Enzymes.

Question 1

What are enzymes?

Answer 1

Biological catalysts made of protein- this means they speed up a reaction without being used up themselves. Once a reaction is finished they can be used to catalyse the same type of reaction again.

Question 2

Functions of enzymes are:

Answer 2

• Building larger molecules from small ones, such as in protein synthesis.
• Breaking down large molecules into smaller ones, such as in digestion.

Question 3

What do enzymes look like?

Answer 3

Enzymes, like all proteins, are made up of long chains of amino acids.
These are folded together to form a specific shape. The shape of the active site of the enzyme is particularly important, as it is where molecules of other substances bind to the enzyme.

Question 4

What is the substrate?

Answer 4

The molecule that binds to the enzyme and fits inside it.

Question 5

Do enzymes bind to all molecules?

Answer 5

Enzymes are highly specific, meaning they can only bind to one type of substrate molecule. The substrate must fit exactly into the active site, or else the molecule cannot bind.

Question 6

Explain the Lock-And-Key Hypothesis.

Answer 6

You can think of the enzyme being like a lock, and the substrate like a key. Only one key will fit the lock and be able to turn to open the door. This is the way scientists think enzymes work.

Question 7

How do enzymes work?

Answer 7

When the substrate binds to the enzyme, an enzyme-substrate complex is formed. The reaction then happens quickly, and the products are released from the enzyme. The enzyme is then ready to catalyse another reaction.

Question 8

How do enzymes build large molecules from smaller ones?

Answer 8

The substrate molecules arrive and fit into the enzyme’s active site, and the bond forms. The substrate molecules will then have a bond formed between them, and the product molecule will leave and the enzyme is free to catalyse another reaction of this type.

Question 9

How are enzymes used to break down large molecules into smaller ones?

Answer 9

The large substrate molecule will arrive and fit into the enzyme’s active site, and the bond forms. The substrate molecule will then have a bond broken down inside them, and the two smaller product molecules will leave and the enzyme is free to catalyse another reaction of this type.

Question 10

What do you call the joined version of an enzyme and substrate?

Answer 10

The enzyme-substrate complex.