lecture 22B - enzymology

Question 1

describe the transition state of enzyme kinetics

Answer 1

high unstable

energetically unfavourable

reaction intermediate

Question 2

what Is the structure and function of enzymes?

Answer 2

lowering the activation energy of reaction at transition state (but delta G remains the same)

Question 3

describe the substate binding in enzyme kinetics

Answer 3

the active site is nearly the correct shape. the active site has a high affinity for the substate and conforms the shape of the enzyme to fir the substrate. it involves intermolecular bonds between functional groups in substrate and active site

Question 4

what are the bonding forces involved in substrate binding?

Answer 4

ionic

hydrogen

van der Waals

Question 5

what is induces fit?

Answer 5

active site alters the shape to maximise intermolecular bonding

Question 6

what describes the overall process of enzyme catalysis?

Answer 6

binding interactions must be strong enough to hold substrate long enough for reaction

interactions must be weak enough to allow product to depart

Question 7

describe competitive inhibition

Answer 7

competitive inhibitor binds at the active site of the enzyme. it resembles the active site. competitive inhibitors can be overcome by increasing substrate concentration.

Question 8

what is an example of a competitive reversible inhibitor?

Answer 8

methotrexate and fluorouracil

Question 9

describe non competitive inhibition

Answer 9

the inhibitor can only bind in the absence of substrate. changes the shape of the active site

Question 10

uncompetitive inhibition

Answer 10

inhibitor can only bind in presence of substrate