The

Circe Circe (; grc, , ) is an enchantress and a minor goddess in ancient Greek mythology and religion. She is either a daughter of the Titan Helios and the Oceanid nymph Perse or the goddess Hecate and Aeëtes. Circe was renowned for her vast kno ...

effect is a phenomenon proposed by

William Jencks William Platt Jencks (August 15, 1927 – January 3, 2007) was an American biochemist. He was noted particularly for his work on enzymes, using concepts drawn from organic chemistry to understand their mechanisms. Career Jencks graduated from ...

seen in chemistry and

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 ...

where in order to speed up a reaction, the ground state of the substrate is destabilized by an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

Mechanism

Highly favourable binding of a substrate at a non-reactive site will force the reactive site of the substrate to be more reactive by putting it in a very unfavourable position. This effect was observed in

orotidine 5'-phosphate decarboxylase Orotidine 5'-phosphate decarboxylase (OMP decarboxylase) or orotidylate decarboxylase is an enzyme involved in pyrimidine biosynthesis. It catalyzes the decarboxylation of orotidine monophosphate (OMP) to form uridine monophosphate (UMP). The f ...

. This can occur by positioning a charged amino acid group next to the charged substrate thus destabilizing it, thus making the reaction occur faster. Furthermore, the substrate is put into an optimal position by the enzyme for the reaction to occur, thus decreasing the

entropy Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodyna ...

greatly.

Etymology

This process was named after

in Homer's ''

Odyssey The ''Odyssey'' (; grc, Ὀδύσσεια, Odýsseia, ) is one of two major Ancient Greek literature, ancient Greek Epic poetry, epic poems attributed to Homer. It is one of the oldest extant works of literature still widely read by moder ...

'', who lured men and turned them into pigs.

References

Biomolecules Catalysis Metabolism Process chemicals Circe {{chem-stub