|Today, scientists find useful applications for compounds from nature but their search methods have changed. Biochemists analyze plants, microorganisms, but many of the things they work with are small even to be seen with a microscope, so they use chemicals to perform experiments. Many of these new inventions are enzymes, biological molecules that are like catalysts for chemical reactions. Sometimes, the only way to get useful organic compound is to get the organism that contains it. But improvements in science, useful compounds can now often be reproduced in a laboratory and sometimes they can be made by genetic engineering. For examples, insulin is a hormone important to human digestion. Many people with diabetes must take insulin as a medicine.
A journal is a periodical publication intended to further progress of science, usually by reporting new research. Most journals are highly specialized, although some of the oldest journals publish articles, reviews, editorials, short communications, letters, and scientific papers across a wide range of scientific fields. Journals contain articles that peer reviewed, in an attempt to ensure that articles meet the journal's standards of quality, and scientific validity. Each such journal article becomes part of the permanent scientific record.