| allosteric |
Pertaining
to the altered activity of an enzyme due to the binding of a molecule to a region other
than the enzyme’s active site. |
| anabolism |
The energy-consuming
process of incorporating nutrients into protoplasm through biosynthesis |
| catabolism |
The
chemical breakdown of complex compounds into simpler units to be used in cell metabolism |
| catalysts |
A substance that alters
the rate of a reaction without being consumed or permanently changed by it. In cells,
enzymes are catalysts |
| coenzymes |
A
complex organic molecule, several of which are derived from vitamins (e.g., nicotinamide,
riboflavin). A coenzyme operates in conjunction with an enzyme. Coenzymes serve as
transient carriers of specific atoms or functional groups during metabolic reactions |
| cofactors |
An enzyme accessory. It
can be organic, such as coenzymes, or inorganic, such as Fe, Mn, or Zn ions. |
| constitutive enzymes |
An
enzyme present in bacterial cells in constant amounts, regardless of the presence of
substrate. Enzymes of the central catabolic pathways are typical examples. |
| enzymes |
A protein biocatalyst
that facilitates metabolic reactions |
| exoenzyme |
An
extracellular enzyme chiefly for hydrolysis of nutrient macromolecules that are otherwise
impervious to the cell membrane. It functions in saprobic decomposition of organic debris
and can be a factor in invasiveness of pathogens |
| fermentation |
The extraction of
energy through anaerobic degradation of substrates into simpler, reduced metabolites. In
large industrial processes, fermentation can mean any use of microbial metabolism to
manufacture organic chemicals or other products |
| glycolysis |
The
energy-yielding breakdown (fermentation) of glucose to pyruvic or lactic acid. It is often
called anaerobic glycolysis because no molecular oxygen is consumed in the degradation. |
| holoenzyme |
An enzyme complete with
its apoenzyme and cofactors. |
| hydrolysis |
A
process in which water is used to break bonds in molecules. Usually occurs in conjunction
with an enzyme |
| labile |
In chemistry, molecules
or compounds that are chemically unstable in the presence of environmental changes. |
| metabolites |
Small
organic molecules that are intermediates in the stepwise biosynethsis or breakdown of
macromolecules |
| negative feedback |
Enzyme regulation of
metabolism by the end product of a multienzyme system that blocks the action of a
"pacemaker" enzyme at or near the beginning of the pathway. |
| oxidized |
In
chemical reactions, the loss of electrons by one reactant. |
| redox reactions |
Denoting an
oxidation-reduction reaction |
| substrate |
The
specific molecule upon which an enzyme acts |
