A few notes about words in the article on penicillin that could be confusing:
Medical research is investigations to learn more about the causes, prevention, and treatments of diseases. Medical researchers may grow (culture) bacteria in gelatin or a similar medium (which in this case means the material in which they grow). Scientists then analyze that culture (group of cells-- or of bacteria).
This specialized meaning of ‘culture’ is the one used in this article. (‘Culture’ usually means a human group’s complete way of life-- the meaning discussed in the first issue of the English Detective newsletter.)
Dr. Fleming was growing a bacterial culture that accidentally (not by plan or on purpose) got contaminated (mixed with something else, so it was no longer pure) by a mold (in this case a tiny form of plant life related to fungi). Dr. Fleming noticed that the mold killed the bacteria, and realized it might help people who were infected with that bacteria.
Other scientists were involved in learning the structure (chemical form) of the antibacterial chemical compound that the mold produced, which they called Penicillin. They were then able to produce Penicillin synthetically (producing the chemical themselves, rather than taking it from the mold.) This enabled large-scale manufacturing, so that there would be enough Penicillin produced to meet the need for it.
* To conduct an experiment is to carry it out (perform or “do” it.) To conduct can also mean to lead (as a conductor leads an orchestra or guides a train), Conduct is also a noun meaning behavior. (Good conduct is conducting or guiding oneself appropriately-- acting the way parents, teachers, or other authorities want. So prisoners can get out of jail in the U.S. early for “good conduct.")
You might also be interested in a word search puzzle on the methods of science and answers (using all the vocabulary words mentioned at the beginning of newsletter 2.) Some people find that word searches help them notice and learn vocabulary. (They can be especially helpful if you think of the meaning or use of each word you have already learned.) If you don’t find word searches helpful, just skip it!