1) Write briefly about two different mechanisms by which antibiotics work.
It is possible for enzymes to involve themselves in the manufacturing of the cell wall. If a cell wall fails to develop because the final cross-linking reactions that make the cell wall rigid are not catalyzed, an antibiotic such as penicillin can be used to fit into the active site of the enzyme that was to catalyze such a reaction. As the penicillin attaches, a covalent bond complex is formed that cannot be removed.
Antibiotics can also affect enzymes which catalyze metabolic reactions that can be found in bacteria. Sulfa drugs enable humans to obtain the folic acid coenzyme. Since they resemble PABA, they can be effective to the human diet because PABA is what is converted to folic acid by bacteria using enzymes. While these enzymes catalyze metabolic reactions in bacteria, they do not alter human metabolism.
2) Write briefly about two different mechanisms by which some bacteria resist antibiotics.
Some bacteria possess a beta-lactamase enzyme that can open the lactam ring (penicillin is a beta-lactam and contains a 4 membered beta-lactam ring). If the ring is opened the compound is ineffective and harmless to the bacteria.
Some bacteria are resistant because they have conversions in their cell walls that do not allow entry to the antibiotic.
3) Write briefly about two different approaches scientists are trying to combat antibiotic resistance Pharmacologists have tried to help the beta-lactamase problem by making penicillin derivatives that are able to withstand the hydrolytic enzyme In the example of patients with AIDS, the patient should take several types of drugs each for different enzymes reducing the risk that a variant will surface and will be able to resist the drugs.