Enzymes

Question 1

What are the types of catalysts?

Answer 1

• homogeneous (same phase or in same solution)

- heterogeneous (different phases)

Question 2

Where do reactions occur in enzymes?

Answer 2

active sites

Question 3

What are the steps of enzyme reaction?

Answer 3

1) absorption
2) reaction
3) desorption

Question 4

How can you increase the reaction rate of the enzyme?

Answer 4

• increasing the surface area (which increases the number of active sides)
• increasing the rate of transport to the active site (ex. stirring) which also increases the rate at which product is removed from the surface to prevent buildup

Question 5

What are the reactants of enzymes?

Answer 5

Substrates

Question 6

What are the steps to enzyme catalysis?

Answer 6

1) substrates must diffuse through the liquid phase to the enzyme
2) substrates are absorbed into the active site
3) the reaction occurs
4) the product desorbs
5) the product diffuse away

Question 7

What are the potential properties of enzymes?

Answer 7

1) higher specificity
2) higher rates of reaction
3) milder reaction condition

Question 8

What determines if the reaction is likely to happen?

Answer 8

the equilibrium constant

Question 9

How do enzymes and chemical catalysts differ?

Answer 9

enzymes are flexible

Question 10

What is the oriental effect mechanism?

Answer 10

enzyme can move to position the substrate(s) in the correct orientation for the reaction to occur

Question 11

What is the proximity effect mechanism?

Answer 11

enzyme moves the substrates into close proximity allowing them to react

Question 12

What are the types of reactions that require additional element beside the enzyme called?

Answer 12

cofactors

Question 13

What are the types of cofactors?

Answer 13

1) metals
2) coenzymes
3) co-substrates

Question 14

What are enzymes that are bounded to their cofactors called? What are they called when they are not bound to their cofactor?

Answer 14

holoenzymes when bounded

apoenzymes when not bounded

Question 15

Are enzyme active sites symmetrical? Why or why not

Answer 15

asymmetrical because amino acids are in their L-isomer

Question 16

Why are amino acids, carbohydrates, and lipids only found as specific isomers in nature?

Answer 16

the products that enzymes form are stereospecific

Question 17

What is the order of kinetics of enzymes?

Answer 17

• first order when the concentration of substrate is low

- zero order when the concentration of substrate is high

Question 18

When is steady state in enzyme reactions?

Answer 18

• when equilibrium is reached

- when [ES] plateaus

Question 19

What are factors that affect enzyme kinetics?

Answer 19

1) Temperature
2) pH - the state of ionization and deprotonation can affect the rate of reaction
3) substrate concentration