Co-Enzymes
Objective
At the end of this
lecture, student will be able to
• Explain Co-enzymes
Coenzymes
• The protein part of the enzyme, on its own, is not always
adequate to bring about the catalytic activity.
Many enzymes require certain nonprotein factors, collectively referred
to as coenzymes or cofactors
• Cofactors may be organic or inorganic in nature
• The non-protein, organic, Iow molecular weight and
dialysable substance associated with enzyme function is known as coenzyme
• The functional enzyme is referred as holoenzyme which is
made up of a protein part (apoenzyme) and a non-protein part (coenzyme)
• The term prosthetic group is used when a non-protein moiety
is tightly bound to the enzyme which is not easily separable by dialysis
• The term activator is referred to the inorganic cofactor
like Ca2+, Mg2+,
Mn2+ etc. necessaryt o enhance enzyme activity
• Coenzymes undergo alterations during the enzymatic
reactions, which are later regenerated
• Various types of Coenzymes are studied indetailed under
water soluble vitamins
• Simply coenzymes are obtained from B-complex vitimines
Non-vitamin
coenzymes:
• Not all coenzymes are vitamin derivatives. There are some other organic substances,
which have no relation with vitamins but function as coenzymes, considered as
non-vitamin coenzymes
Summary
• The non-protein, organic, Iow molecular weight and
dialysable substance associated with enzyme function is known as coenzyme