Enzyme Facts Flashcards
What is the function of enzymes?
Lower activation energy of rxns
Enzymes biochemically are _____, except for _____.
Proteins, ribozymes
Enzymes catalyze _____ rxn / rxn type, exhibiting what?
Specific, optimal specificity
Enzymes only act on what isomer of an AA? Of a sugar?
L-isomer, D-isomer
Enzymes _____ used up in the rxn
Are NOT (E + S —> ES —> E + P)
True/False: Enzymes alter the equilibrium constants
False
True/False. Enzymes change the ∆G of the rxn
False
∆G
Free energy
Exergonic rxns have a _____ and occur _____.
-∆G, spontaneously (no energy used/needed)
Endergonic rxns have a _____ and require _____.
+∆G, energy input
What 2 factors affect enzymes?
Temp + pH
Why does temp affect enzymes?
Enzymes work over a very narrow range of temp in humans
What happens to rxns when ^ temp? What happens to enzymes at temp > 102˚F?
^ rxn rate. Proteins (enzymes) denature
What happens to rxn rates when temp < 98˚F?
Slows down
Why does pH affect enzymes?
Enzymes have an optimal pH
Pepsin is found in _____ and is an example of an enzyme with what optimal pH?
Stomach, Acidic: 1.5 - 2.0
Carbonic Anhydrase is found in _____ and is an example of an enzyme with what optimal pH?
RBCs, Neutral: 7.3 - 7.4
Trypsin is found in _____ and is an example of an enzyme with what optimal pH?
Sm Intestine, Basic: 8.0 - 9.0
Draw + label the Michaelis-Menten Curve. What are the typical units for the X + Y axis?
How is Km determined?
Km: [S] when rate = 1/2 Vmax
What is Km?
Estimated physiological [substrate]
What is Vmax?
Max rxn velocity
Describe the effects of [S] on activity of enzymes. Does this happen to all enzymes?
Michaelis-Menten Curve
(E+S —> ES —> E+P)
MANY, but not all, enzymes
What plot is Lineweaver-Burke plot? Draw + label the plot.
Double reciprocal
