Tag: enzymes

Enzymes are the biological catalyst which catalyzes biological reactions within a narrow range of temperature and pH. Certain thermophiles have enzymes which remain functional even at very high temperatures. Most of the enzymes are proteins in nature but a few enzymes are RNA in nature. They are called as catalytic RNAs or ribozymes.

The conjugate protein consists of two parts protein and non-protein part. Non-protein part is the cofactor and protein part is apoenzymes. Complete conjugate protein is known as Holoenzymes. Apoenzyme is an inactive enzyme. Thus, the correct option is D.

A constant indicating the substrate concentration at which an enzyme catalysed reaction attains half its maximum velocity or 1/2 V$ _{max}$ is known as Michaelis-Menten constant or K$ _m$. Lower K$ _m$ indicates more affinity between the enzyme and substrate and consequently higher reaction rates.

The reactants do not undergo chemical change automatically. They do so in transition state. Transition state has more free energy than reactants or products. The inability of reactants to undergo change due to requirement of extra energy for converting them to transition state is called as 'Energy Barrier'. Energy required to overcome energy barrier is called as 'Activation Energy'.

The suffix -ase  is used for the nomenclature of the enzyme. It is used at the end of the substrate. For example, the enzyme that breaks down peroxides are known as peroxidases. Hexokinase are the enzyme which helps in synthesis of hexose sugar. In 1898 Duclaux proposed the suffix -ase.

The enzymes are protein in nature and they are generally produced in inactive form so to protect the intracellular damage of protein. For example,  digestive enzymes are secreted in form of zymogens which remains inactive in the cells in which it is produced. The active sites are blocked by the peptide which keeps the enzyme in the inactive stage so the other proteins do not get harmed by the reaction. Cleavage of this peptide cleaves activates the enzyme.