Explanation:

Penicillin is an antibiotic drug that was discovered by Alexander Fleming in 1928. It is used to treat bacterial infections caused by sensitive bacteria. Penicillin is a member of the beta-lactam family of antibiotics, which means that it contains a beta-lactam ring in its chemical structure.

Interference in Metabolic Pathway of Bacteria:

Penicillin works by interfering in the metabolic pathway of bacteria. Bacteria require cell wall synthesis for their growth and survival. The cell wall is a complex structure that surrounds the bacterial cell and provides protection and support. The cell wall is primarily composed of peptidoglycan, a mesh-like structure of sugar and amino acids.

Penicillin interferes with the cell wall synthesis of bacteria by inhibiting the enzyme transpeptidase, which is responsible for cross-linking the peptidoglycan strands. Without the cross-links, the cell wall becomes weak and unable to withstand the high osmotic pressure of the bacterial cytoplasm. As a result, the bacterial cell undergoes lysis (rupture) and dies.

Penicillin is effective against a wide range of bacteria, including Streptococcus pneumoniae, Staphylococcus aureus, and Neisseria gonorrhoeae. However, some bacteria have developed resistance to penicillin by producing enzymes called beta-lactamases, which break down the beta-lactam ring and render the drug ineffective.

Conclusion:

In conclusion, penicillin is an antibiotic drug that works by interfering in the metabolic pathway of bacteria. It inhibits the enzyme transpeptidase, which is responsible for cross-linking the peptidoglycan strands in the bacterial cell wall. Without the cross-links, the cell wall becomes weak and unable to withstand the high osmotic pressure of the bacterial cytoplasm, which leads to cell lysis and death.