Enzyme Mechanisms Flashcards
Test: fill in the blanks
What does the symbol represent? The larger or smaller value the better? And why?
True or false: catalysts, hence also enzymes, do not affect the equilibrium of a reaction?
True!
Enzymes use a lot of mechanisms, what are the five common mechanisms we for sure need to know?
What is the rule for the “curved arrow convention”?
Acid-Base Catalysis reactions involve what?
What are the three types of Acid-Base Catalysis?
Proton transfer!
What type of catalysis does RNase use?
Concerted Acid-Base Catalysis.
What does RNase A do? What is it?
An endonuclease which leaves the P-O bond shown in blue and indicated with a blue arrow.
It cleaves RNA in the digestive tract into small pieces.
Cleaves single-stranded RNA.
(This is why it doesn’t have much nucleotide sequence preference.)
Define Endonuclease and where it’s used.
Means cleave in the middle.
Used in RNase Nomenclature.
Define Exonuclease and where it’s used.
Means to cleave at either end.
Used in RNase nomenclature.
(So cleave either on 5’ or 3’ end, 1 amino acid)
What is the structure of RNase A?
What is this reaction using as its enzyme?
RNase A
What step is this in the RNase A catalytic reaction. What’s happening in this step?
Releases 3’ end!
What step is this in the RNase A catalytic reaction. What’s happening in this step?
Release 5’ end
Explain how metal ion catalysis works, and the three main things it can contribute. And how it workswith this reaction.
- They directly bind to substrate
- Mediate oxidation reduction reactions where they can transfer electrons to and from the substrate.
- Provide electrostatic stabilization.
Explain how proximity and orientation catalysis work.
By orienting substrates.
Explain and define how Covalent Catalysis works.
Define biological nucleophiles.
Define biological electrophiles.
Explain and define Transition State Stabilization.
You are making favorable changes to ES not just E or P.
