Final answer:
Penicillins are practically ideal antibiotics due to their effectiveness against gram-positive and certain gram-negative bacteria. However, they can cause severe allergic reactions, and some bacteria have developed resistance to these antibiotics. Penicillins work by inhibiting bacterial cell wall synthesis, leading to the bursting of bacterial cells.
Step-by-step explanation:
Penicillins are considered practically ideal antibiotics due to their effectiveness against gram-positive bacteria, such as diphtheria, pneumonia, and syphilis. They are also effective against certain gram-negative bacteria, including Escherichia coli. Penicillin G, the earliest penicillin used on a wide scale, is unstable in the acidic pH of the stomach and cannot be administered orally. However, penicillin V, ampicillin, and amoxicillin are acid-stable and can be taken orally.
The principal adverse effects of penicillins include allergies. Around 5% of the population is allergic to penicillin, and the allergic reaction can be severe, leading to fatal coma if penicillin is mistakenly administered. Fortunately, several other antibiotics have been discovered that can be used as alternatives. Additionally, some strains of bacteria have developed resistance to penicillins and related compounds, which has prompted scientists to continue seeking new antibiotics to combat these resistant strains.
Penicillins work by inhibiting bacterial cell wall synthesis, causing defective walls and the bursting of bacterial cells. This mechanism of action only affects bacteria, as human cells do not have cell walls like bacteria do.