Bacteria are often used in industry as a source of enzymes. One reason is because bacteria divide rapidly, producing a large number of them in a short time.

Describe how bacteria divide.

Washing powders often contain enzymes from bacteria. These enzymes include proteases that hydrolyse proteins in clothing stains.

Figure 1 shows the effect of temperature on a protease that could be used in washing powder.

Explain the shape of the curves at 50 °C and 60 °C.

Some proteases are secreted as extracellular enzymes by bacteria.

Suggest one advantage to a bacterium of secreting an extracellular protease in its natural environment.

Explain your answer.

Mammals have some cells that produce extracellular proteases. They also have cells with membrane-bound dipeptidases.

Describe the action of these membrane-bound dipeptidases and explain their importance.