molecular biology. (mÉ-lÄk'yÉ-lÉr) The branch of biology that deals with the formation, structure, and function of macromolecules essential to life, such as nucleic acids and proteins, including their roles in cell replication and the transmission of genetic information.
Molecules containing more than two atoms are termed polyatomic molecules, e.g., carbon dioxide (CO2) and water (H2O). Polymer molecules may contain many thousands of component atoms. A water molecule is made up of two hydrogen atoms and one oxygen atom. A single oxygen atom contains six electrons in its outer shell, which can hold a total of eight electrons. When two hydrogen atoms are bound to an oxygen atom, the outer electron shell of oxygen is filled. EncyclopÃ¦dia Britannica, Inc.
The terms molecule, compound, and atom can be confusing! Here's an explanation of what a molecule is (and is not) with some examples of common molecules. Answer: Molecules form when two or more atoms form chemical bonds with each other. It doesn't matter if the atoms are the same or are different from each other.ll compounds are molecules; not all molecules are compounds. Single atoms of elements are not molecules. A single oxygen, O, is not a molecule. When oxygen bonds to itself (e.g., O 2, O 3) or to another element (e.g., carbon dioxide or CO 2), molecules are formed.