Noun. 1. agoraphobia-a morbid fear of open spaces (as fear of being caught alone in some public place). phobia, phobic disorder, phobic neurosis-an anxiety disorder characterized by extreme and irrational fear of simple things or social situations; phobic disorder is a general term for all phobias. Translations.
Coenzyme [edit]. A coenzyme is a small, organic, non-protein molecules that carries chemical groups between enzymes. It is the cofactor for the enzyme and does not form a permanent part in the enzyme's structure. Sometimes, they are called cosubstrates and are considered substrates that are loosely bound to the enzyme. In metabolism, coenzymes play a role in group-transfer reactions, such as ATP and coenzyme A, and oxidation-reduction reactions, such as NAD+ and coenzyme Q10. Coenzymes are frequently consumed and recycled.
A substrate is the substance upon which an enzyme acts in an enzymatic reaction. Enzymes are biological catalysts that increase the rate of chemical reactions by decreasing the activation energy required for that reaction. An enzyme catalyzes a chemical reaction converting a substrate reactant to a product. An individual enzyme generally has more than one substrate and may be specific to several reaction intermediates that are part of an over-all reaction.