Biochem Session 3

Question 1

describe Km

Answer 1

a measurement for the affinity that an enzyme has for its substrate. in other words, at what concentration will the substrate be recognized by enzyme. Or Km is the [S] needed to saturate 50% of enzyme active sites, leading to 50% of maximum velocity. If there is only one active site per molecule, Km indicates how much substrate is needed to saturate 50% of enzyme molecules

Question 2

describe a committed step in a pathway

Answer 2

the conversion of A to B is the committed step, because once this occurs B is committed to being converted into F.

Question 3

what do allosteric enzymes catalyze

Answer 3

the committed step of metabolic pathways. Michaelis-Menten enzymes facilitate the remaining steps

Question 4

describe regulation of F via feedback inhibition

Answer 4

the pathway product F inhibits enzyme e1 by binding to a regulatory site on the enzyme that is distinct from the active site.

Question 5

what type of curve do allosteric enzymes have

Answer 5

a sigmoidal curve similar to hemoglobin