Biochemistry COPY Flashcards
What is the most common extracellular buffer?
Bicarb
What is the Isoelectric Point?
The pH at which there is no net charge
What is the rate-limiting enzyme of Glycolysis?
PFK-1 (Phosphofructokinase-1)
What is the rate-limiting enzyme in Gluconeogenesis?
Fructose - 1,6 Bisphophatase
What is the rate-limiting enzyme in the HMP shunt?
Glucose-6-Phosphate Dehydrogenase (G-6PD)
What is the rate-limiting enzyme in Glycogenesis?
Glycogen Synthase. Occurs in the Cytoplasm of Liver and muscle
What is the rate-limiting enzyme in Glycogenolysis?
Glycogen Phosphorylase. Occurs in the Cytoplasm of Liver and Muscle
What is the rate-limiting enzyme in FA synthesis?
Acetyl-CoA Carboxylase (ACC)
What is the rate-limiting enzyme in Beta Oxidation?
Carnitine Acyltransferase -1 (CAT-1)
What is the rate-limiting enzyme in Cholesterol syntesis?
HMG CoA Reductase
What is the rate-limiting enzyme in Ketogenesis?
HMG CoA Synthase
What is the rate-limiting enzyme in Purine synthesis?
Glutamine - PRPP
What is the rate-limiting enzyme in Pyrimidine synthesis?
Carbamoyl Phosphate Synthetase-2 (CPS-2)
What is the rate-limiting enzyme in TCA Cycle?
Isocitrate dehydrogenase
What is the rate-limiting enzyme in Urea cycle?
Carbamoyl Phosphate Synthetase-1 (CPS-1)
What is the rate-limiting enzyme in Heme synthesis?
Delta-ALA Synthase
What are the catabolic pathways that create energy? (Occur in the Mitochondria)
Acetyl-CoA production, Beta-oxidation, citric acid cycle, Ketogenesis, Oxidative phosphorylation
What are the anabolic pathways that store energy? (occur in the cytoplasm)
Fatty acid synthesis,
Glycolysis,
HMP shunt,
translation
What are the anabolic & catabolic pathways? (Occurs in both Cytoplasm and Mitochondria)
“HUG”
Heme synthesis
Urea cycle
Gluconeogenesis
What does an Isomerase do?
Creates and isomer
What does an epimerase do?
Creates an epimer, which differs around one chiral carbon
What does a mutase do?
Relocates a functional group within a moleculre (intrachain)
What does a Transferase do?
Relocates a functional group from one molecule to another
What does a Kinase do?
Adds Phosphate group to substrate using ATP
What does a Phosphorylase do?
Adds inorganic Phosphate to substrate, No ATP used
What does a Carboxylase do?
Transfers CO2 groups with the help of Biotin
What does a Synthase do?
Consumes two substrates
What does a Synthetase do?
Consumes two substrates, uses ATP
What does a Phosphatase do?
Removes Phosphate from substrate
What does a Hydroxylase do?
Adds-OH group onto substrate
What does a Lyase do?
Cuts C-C bonds w/ ATP
What does a Dehydrogenase do?
Catalyzes Oxidation-Reduction reactions (gaining or losing an electron)
What does a Thio do?
Breaks S bonds
What is Diffusion?
From high to low concentration No ATP
What is Active Transport?
Goes against concentration gradient
Requires ATP
What is Zero-order kinetics?
Metabolism independent of concentration (rate of elimination is constant)
What is 1st-order kinetics?
Constant drug percentage metabolism over time depends on drug concentration (rate of elimination is directly proportional to drug concentration)
What is Efficacy?
Maximal effect drug can produce regardless of dose (lower w/ non-competitive antagonist)
What effects Efficacy?
Vmax
What is Potency?
Amount of drug needed to produce effect (lower w/ comp antagonist)
What affects Potency?
Km (EC50)
What is Kd?
Concentration of drug that binds 50% of receptors
What is EC50?
Concentration of drug that produces 50% of maximal response
What is Competitive Inhibition?
Fights for active site, no change in Vmax, potency decreases
What is Non-competitive Inhibition?
Binds a regulatory site, no change in Km, Efficacy decreases, decreased Vmax
What is the Peak level?
4 hours after dose (too high - decrease dose)
What is the Trough level?
2 hours before next dose (too high - give less often)
What is t1/2?
Half-life, the time it takes the body to use half of the drug ingested
What is von Gierke?
GLYCOGEN STORAGE DISEASE
G-6 Phosphatase deficiency
severe fasting Hypoglycemia
hepatomegaly/renomegaly (increased glycogen in liver and kidneys)
increased lactase and uric acid levels (=>Gout)
What is Pompe’s?
GLYCOGEN STORAGE DISEASE Lysosomal a-1, 4-glucosidase deficiency Die early/young due to heart failure "Pompe trashes the Pump" (heart, liver, muscle) exercise intolerance
What is Cori’s?
GLYCOGEN STORAGE DISEASE
Debranching, a-1,6 glucosidase enzyme deficiency
short branches of glycogen
milder form than Von Gierke with normal lactate levels
limit-dextrin’s accumulate
What is Anderson’s?
Branching enzyme deficiency,
long chains of glycogen
What is McArdle’s?
GLYCOGEN STORAGE DISEASE
Myophosphorylase deficiency (skeletal muscle Glycogen Phosphorylase)
Increased glycogen in muscle, but muscle cannot break it down
=> painful muscle cramps,
=> myoglobinuria (red urine with strenuous exercise)
And arrhythmia from electrolyte abnormalities
**Second-wind phenomenon (b/c increased muscular blood flow, tired athlete will find renewed energy to exercise harder)
What is Essential Fructosuria?
Fructokinase deficiency
Excrete fructose in blood/urine (still have hexokinase)
What is Fructosemia?
“Fructose intolerance” (Aldolase B deficiency)
kidney and liver damage
occurs in infants after introduction of fruits, honey, and juices
What does a Galactokinase deficiency cause?
Cataracts
What does Galactosemia cause?
Cataracts, mental retardation, liver damage
What does the Citrate shuttle do?
FA transport out of the mitochondria
What does the Carnitine shuttle do?
FA transport into the mitochondria
What lysosomal diseases have a cherry-red macula?
Tay-sachs, Niemann-Pick
What lysosomal diseases have a Gargoyle face?
Gaucher’s (autosomal recessive; glucocerebroside accumulates in white blood cells of organs-macrophages; characterized by bruising, fatigue, anemia and low blood platelet count, enlarged liver/spleen, all due to deficiency of glucocerebrosidase).
Hurler’s (autosomal recessive; coarsening facial features 3-6months of age-prominent frontal bones, skull elongated, flattened nasal bridge, stop growing by age 2, all due to buildup of glycosaminoglycans due to alpha-L-iduronidase deficiency)
What is Tay-Sachs?
Hexosaminidase A deficiency
Hyperreflexia developmental delay
“onion skin” Lysosomes
What is Sandhoff’s?
Hexosaminidase A/B deficiency
What is Gaucher’s?
Glucocerebrosidase (Beta-Glucosidase) deficiency
wrinkled tissue Macrophage’s
Bone pain
pancytopenia
What is Niemann-Pick?
Sphingomyelinase deficiency
Areflexia
Hepatosplenomegaly
foam cells (Lipid Laden macrophages)
What is Fabry’s
alpha-galactosidase A deficiency attacks baby's kidneys and heart XLR accumulation of Ceramide Trihexoside
What is Krabbe’s?
Galactocerebrosidase deficiency peripheral neuropathy optic atrophy globoid bodies accumulation of Galactocerebroside and Psychosine
What is Metachromatic Leukodystrophy?
Arylsulfatase A defieciency
childhood multiple sclerosis with Ataxia/Dementia
accumulation of Cerebroside Sulfate
What is Hunter’s?
Iduronate Sulfatase deficiency milder form XLR no corneal clouding aggressive behavior Accumulation of Heparin and Dermatan Sulfate
What is Hurler’s?
Alph-L-Iduronidase deficiency worse form Gargoylism Corneal clouding accumulation of Heparin and Dermatan Sulfate
What Is Lesch-Nyhan?
HGPRT deficiency grout neuropathy self-mutilation Dystonia XLR Prange sand crystals in diaper
What do white diaper crystals suggest?
Excess Orotic acid
What does biotin donate methyl groups for?
Carboxylation
What does THF donate methyl groups for?
Nucleotides
What does SAM donated methyl groups for?
All other reactions
What is the difference between Heterochromatin and Euchromatin?
Hererochromatin = tightly coiled darker Transcriptionally inactive Euchromatin = loose (10nm fibers) lighter
What are the Purines?
A, G
What are the Pyrimidines?
C, U, T
What is a silent mutation?
Changes leave the same amino acid
What is a point mutation?
Changes one base
What is a transition?
Changes one purine to another purine
What is a transversion?
Changes one purine to a pyrimidine
What is a frameshift mutation?
Insert or delete any number of bases, not divisible by 3, causes misreading of all downstream nucleotides
What is a missense mutation?
Mistaken amino acid substitution (i.e. SS disease Valine for Glutamic Acid)
What is a nonsense mutation?
Early stop codon
What does a Southern blot detect?
DNA, “Snow, Drop”
What does a Northern blot detect?
RNA, “sNow, dRop”
What does a Western blot detect?
Protein, “snoW, droP”
What does Southwestern blot detect?
DNA-binding Proteins (combines south and western blots)
What are the essential amino acids?
Phynlalanine, Valine, Threonine (PVT) Tryptophan, Isoleucine, Methionine (TIM) Histidine, Arginine, Leucine, Lysine (HALL)
What are the essential fatty acids?
Linolenic, Linoleic
What are the acidic amino acids?
Asp, Glu
What are the basic amino acids?
Lys, Arg, His
What are the sulfur-containing amino acids?
Cys, Met
What are the branched amino acids?
“Can’t LIVe w/o them”, Leu, Ile, Val
What are the aromatic amino acids?
Phe, Tyr, Trp
What is the smallest amino acid?
Gly
What are the ketogenic amino acids?
Lys, Leu
What are the glycogenic & ketogenic amino acids?
“PITT” Phe, Iso, Thr, Trp
What are the glycogenic amino acids?
His, Met, Val
What amino acid turns yellow on Ninhydrin reaction?
Pro
What does Trypsin cut?
Arg, Lys
What does Chymotrypsin cut?
Phe, Tyr, Trp
What does alpha one anti-trypsin do?
Inhibits Elastase
What is PKU?
No Phe -> Tyr (via decreased Tetrahydrobiopterin Cofactor or decreased Phe Hydroxylase) NutraSweet (Aspartame) sensitivity mental retardation pale blond hair blue eyes musty odor
What is Albinism?
No Tyr -> Melanin (via Tyrosinase)
What is Maple Syrup Urine disease?
Defective metabolism of branched aa (Leu, Iso, Val) -> aa leak out, urine smells like Maple syrup/ burnt sugar, defect of branched chain alpha Keto acid Dehydrogenase
What is Homocystinuria?
No Homocysteine -> Cysteine (Cystathionine Synthase Deficiency) or Homocysteine Methyltransferase (Methionine Synthase) Deficiency or decreased Affinity of Cystathionine Synthase for Pyridoxal Phosphate Increased Homocysteine in urin Marfanoid Habitus downward dislocation of lens increased risk stroke/MI
What is Cystinuria?
Defect of AA transporter in PCT and GIm prevents reabsorption of Cysteine, Ornithine, Lysine, Arginine (COLA)
Hexagonal (Cysteine) stones in urine (urinary Cyanide nitroprusside test is Dx)
What is Pellagra?
Niacin (B3) deficiency
Dermatitis, Diarrhea, Dementia, Death
What is Hartnup’s?
No tryptophan-cannot make niacin or seratonin
Presents like Pellagra
Genetic, not nutritional disorder
What causes anterior leg bowing?
Neonatal syphilis
What causes lateral leg bowing?
Rickets
What are the names of the B vitamins?
"The Rich Never Lie about Panning Pyrite Filled Creeks" Vit B1 = Thiamine Vit B2 = Riboflavin Vit B3 = Niacin Vit B4 = Lipoic acid Vit B5 = Pantothenic acid Vit B6 = Pyridoxine Vit B7 = Biotin Vit B9 = Folate Vit B12 = Cobalamin
What does Vit A do?
Night vision, CSF production, PTH cofactor
antioxidants
What does Vit B1 do?
Dehydrogenases
transketolase (PPP)
cofactors
What does Vit B2 do?
FAD cofactor
What does Vit B3 do?
NAD cofactor
What does Vit B4 do?
Glycolysis, no known diseases
What does Vit B5 do?
Part of Acetyl-CoA, no known diseases
What does Vit B6 do?
Transaminase cofactor, myelin integrity
What does Vit B7 do?
Carboxylation (Avidin in egg whites (raw) binds Biotin)
What does Vit B9 do?
Nuclear division (Synthesis of Nitrogenous bases for RNA and DNA)
What does Vit B12 do?
Cofactor for HMT & MMA
What does Vit C do?
Collagen synthesis
antioxidant
helps absorb FE++, necessary for Dopamine & hydroxylase for NE
What does Vit D do?
Mineralization of bones and teeth
What Does Vit E do?
Antioxidant
acts as an tagonist to Vit K in high levels
What does Vit K do?
Clotting
Synthesized by intestinal flora
What does Ca2+ do?
Neuronal function, atrial depolarization, smooth muscle contractility
What does Cu2+ do?
Collagen Synthesis
What does Fe2+ do?
Hb function, electron transport
What is Bronze pigmentation?
Fe deposit in skin
What is Bronze cirrhosis?
Fe deposit in liver
What is Bronze diabetes?
Fe deposit in pancreas
What is Hemosiderosis?
Fe overload in bone marrow
What is Hemochromatosis?
Fe deposit in organs
What does Mg2+ do?
PTH and kinase cofactor
What does Zn2+ do?
Taste buds, hair, sperm function