Biochemistry studies the chemistry of living things. It looks at the molecules and reactions that keep cells alive, from the energy in food to the code in DNA.
The field draws on organic, analytical, and physical chemistry. Researchers use those tools to understand how molecules are built, how they change, and how they interact inside living organisms.
Four classes of molecules do most of the work: carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates and lipids store and supply energy. Proteins do the work of the cell, from speeding up reactions to building structures. Nucleic acids, DNA and RNA, carry the instructions for making proteins.
The chemistry of life rests on a small set of elements. Carbon, hydrogen, nitrogen, and oxygen make up the bulk of living matter. Calcium and phosphorus also play major roles, especially in bones, teeth, and energy transfer.
Metabolism is the sum of the chemical changes in an organism. Some reactions break molecules down to release energy. Others build complex molecules from simpler ones. Together they keep the organism running.
Biochemistry has practical reach. In medicine it underpins drug design, diagnostics, and our understanding of genetic disease. In agriculture it guides crop nutrition, pest control, and plant breeding. Subfields include enzymology, which studies the proteins that speed up reactions, and molecular genetics, which studies how genetic information is stored and used.
Students interested in the field usually start with chemistry and biology coursework before specializing. Related reading: careers with a biology degree, STEM tutoring, and STEM research grants.
