoprotein lipase deficiency or altered apolipoprotein CII
115
Type IIa familial hypercholesterolemia deficiency
LDL receptor deficiency
116
Type IV hypertriglyceridemia deficiency
Hepatic overproduction of VLDL
