What is Biochemistry? What do Biochemists study? | Biology |

What is Biochemistry? The Chemistry of Life. You know about atoms and molecules from Chemistry. But there’s nothing ALIVE about chemistry. It’s just chemicals in a beaker. So what’s so special about the molecules
of life? It’s a case of emergent properties. That is, as biological molecules come together
and interact, new and surprising properties emerge that you wouldn’t predict. You can think of biology in terms of a structural
hierarchy. Atoms – molecules – cells – tissues – organs
– pretty soon you have a multicellular organism with a metabolism. Let’s start with atoms. Especially CHNOPS. Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus,
and Sulfur. These are the elements that make up 98% of
living matter on earth. We can study the behavior of these individual
atoms, but things get more interesting when these atoms interact. Bonds are formed and broken. We see the emergence of chemical behavior. Some of these atoms stay bonded together,
forming biological molecules. There are 4 main kinds of biological molecules: Proteins, Carbohydrate, Lipids, and Nucleic
Acids. Proteins are polymers of amino acids. That is, amino acids strung together to form
a chain. These strings of amino acids fold into 3 dimensional
shapes that do most of the work of life. With proteins, and all biological molecules,
the key to remember is that the 3D structure determines the function. Think of how a key fits into a lock. The shapes have to be just right for the key
and the lock to do their jobs. The jobs of proteins include structure, like
collagen, enzyme catalysts that control the rate of reactions, signalling, like some hormones,
immune function, like antibodies and antibody receptors…I could go on…all day. Carbs (carbohydrates) are sugars and polymers
of sugars. These are used for energy, and to build biological
structures. Lipids are nonpolar molecules, like fats,
oils, and phospholipids. These are important for energy storage, for
cushioning, and for structures like cell membranes. Nucleic Acids include DNA and RNA. These store genetic information. It’s important to note these are all carbon-based
molecules. This is why we say we are carbon-based lifeforms. The skeletons of biological molecules are
made up of carbon atoms, covalently bonded together in very stable structures. Hanging off the outside of the molecules are
functional groups – small chemical species like OH or CH3. Think of the carbon skeleton giving biological
molecules their general 3D shape, and the functional groups like flags hanging off,
participating in chemical reactions. We see another level of complexity emerge
when these biological molecules interact with each other. We get enzymes controlling reaction rates. We get DNA replication, and genetics. We get cells. And within cells, we have an incredibly diverse
set of chemical reactions that are controlled and run at just the right rates to keep us
all alive. That’s what biochemistry is. The building blocks of Life Itself. Our new Biology series will cover all of these
topics in more depth. Be sure to subscribe, so you’ll find out
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