Have you ever suffered from strep throat, an ear or mouth infection, tuberculosis or syphilis? If so, you have had a bacterial infection and have probably consulted your doctor. He prescribed you an antibiotic called penicillin. Penicillin is a life-saving drug and was the beginning of antibiotics. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”?Get the original essayPenicillin is a type of medicine called an antibiotic that kills bacteria, but what are bacteria? Bacteria, named after the Greek word for "little stick," were first discovered in the late 1600s. They are single-celled organisms found everywhere on earth. Bacteria are prokaryotes, meaning they lack a nucleus. All cells store their genetic information, called DNA, in a nucleus. So where do bacteria store theirs? Bacteria store their DNA in a single loop that floats around their cytoplasm. Most bacteria are useful; they live in our intestines and help us digest food. Only a handful of bacteria are harmful; these bacteria are called pathogens. Pathogens infect you, reproduce, and produce toxins that damage your body and can eventually kill you. Although pathogens can be very dangerous, your body has ways to fight them. Your body's first line of defense is actually bacteria. The good bacteria in your gut eliminate any pathogens that could make you sick. Some also produce chemicals that kill bad bacteria. After bacteria, your body has white blood cells that create antibodies that inhibit or kill the bacteria. You are also very hot. Hot temperatures, or fevers, are caused by chemical signals sent to the part of your brain that regulates your body temperature. Heat creates a hostile environment that kills bacteria. Even with all the measures your body takes to defend itself against bacteria, sometimes it just doesn't work. Bacteria reproduce at an alarming rate and can mutate frequently to adapt to any conditions. This is why penicillin is a life-saving medicine. Before the era of penicillin and antibiotics, there was no effective way to treat bacterial infection; You could get blood poisoning from a simple cut or scratch. Hospitals were always full of people with bacterial infections. There were treatments, such as sulfonamides, but they were ineffective in most cases. They also had antiseptics, but these were only good for sterilization and were toxic to the body. Alexander Fleming was credited with the initial discovery of penicillin. Fleming was professor of bacteriology at Saint Mary's Hospital, London. He was trying to create antiseptics that were not harmful to animal tissues when he found Penicillium Notatum, a mold, in one of his petri dishes containing staphylococci. The mold secreted a juice that killed the bacteria around it, so Fleming began to study it and named it "mold juice." He then named the mold juice penicillin. He discovered that penicillin stops bacteria by destroying their cell walls and preventing them from forming new ones. This means that bacteria cannot reproduce and.