What is biochemistry?
How is biochemistry related to regular chemistry?
Living organisms have a very complex chemistry, producing proteins, carbohydrates, nucleic acids (including DNA and RNA), lipids (fats and oils), and other biomolecules such as hormones.
The study of these molecules, and especially of the processes involved in making these molecules, is called biochemistry. A closely related and overlapping field is called molecular biology. Genetics, which once dealt only with inheritance, is now mostly a branch of biochemistry or molecular biology, since the discovery of DNA and the ability to sequence an organism’s genetic code.
Biochemistry links the functions of an organism to the proteins and other biomolecules involved in its makeup. Molecular biology relates the genes in an organism to the proteins and biomolecules that the genes code for. Genetics relates the genes of an organism to the functions of the organism. Together, the three disciplines form the foundation of modern biology and medicine.
There are groups of biomolecules that are of particular importance to biochemists.
Carbohydrates are sugars and things made from sugar. They are called carbohydrates because they have a chemical formula where there is one carbon for every water molecule. Simple sugars can be joined to form disaccharides (like table sugar) or longer chains of sugars like starch, cellulose, and pectin.
Lipids are long chains of carbons, attached at one end to a glycerin molecule by a fatty acid end. Short chained lipids with kinked tails make oils. Longer chains, or chains that are flexible and unkinked, can lie flat against one another easily, forming more solid fats.
Proteins are long chains made up of molecules called amino acids. Your skin, hair, and muscle are made of protein, and proteins called enzymes control almost every chemical reaction that happens in your cells.
Nucleic acids are the building blocks of DNA and RNA, the long molecules that encode how proteins are made in cells. This is the code that determines whether an organism is a tree, a frog, or a human.