Enzymes and Coenzymes

Enzymes are biological catalysts that accelerate chemical reactions, while coenzymes are small organic molecules that assist some enzymes by carrying electrons or chemical groups.

Connect

Enzyme catalysis: The acceleration of chemical reactions by enzymes through substrate binding and stabilization of reaction pathways. It explains how enzymes speed reactions without being consumed.
Protein structure: The three-dimensional organization of a protein, from its amino-acid sequence to assemblies of multiple chains. Most enzymes rely on folded protein structures to form functional catalytic sites.
Metabolism: The network of chemical reactions that sustains life by transforming matter and energy. Enzymes and coenzymes coordinate the reactions that make up metabolic pathways.
Ribozyme: An RNA molecule that catalyzes a chemical reaction. Ribozymes show that catalytic biological molecules need not be proteins.
Eduard Buchner: A German chemist whose cell-free fermentation experiments established that fermentation could occur without intact living cells. His work helped show that biochemical catalysis can be studied outside living cells.
Active site: The region of an enzyme where substrates bind and chemical catalysis occurs. Its shape and chemistry determine substrate recognition and catalytic action.
Amino acid: An organic molecule containing amino and carboxyl groups; amino acids are the building blocks of proteins. Their side chains supply the chemical properties used in enzyme active sites.
Drug metabolism: The enzymatic transformation of drugs into compounds that can be eliminated or act differently in the body. Enzyme activity determines how many medicines are activated, altered, or cleared.
Abzyme: An antibody engineered or selected to catalyze a chemical reaction. Abzymes contrast ordinary enzyme evolution with catalytic activity built from antibodies.
Frederick Gowland Hopkins: A British biochemist who helped establish the importance of vitamins and metabolic intermediates in biology. His work on accessory dietary factors helped frame the study of coenzymes.