1.1. Fig. 1 shows a model of how an enzyme works.

Fig. 1

Label the enzyme molecule on Fig. 1.

1.2. Enzymes are biological catalysts.

(i)

Explain what is meant by the term catalyst.

[2]

(ii)

State why enzymes are important in organisms.

[1]

1.3. Sketch in the appearance of an enzyme-substrate complex on the diagram in Fig. 1.

The diagram is provided again here for you. 

Fig. 1

1.4. Extended only

Describe the action of enzymes.

Use the following words as part of your answer:

collide     complementary     randomly     recycled