DSA 3: Fundamentals of Biochemical Reactions Flashcards
What is the free energy equation?
ΔG = ΔG°΄ + RTln(Products / Reactants)
When the body’s pH is low, what does it do?
Eliminate H+ and reabsorb HCO3-
When the body’s pH is high, what does it do?
Fewer H+ is eliminated and less HCO3- is reabsorbed
What is going on in respiratory acidosis?
Increase of CO2 due to hypoventilation.
This causes equilibrium to shift to left
What is going on in metabolic acidosis?
Strong acid present
This causes equilibrium to shift to left
What is going on in respiratory alkalosis?
Decrease of CO2 due to hyperventilation.
This causes equilibrium to shift to right
What is going on in metabolic alkalosis?
Strong base present
This causes equilibrium to shift to right
How do catalysts function in reactions?
They lower activation energy and increase reaction rate.
NO affect on ΔG
What are oxidoreductases?
Enzymes that transfer electrons from donor to acceptor
LEO GER (Lose electron - oxidized. Gain electron - reduced)
What are transferases?
Enzymes that transfer functional groups between molecules
What are isomerases?
Rearrange/isomerize molecules
What are lyases?
Add/remove atoms to form DOUBLE BONDS
What are ligases?
Bonds formed via hydrolysis of ATP
What are hydrolases?
Bonds are cleaved via addition of water
What is difference between cofactors and coenzymes?
Cofactors: metal ions
Coenzymes: organic molecules derived from vitamins
___ and ___ affect optimal enzyme activity.
Temperature and pH
What is Vmax?
Saturation of enzymes (max turnover)
What does it mean when Km is low and high?
High Km: low affinity for E-S complex
Low Km: high affinity for E-S complex
What is competitive inhibition? How does Km and Vmax change?
Inhibitor binds to enzyme at substrate binding site.
No change for Vmax
Increase in Km
What is noncompetitive inhibition? How does Km and Vmax change?
Inhibitor binds to enzyme and enzyme/substrate
Decrease for Vmax
No change in Km
What is unncompetitive inhibition? How does Km and Vmax change?
Inhibitor binds to enzyme/substrate complex only
Decrease for Vmax
Decrease in Km
What are allosteric enzymes?
They bind noncovalently to enzyme (not at catalytic site) and can have positive or negative affects.
They induce conformational changes to either enhance or inhibit substrate binding
What are isozymes?
They have same function but different properties and binding sites.
