ai Flashcards
What technique is most widely used to determine the 3D structure of enzymes?
X-ray crystallography
What does trypsin cleave on?
The carboxyl side of Arg or Lys
What specific bonds does thrombin cleave?
Arg-Gly bonds in particular sequences
What determines the specificity of an enzyme?
The 3D-structure of the enzyme
What are cofactors?
Metal ions or organic molecules
What role do many coenzymes serve in enzymatic reactions?
Intermediate carriers or functional groups in conversion of substrate to product
When a coenzyme is firmly associated with an enzyme, what is it known as?
A prosthetic group
Do many enzymes require cofactors for activity?
Yes
How are enzymes classified?
By the reaction they catalyse
What is the pH optimum for pepsin?
Acidic conditions
At what pH does carbonic anhydrase function optimally?
Neutral pH of plasma and cell cytoplasm
What is the optimum function condition for trypsin?
Alkaline conditions
In competitive inhibition, what happens to Km on the Lineweaver-Burke plot?
Km increases
What is methotrexate a structural analogue of?
Tetrahydrofolate
What enzyme does methotrexate specifically inhibit?
Dihydrofolate reductase
What is the effect of non-competitive inhibition on Vmax?
Vmax is decreased
In non-competitive inhibition, what happens to Km?
Km is unchanged
Where does the inhibitor bind in non-competitive inhibition?
At a site distinct from the active site
What does cyanide inhibit?
Enzymatic activity (specifically, it can inhibit cytochrome c oxidase)
