Enzymes which are secreted inside the cell and catalyze intracellular metabolic reactions are called endoenzymes. Example- hexokinase, glycogen synthase etc. Enzymes which are secreted outside the cell and act on a particular extracellular substrate is called exoenzymes. Example- any digestive enzyme like lipase, pepsin, trypsin etc.
Most enzymes are of protein nature. But there are some exceptions. For example, a few RNA molecules show some catalytic action. These RNA molecules are known as ribozymes. These are actually ribonucleoprotein particles, i.e., made up of protein and RNA, but only RNA portion shows catalytic activity. Example- RNase P in E. coli acts as [...]
Several enzyme activities are indicated at different sites of the same protein (large polypeptide) macromolecule for catalyzing different consecutive reactions of a metabolic pathway. So long the molecule stays as a single molecule its active sites catalyze the respective reactions in a specific sequence and release the final product. Such a macromolecule is called a [...]
Enzymes having only one polypeptide chain are called as monomeric enzymes. Example- DNA polymerase I of E. coli. Enzymes having more than one polypeptide chain are called as oligomeric enzymes. Examples- pyruvate kinase, lactate dehydrogenase etc.
An enzyme is a biocatalyst that increases the rate of chemical reaction without being changed in the overall process. Enzymes change covalent bonds of some biochemical substances and transform that substance to a new substance. The substance that undergoes covalent modification is known as substrate of that enzyme and the newly produced substance is known [...]
