Enzymes Flashcards
(14 cards)
Allosteric enzymes are…
Enzymes that contain an active site plus allosteric sites. Binding of an effector at these sites causes conformational change which affects the binding affinity of the active site
What does an allosteric L-B plot look like?
It has a sigmoidal curve
What does a competetive L-B plot look like?
Same y intercept (b), but steeper slope
What does an uncompetetive L-B plot look like?
y intercept (b) is shifted higher, slope is the same (runs parallel)
What does an non-competetive L-B plot look like?
Different y intercept (b), steeper slope, same x intercept
Where do competetive inhibitors bind?
They compete with the substrate at the active site
Where do uncompetetive inhibitors bind?
It only binds to the enzyme-substrate complex
Where do non-competetive inhibitors bind?
They can bind both at the active site or the ES complex
What are three types of catalysis?
Acid-base, covalent, metal ion
What does the term “induced fit” imply?
The enzymes can rearrange after binding to specialize the fit of a certain substrate
What is the difference between cofactors and coenzymes?
Cofactors include small molecules and ions, while coenzymes refers specifically to small molecules
How are Vmax and KM affected by competetive inhibition?
Vmax is unchanged, KM is higher
How are Vmax and KM affected by uncompetetive inhibition?
Vmax decreases, KM decreases
How are Vmax and KM affected by noncompetetive inhibition?
Vmax decreases, KM doesn’t change
