Biochemistry 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