penicillin was called a" mircle drug" because it doesnt harm cell. why doesnt it?
Penicillin is often referred to as a "miracle drug" because it has the ability to fight off bacterial infections without harming human cells. Understanding why penicillin doesn't harm human cells requires some knowledge about its mechanism of action.
Penicillin belongs to a class of antibiotics called beta-lactam antibiotics. These drugs target the bacterial cell wall, which is an essential structure that provides structural support and protection for bacterial cells. The bacterial cell wall is made up of a complex network of peptides and sugars called peptidoglycan.
Penicillin works by interfering with the formation of this peptidoglycan layer in bacterial cell walls. It does so by inhibiting the action of an enzyme called transpeptidase, which cross-links the peptides in the peptidoglycan structure. This disruption weakens the bacterial cell wall, making it unable to withstand the internal pressure of the cell, leading to cell lysis and death.
The reason penicillin doesn't harm human cells is due to the differences between bacterial and human cell walls. Human cells lack a peptidoglycan layer in their cell walls. Instead, human cells have a different type of cell membrane that is composed of lipids and proteins. This structural difference makes penicillin specific to targeting bacterial cells without affecting human cells.
Furthermore, penicillin is designed to specifically target bacteria and has a minimal effect on the body's healthy cells. It is a selective antibiotic, meaning it specifically targets certain types of bacteria while sparing others. This selectivity is determined by the specific receptors or enzymes present in bacteria that are not present or function differently in human cells.
However, it is important to note that some individuals may still experience side effects or allergic reactions to penicillin. Allergies can occur due to an individual's immune response to the drug, rather than direct harmful effects on human cells.
In summary, penicillin is called a "miracle drug" because it effectively targets and eliminates bacterial infections by disrupting the bacterial cell wall, without harming human cells, due to the differences in cell wall structure and selective targeting mechanisms.