# 0: Pre-Semester Review and Introduction


## Introduction to Bioinorganic Chemistry

What is bioinorganic chemistry? To answer this question, we should probably define what the other fields of chemistry are first...

You probably know that "biochemistry" is the study of the chemistry of biology - or life. The term "organic chemistry" literally means the chemistry of life. Organic chemistry is the study of carbon-based molecules because the first molecules that were isolated from living organisms contained carbon. On the other hand, the first minerals and other non-living things seemed to be made of other elements. For quite some time scientists naively assumed that all living things were made of carbon-based molecules, while non-living things did not contain carbon. "Organic chemistry" was the study of the carbon-based molecules of life, while "inorganic chemistry" was the study of "non-living" and "non-carbon" molecules.

Do these these historic definitions still hold true? To answer that question, let's look at one of the most important reactions in your life, shown below.

$O_2 + 4e^- + 4H^+ \rightleftharpoons H_2O$

Is this reaction carbon-based? Is it living? Well, take a deep breath! When you breath, you inhale mostly nitrogen gas (N2), but also some oxygen gas (O2). The oxygen gas that you inhale is critical for energy production in every one of your cells. During aerobic metabolism, O2 accepts 4 electrons and 4 hydrogen ions to become two molecules of water. This reaction provides the driving force for phosphorylation of ATP that is required to fuel countless other essential reactions that keep you alive. This reaction is responsible for all aerobic life. And, it's inorganic! This simple example shows how the historic names of organic and inorganic chemistry should not be taken literally.

There are additional inorganic components required for this reaction too! For example, most of the proteins of the electron transport chain (the proteins that catalyze reduction of oxygen in the mitochondria of your cells) require metal cofactors and metal active sites. Please watch the video below to see some examples. Articles about the individual proteins from the video are provided below.