Enzymes

Question 1

Enzymes

Answer 1

Protein catalysts - speed up chemical reactions without being consumed

Question 2

Chemical Reactions Without Enzymes

Answer 2

In non-catalyzed environments, reactions occur in a random and uncontrolled manner (slow) - reactant molecules must collide with enough force (energy) and with the correct geometric orientation for bonds to break

Question 3

Activation Energy and Enzymes

Answer 3

Energy that must be overcome for a chemical reaction to occur –> most reactions get energy from heat, but proteins denature from heat
- Enzymes lower activation energy by holding chemical reactants in correct orientation

Question 4

Enzyme-Substrate Complex

Answer 4

Substrate (reactant) binds to active site (where catalysis occurs) on enzyme –> fits closely since enzymes can adjust their shape slightly (induced fit)

Question 5

Conditions

Answer 5

• Enzyme-catalyzed reactions can be saturated, but speed of reaction cannot increase indefinitely by increasing concentration of substrate (active sites get filled up)
• Each enzyme has optimal temperature and pH that it works best at (due to particle theory and denaturation)

Question 6

Nonprotein Cofactors

Answer 6

Inorganic substances (ex. Zn & Mg) or organic coenzymes (ex. some vitamins) that some enzymes require to work properly

Question 7

Inhibitors

Answer 7

Chemicals that bind to specific enzymes, resulting in change in shape of enzyme, which shuts it down

Question 8

Competitive Inhibition

Answer 8

Chemical compounds bind to active site of enzyme and compete with true substrate for access to active site (ex. penicillin blocks enzymes of bacteria)

Question 9

Non-Competitive Inhibition

Answer 9

Inhibitor molecule binds to allosteric site of enzyme resulting in change in 3D structure of enzyme, preventing substrate from binding to active site

Question 10

Activators

Answer 10

Molecules that bind to allosteric site that promote action of enzymes