Enzymes are bio-catalysts which enhance the rate of a reaction. They convert substrate into related products in the body.
Speed of enzyme reaction decides how fast the body physiology works.
They are very critical in the body as they control some of the important physiological functions.
Specific enzymes control functions like digestion, metabolism, absorption, excretion, penetration, blood clotting and even reproduction.
Unlike hormones, they are released and also act near the site of their production.
Even they are involved in detoxification of drugs and toxins in the body. Also enzymes proteins are targets for drug action.
Enzymes are present in both plants and animals.
Examples of enzymes
These are a group of enzymes involved in digestion of food in humans and animals. They are
- Amylase: Digests carbohydrates to breakdown into glucose.
- Lipase: Digests fats and oils to fatty oils for easy absorption.
- Pepsin, peptidases, Trypsin: Digests proteins into amino acids.
- Nucleases: Breakdown nucleic acids into nucleotides.
The enzymes examples mentioned are present near the gastrointestinal tract.
As the name indicates, these are the enzymes which aid in metabolism and also detoxification of substances in body. They are like
- Oxidases: These oxidase substances to alcohols or ketones etc.
- Hydrolases: These breakdown substance by addition of water.
- Reductases: These add hydrogen to a substrates in the reaction.
- Lyases: The enzymes which are involved in breaking of molecules without hydrolysis or oxidation.
- Ligases: Enzymes which brings in bonding of two or more molecules.
- Isomerases: These enzymes convert same molecule from one form to another and vice versa.
- Glucuronidase: This is the key enzyme which adds glucouronic acid to the non-water soluble substances and converts them to water soluble forms to be excreted through urine.
- Transaminases: These are enzymes involved in addition or removal of amino acids.
- Gycogensynthase: This is the enzyme which synthesizes glycogen from glucose to store in liver.
- Aminoacyl tRNA synthetase: This enzyme bind amino-acid to t-RNA.
- Lactate dehydrogenase: Enzymes which converts lactate to pyruvic acid.
Special enzymes in body
- Urokinase: Helps to breakdown clots in the body.
- Hyaluronidase: An enzyme secreted by sperm when released into female reproductive tract. This enzyme helps pierce through ova wall and merge with ova.
- DNA topoisomerase-II: The enzyme which catalyses cutting (nicking) and sealing function on DNA.
- DNA dependent RNA polymerase: An enzyme which helps in formation of mRNA.