← Previous revisionRevision as of 06:15, 15 November 2026 Line 2: Line 2: {{Use dmy dates|date=June 2023}} {{Use dmy dates|date=June 2023}} [[File:Macromolecular-juggling-by-ubiquitylation-enzymes-1741-7007-11-65-S1.ogv|thumb|350px|Visualization of [[ubiquitylation]]]] [[File:Macromolecular-juggling-by-ubiquitylation-enzymes-1741-7007-11-65-S1.ogv|thumb|350px|Visualization of [[ubiquitylation]]]] '''Enzyme catalysis''' is the increase in the [[reaction rate|rate]] of a [[process]] by an "[[enzyme]]", a [[Biomolecule|biological molecule]]. Most enzymes are proteins, and most such processes are chemical reactions. Within the enzyme, generally catalysis occurs at a localized site, called the [[active site]]. '''Enzyme catalysis''' is the increase in the [[reaction rate|rate]] of a [[process]] by an [[enzyme]]. Most enzymes are proteins, and most such processes are chemical reactions. Within the enzyme, generally catalysis occurs at a localized site, called the [[active site]]. Most [[enzyme]]s are made predominantly of proteins, either a single protein chain or many such chains in a [[multiprotein complex|multi-subunit complex]]. Enzymes often also incorporate non-protein components, such as metal ions or specialized organic molecules known as [[Cofactor (biochemistry)|cofactor]] (e.g. [[adenosine triphosphate]]). Many cofactors are [[Vitamin|vitamins]], and their role as vitamins is directly linked to their use in the catalysis of biological process within metabolism. [[Catalysis]] of [[Biochemistry|biochemical reactions]] in the [[cell (biology)|cell]] is vital since many but not all metabolically essential reactions have very low rates when uncatalysed. One driver of protein evolution is the optimization of such catalytic activities, although only the most crucial enzymes operate near catalytic efficiency limits, and many enzymes are far from optimal. Important factors in enzyme catalysis include [[Acid catalysis#General catalysis|general acid and base catalysis]], orbital steering, entropic restriction, orientation effects (i.e. lock and key catalysis), as well as motional effects involving [[protein dynamics]]{{cite journal | vauthors = Kamerlin SC, Warshel A | title = At the dawn of the 21st century: Is dynamics the missing link for understanding enzyme catalysis? | journal = Proteins | volume = 78 | issue = 6 | pages = 1339–1375 | date = May 2010 | pmid = 20099310 | pmc = 2841229 | doi = 10.1002/prot.22654 }} Most [[enzyme]]s are made predominantly of proteins, either a single protein chain or many such chains in a [[multiprotein complex|multi-subunit complex]]. Enzymes often also incorporate non-protein components, such as metal ions or specialized organic molecules known as [[Cofactor (biochemistry)|cofactor]] (e.g. [[adenosine triphosphate]]). Many cofactors are [[Vitamin|vitamins]], and their role as vitamins is directly linked to their use in the catalysis of biological process within metabolism. [[Catalysis]] of [[Biochemistry|biochemical reactions]] in the [[cell (biology)|cell]] is vital since many but not all metabolically essential reactions have very low rates when uncatalysed. One driver of protein evolution is the optimization of such catalytic activities, although only the most crucial enzymes operate near catalytic efficiency limits, and many enzymes are far from optimal. Important factors in enzyme catalysis include [[Acid catalysis#General catalysis|general acid and base catalysis]], orbital steering, entropic restriction, orientation effects (i.e. lock and key catalysis), as well as motional effects involving [[protein dynamics]]{{cite journal | vauthors = Kamerlin SC, Warshel A | title = At the dawn of the 21st century: Is dynamics the missing link for understanding enzyme catalysis? | journal = Proteins | volume = 78 | issue = 6 | pages = 1339–1375 | date = May 2010 | pmid = 20099310 | pmc = 2841229 | doi = 10.1002/prot.22654 }}