Chapter 7 + 8 Flashcards
(22 cards)
What is a first order reaction
Depends on just substrate
What is a metalloenzyme
Enzyme tightly binds metal ions for structure and function often transition metals
What is metal activated enzyme
Enzyme weakly binds metal ions often alkali and alkaline earth metals
What do metal ions do
Stabilize increased electron density
Enhance nucleophilicity of a group
Ionizable groups are most effective as H donor or acceptor ________
Close to pka
Good nucleophiles are ____ form
And examples are
Base form (neg)
Hydroxyl
Sulfhydryl
Amino
Imidazole
What is proximity and orientation effect
Bring substrates and reactive groups close to increase concentration increasing proximity and can orient for efficient catalysis
What does enzyme activity increase at high temperatures
Enzyme denatures
Explain how penicillin works
D-ala D-also goes through covalent catalysis normal function
D-ala D-ala looks like penicillin penicillin gets covalently bound and irreversible so bacteria dies and feel better
What happens when increase [I]
Alpha increase
Km app increases
More inhibition
What happens when decrease Ki
Alpha will increase
Tighter I binding
What happens when increase substrate in competitive inhibition
V max
Km and alpha neglect
2 things true about competitive inhibitors
Binding of substrate is exclusive
Substrate and inhibition are substrate or transition state analogs
Competitive inhibition effect on V max and Km
Km increase
V max doesn’t change
What is affected in uncompetitive inhibitions and by what factor
V Max and Km are affected equally by factor of 1/alpha prime
When is Km equal to Kd
When K2 is so much smaller than K1
What does the Michaelis menten equation describe
The kinetics of simple one substrate reactions
Michaelis constant Km is
Substrate concentration that yields 1/2 Vmax
What is a turnover number
K2 or kcat
What is measure of enzyme efficiency
K cat / Km
In a sequential reaction a ____ is formed
Ternary complex
What is the catalytic triad and function of each component
Serine histidine and aspartate
Aspartate orients his
His serves to position serine and polarizes hydroxyl (makes neg by taking proton from serine) the neg alkoxide is a good nucleophile
(General base)
See stabilizes covalent catalysis
