Enzymes

Question 1

what are enzymes?

Answer 1

Proteins that acts as biological catalysts.

Question 2

How do enzymes work?

Answer 2

One area of the enzymes is called the active site, which is specific to a certain substrate.
When the enzyme and substrate bind they form a complex, which lasts until the reaction is complete.

Question 3

What is meant by specific active site?

Answer 3

The 3d stucture of each enzyme is unique due to the side chains and branches that are present. This also makes the active site unique, and therefore only the substrates that match each active site can bind there.

Question 4

Differentiate between intracelluar and extracelluar enzymes.

Answer 4

• Intracellular - catalyse reactions inside the cell e.g. RNA polymerase
• Extracellular - catalyse reactions outside the cell e.g. Amylose

Question 5

What is activation energy?

Answer 5

The activation energy is the amount of energy that must be put in for the reaction to begin.

Question 6

How do enzymes lower the activation energy?

Answer 6

• provide an alternative, lower energy pathway.
• provide a more favourable pH in the active site
• They put strains on bonds in the substrate to break them
• they bring reactants close together so bonds are easier to form

Question 7

What is the induced fit theory?

Answer 7

The enzyme changes shape to fit the substrate when the substrate is near.

Question 8

What is the lock and key theory?

Answer 8

• Random movement causes the enzyme and substance to collide, the substrate enters the active site.
• Enzyme-Substrate complex forms; charged groups attract and help bonds break or form
• Products are released and the enzyme is unchanged ready to accept another substrate.