Enzyme Action Flashcards
(12 cards)
What types of protein are enzymes?
Enzymes are globular proteins
What are globular proteins?
Protein molecules where the tertiary structure has given the molecule a generally rounded, ball shape
Describe what an enzyme is:
Enzymes are globular proteins, that act as catalysts
What are catalysts?
Catalysts are substances that alter the rate of a chemical reaction without undergoing permanent changes themselves
How many times can you use an enzyme?
Enzymes can be used repeatedly, therefore making them effective in small amounts
What can enzymes do/not do?
Enzymes can lower the activation energy in reactions, therefore allowing reactions to take place at lower temperatures and speeding them up.
They do not however, make reactions happen
What are the conditions required for a chemical reaction to occur?
- Molecules must collide with sufficient energy in order to alter the arrangement of their atoms to form their products
- The free energy of the products must be less than that of the substrates
- An initial amount of energy (activation energy)
What is the meaning of activation energy?
The minimum amount of energy needed to activate a chemical reaction
What is the structure of an enzyme?
Enzymes have a specific 3D shape and a specific region which is functional. This is known as the active site.
Describe the lock and key model of enzyme action
The lock and key model states that the active site of the enzyme has a fixed shape that the substrate attaches to, when complementary, due to successful, random collisions
Describe the induced fit model of enzyme action
The induced fit model states that the active site is almost complementary to the substrate but it changes shape slightly to fit the substrate
How do enzymes lower activation energy?
They distort the substrate’s bonds which make the chemical reactions easier
