Rate Of Reaction

Question 1

What is the energy needed to make a reaction happen called?

Answer 1

Activation energy

Question 2

What is the short hand for activation enrgy?

Answer 2

Ea

Question 3

What effect to enzymes have on Ea?

Answer 3

Enzymes work by reducing the Ea.

Ea lowered-means it is easier for reaction to happen

Question 4

What are the 2 possible effects of a rise in temperature?

Answer 4

Increases kinetic energy.
Either more enzyme-substrate complexes or
Denaturation

Question 5

How does an increase in temperature increase enzyme-substrate complexes?

Answer 5

Molecukes have more kinetic energy meaning enzymes and substrates are more likely to collide

Question 6

How does an increase in temperature dentaure an enzyme?

Answer 6

Molecules vibrate more which can break bonds and alter a molecules structure.

Question 7

What happens at low temperatures?

Answer 7

There is low kinetic energy. Few enzyme-substrate complexes being formed so rate of reaction is slow. q

Question 8

Are enzymes denatured at low temperatures?

Answer 8

No

Just low energy

Question 9

What is an enzymes optimum temperature?

Answer 9

Where the rate of reaction is at its highest. Enough energy to increase enzyme-substrate complex formation but not enough to dentaure enzymes.

Question 10

What is the optimum temperature for most enzymes in the body?

Answer 10

37°C

Question 11

What happens when pH is changed away from the norm?

Answer 11

Bonds start to change.
Active site changes shape.
Too far from the norm the enzyme is denatured.

Question 12

What is the graph of pH and reaction rate?

Answer 12

Bell shape over optimum pH

Question 13

What does pH effect on an enzyme?

Answer 13

Charges on R groups. Hydrogen and Ionic bonds between R groups.

Question 14

What is the optimum pH for stomach enzymes?

Answer 14

pH of about 2

Question 15

What haopnes as substrate concentration increases?

Answer 15

Rate of reaction increases.

Question 16

Why does the rate of reaction increase with substrate concentration increase?

Answer 16

Extra substrate means more likely to collide with enzyme. Forms enzyme-substrate complex

Question 17

What does the graph of substrate concentration and rate of reaction look like?

Answer 17

Steady inacrease then flatten out.

Enzymes working at optimum rate.

Question 18

Why can an enzyme never reach its true optimum?

Answer 18

Due to the time taken for products to leave an active site and a new substrate to enter.

Question 19

What happens when enzyme concentration is increased?

Answer 19

Rate of reaction increases.

Question 20

What is a limiting factor?

Answer 20

A factor limiting the rate of the process.

Where increasing the level of that factor increases the rste but other factors have no effect.

Question 21

What are allosteric activators?

Answer 21

Conpunds that can activate enzymes to make he active site change shape so the substrate can now fit.