Enzymes (Unit 1)

Question 1

How can you increase the rate of a chemical reaction?

Answer 1

Temp, SA, concentration, catalyst

Question 2

Cellular activity of all living things in controlled through?

Answer 2

Enzymes

Question 3

Enzymes act as?

Answer 3

Catalyst to accelerate a reaction

Question 4

Almost all enzymes are?

Answer 4

Proteins (tertiary and quaternary structures)

Question 5

How are enzymes changed in a reaction?

Answer 5

Are not used up or permanently changed in the process, and do not change the products

Question 6

Enzyme shape

Answer 6

Each is unique and will determine the reaction the enzyme will catalyze

Question 7

Substrate

Answer 7

The specific reactant that an enzyme will bind with

Question 8

Active site

Answer 8

The location on the enzyme where the substrate binds. This site “fits” the substance

Question 9

Induced Fit Model

Answer 9

While each enzyme fits a specific substance, the enzyme is not rigid. Before the substrate binds, the active site changes its conformation to become even more precise in its ability to bind the substrate

Question 10

How are enzymes named?

Answer 10

After their substrate. Sucrase breaks down sucrose, proteases break down proteins, lipases break down lipids

Question 11

What must a reaction overcome in order to move forward?

Answer 11

Energy barrier known as the activation energy

Question 12

How do enzymes work?

Answer 12

They alter the substrate or its environment which lowers the activation energy required to perform the reaction, so the reaction occurs at a faster rate

Question 13

Factors Affecting Enzyme Activity

Answer 13

Cofactors and Coenzymes
Enzyme Inhibitors
Allosteric Regulation
Environmental Conditions

Question 14

Cofactor

Answer 14

A non-protein group that binds to an enzyme and is essential for catalytic function. Are often metals/minerals - iron, copper, zinc, manganese

Question 15

Coenzyme

Answer 15

Organic molecules that act as cofactors to enzymes. Usually vitamins

Question 16

Types of Inhibitors

Answer 16

Competitive and Non-competitive

Question 17

Competitive Inhibitor

Answer 17

Chemicals that resemble an enzyme’s normal substrate and compete with it for the active site preventing the substrate from binding

Question 18

Non-competitive Inhibitor

Answer 18

Do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, which alters the active site so the substrate cannot bind

Question 19

Allosteric Regulators

Answer 19

Important molecules that function to control chemical activity in a cell. Inhibition or Activation

Question 20

Allosteric Inhibition

Answer 20

When the product of the reaction is in excess, an inhibitor will bind to the enzyme, changing its shape and stopping enzyme activity and production of the product

Question 21

Allosteric Activation

Answer 21

When the product is at low levels, an activator will bind to the enzyme, changing its shape to allow the substrate to bind to the enzyme, increasing the rate of reaction

Question 22

Environmental Conditions

Answer 22

Temperature, pH, Ionic Concentration

Question 23

Temperature

Answer 23

Extreme temperatures are very dangerous

Question 24

pH

Answer 24

Most like 6-8, or near neutral. pH outside of the normal range causes enzymes to lose their structure. Optimal pH range may change

Question 25

Ionic Concentration (salt ions)

Answer 25

Interferes with protein folding changing the shape of the enzyme