In
biochemistry
Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a ...
, a synthase is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that
catalyses a
synthesis
Synthesis or synthesize may refer to:
Science Chemistry and biochemistry
*Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors
**Organic synthesis, the chemical synthesis of organi ...
process.
Note that, originally, biochemical nomenclature distinguished
synthetases and synthases. Under the original definition, synthases do not use energy from nucleoside triphosphates (such as
ATP,
GTP,
CTP,
TTP, and
UTP), whereas
synthetases do use nucleoside triphosphates. However, the Joint Commission on Biochemical Nomenclature (JCBN) dictates that 'synthase' can be used with any enzyme that catalyzes synthesis (whether or not it uses nucleoside triphosphates), whereas 'synthetase' is to be used synonymously with '
ligase'.
Examples
*
ATP synthase
ATP synthase is an enzyme that catalyzes the formation of the energy storage molecule adenosine triphosphate (ATP) using adenosine diphosphate (ADP) and inorganic phosphate (Pi). ATP synthase is a molecular machine. The overall reaction catalyzed ...
*
Citrate synthase
Citrate synthase ( E.C. 2.3.3.1 (previously 4.1.3.7)) is an enzyme that exists in nearly all living cells. It functions as a pace-making enzyme in the first step of the citric acid cycle (or Krebs cycle). Citrate synthase is located within euka ...
*
Tryptophan synthase
*
Pseudouridine synthase
*
Fatty acid synthase
Fatty acid synthase (FAS) is an enzyme that in humans is encoded by the ''FASN'' gene.
Fatty acid synthase is a multi-enzyme protein that catalyzes fatty acid synthesis. It is not a single enzyme but a whole enzymatic system composed of two ide ...
*
Cellulose synthase (UDP-forming)
*
Cellulose synthase (GDP-forming)
References
Ligases
{{Enzyme-stub