AP BIOLOGY

Detailed explanation-1: -What is an antibiotic? Antibiotics are medicines that fight infections caused by bacteria in humans and animals by either killing the bacteria or making it difficult for the bacteria to grow and multiply.

Detailed explanation-2: -In order to be useful in treating human infections, antibiotics must selectively target bacteria for eradication and not the cells of its human host.

Detailed explanation-3: -Some, such as penicillin, kill bacteria by destroying the bacterial cell wall. Others, such as tetracycline, interfere with the ability of bacteria cells to reproduce or make proteins or nutrients they need to survive.

Detailed explanation-4: -Selective effects occur in selective compartments, where particular antibiotic concentrations result in a differential growth rate of resistant bacterial variants. This may happen even at very low antibiotic concentrations able to select low-level-resistant bacteria.

Detailed explanation-5: -The aim of antimicrobial therapy is to kill or inhibit the infecting organism without damaging the host; this is known as selective toxicity. This is commonly accomplished through the use of antimicrobial drugs.