Question

same ddrug does not work against the microbes belonging to different groups.why?state the mechanism of the antibiotic in killing bacteria

Answer 1

Answer:

• Drugs kill or prevent the growth of microbes by targeting specific organelles or protein or essential component in the microbes. This varies from microbe to microbe and drug to drug.

• Drug targets microbes by four different mechanisms:

1. Altering the permeability of the cell membrane of the microbe.
2. Altering synthesis of cell wall in the microbe.
3. Altering the synthesis of DNA in the microbe.
4. Altering the synthesis of protein or enzyme in the microbe.

Explanation:

• Some drugs are capable of increasing the permeability of the microbe's cell membrane. The cell membrane losses its ability to function as a selectively permeable membrane. This can result in the uncontrolled loss of water, essential ions and bio-molecules from the microbial cell causing its death by dehydration.
• Cell wall in microbes provides them with protection. Some drugs are capable of inhibiting the enzymes responsible for synthesising the cell wall. In absence of the protective covering the microbe gets killed.
• Some drugs can inhibit the DNA polymerase or other essential enzymes responsible for the replication process. Lack of DNA synthesis prevents the multiplication of microbes.
• Many drugs are capable of inhibiting essential proteins and enzymes required by the microbe for its metabolism, survival or growth. Absence of those proteins can kill the microbes.