Biochem Flashcards
What is the most common intracellular buffer?
Protein
What is the most common extracellular buffer?
Bicarbonate
What is a Zwitterion?
A molecule with one negative and one positive end
What is the isoelectric point?
The pH at which there is not net charge
What is the rare limiting enzyme in Glycolisis?
PFK-1 (phospho fructokinase 1)
What is the rate limiting enzyme in Gluconeogenesis?
Pyruvate carboxylase
What is the rate limiting enzyme in the HMP shunt?
G-6PD (Glucose - 6 -phosphate dehydrogenase)
What is the rate limiting enzyme in Glycogenesis?
Glycogen synthase
What is the rate limiting enzyme in Glycogenolysis?
Glycogen phosphorylase
What is the rate limiting enzyme in Fatty Acid synthesis?
AcCoA carboxylase
What is the rate limiting enzyme in B-oxidation?
CAT-1
What is the rate limiting enzyme in cholesterol synthesis?
HMG CoA reductase
What is the rate limiting enzyme in Ketogenosis?
HMG CoA synthase
What is the rate limiting enzyme in Purine synthesis?
PRPP synthase
What is the rate limiting enzyme in Pyrimidine synthesis?
Asp transcarbamoylase
What is the rate limiting enzyme in TCA cycle?
Isocitrate dehydrogenase
What is the rate limiting enzyme in the urea cycle?
CPS I
What is the rate limiting enzyme in heme synthesis?
delta-ALA-synthase
What are the catabolic pathways that create energy?
“ABC”
Acetyl-CoA production
b-oxidation
citric acid cycle
What are the anabolic pathways that store energy?
"EFGH" ER Fatty Acid synthesis Glycolysis HMP shunt
What are the anabolic + catabolic pathways?
“HUG”
Heme synthesis
Urea cycle
Gluconeogenesis
What does an isomerase do?
creates an isomer
What does an epimerase do?
Creates an epimer, which differs around 1 chiral carbon
What does a mutase do?
Moves sidechain from one carbon to another (intrachain)
What does a transferase do?
Moves sidechain from one substrate to another (interchain)
What does a Kinase do?
Phosphorylates using ATP
What does Phosphorylase do?
Phosphorylates using Pi
What does Carboxylase do?
Forms C-C bonds (w/ ATP and biotin)
What does a Synthase do?
Consumes 2 substrates
What does Synthetase do?
Consumes 2 substrates, uses ATP
What does a phosphatase do?
Breaks phosphate bond
What does a Hydrolaxe do?
Breaks a bond with water
What does a Lyase do?
Cuts C-C bonds w/ATP
What does dehydrogenase do?
Removes H with a cofactor
What does a Thio do?
Breaks S bond
What is Diffusion>
From high to low concentration
What is active transport?
Goes against concentration gradient
What is zero-order kinetics?
metabolism independent of concentration
What is first order kinetics?
Constant drug percentage metabolism over time, depends on drug concentration
What is Efficacy?
Max effect 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
What is Km?
Concentration of drug that produces 50% of receptors
What is EC50?
Concentration of drug that produces 50% of maximal response
What is competitive inhibition?
Fights for active site, no DeltaVmax, potency decreases
What is Non-competitive inhibition?
binds a regulatory site, no DeltaKm, efficacy decreases, decreases Vmax
What is Endothermic Reaction>
Consumes heat
What is Exothermic Reaction?
Gives of heat
What is the Peak level?
- 4 hrs after dose (too high => decrease dose)
What is the Through level?
2hrs before dose (too high=> gives less often)
What is t1/2?
Half life, the time it takes for the body to use half of the drug ingested
What is von Gierke?
G-6Pase deficiency=> hypoglycemia, hepatosplenomegaly
What is Pompe’s?
Cardiac alpha-1, 4-glucosidase deficiency => DIE early
What is Cori’s?
Debranching enzyme deficiency =>short branches of glycogen
What is Anderson’s?
Branching enzyme deficiency => long chains of glycogen
What is McArdle’s?
Muscle phosphorylate deficiency=> muscle cramps w/exercise
What is Essential Fructosuria?
Fructokinase deficiency => excrete fructose (still have hexokinase)
What is Fructosemia?
“fructose intolerance” (Aldolase B deficiency) => liver damage
What does a Galactokinase deficiency causes?
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, Niemman Pick
What lysosomal diseases have a Gargoyle-face?
Gaucher’s, Hurler’s
What is Tay-Sach’s?
Hexosaminidase A deficiency=> blindness, incoordination, dementia
What is Sandhoff’s?
Hexosaminidase A/B deficiency
What is Gaucher’s?
Glucocerebrosidase deficiency=> wrinkled tissue MP, bone pain