Chapter 24, Problem 4TE

How does chemotherapy work to fight a disease or infection?

To determine

To fight disease and infection how chemotherapy works.

Answer to Problem 4TE

In chemotherapy drug is use to destroys disease causing agent without destroying the animal host.

Explanation of Solution

To remain healthy humans and bacteria use folic acid as nutrient human can synthesis folic acid from food whereas the bacteria need to produce it. They possess receptor site that help make folic acid from a simpler molecule found in all bacteria para-amino benzoic acid (PABA).The PABA attach to the specific receptor site and get converted into the folic acid as shown in Fig(1).

Fig. (1)

Sulfa drugs have close resemblance to PABA. When taken by a person suffering from a bacterial infection, a sulfa drug is transformed by the body into the compound sulfanilamide which attaches to the bacterial receptor sites designed for PABA as shown in Fig.(2).This prevents the synthesis of folic acid,without folic acid bacteria die but he or she lives on the folic acid received from the diet

Fig. (2)

Conclusion:

Therefore, drug is use to destroys disease causing agent without destroying the animal host.