3.3 enzymes and activation energy

Question 1

What are enzymes (3 points)

Answer 1

1. help chemical reactions
   take place at LOWER energy levels
2. DO NOT supply energy for reactions
3. Help speed up the rate of reactions

Question 2

Enzymes are almost always

Answer 2

proteins

Question 3

Enzymes are usually written __________________

Answer 3

above the reaction arrow

Question 4

Activation energy

Answer 4

amount of energy
required to start a reaction

Question 5

Transition State

Answer 5

temporary state between
reactants and products (before new bonds are formed)

Question 6

when does transition state occur

Answer 6

occurs when enough energy is required to begin reaction

Question 7

What provides activation energy?

Answer 7

1. thermal energy
2. catalyst (enzymes)

Question 8

How does Thermal Energy provide Ea

Answer 8

Often cause more reactions to take place as more energy is released - hard to regulate

Question 9

How does catalysts provide Ea

Answer 9

-Allows reactions to occur using less energy
-Can be regulated to control rates of reaction

Question 10

How can enzymes lower activation energy

Answer 10

1. Bring reactants together
2. Charged enzymes help break bonds
3. Enzyme changes shape of substrate

Question 11

How do enzymes bring reactants together

Answer 11

Orients molecules into position so they can bind

Question 12

How do CHARGED ENZYMES HELP BREAK BONDS

Answer 12

Charged functional groups help to attract
reactants and break bonds

Question 13

How does an enzyme change the shape of a substrate

Answer 13

Enzyme changes shape to change the shape of the
substrate and break bonds