Digestion of nucleic acids in human body

  • Nucleic acids are the components of our nuclear material (Chromosomes) present in the cells.
  • Nucleic acids are also ingested from food like herring, mackerel etc.
  • These nucleic acids are digested and metabolized in the digestive tract (small intestine) by a series of enzymes which are present in the pancreatic juice and intestinal juices.
  • The enzymes include endonucleases,nucleotidases and nucleosidases.

A. Pancreatic juice: It contains two nucleases (endonucleases):

1. Deoxyribonuclease (DNase): It splits or breaks down DNA into its component deoxyribonucleotides.

DNA —————>Deoxyribonucleotides

2. Ribonuclease (RNase): It splits or breaks down RNA into its component ribonucleotides.

 RNA ————> Ribonucleotides

B. Intestinal juice: It contains two types of enzymes for the hydrolysis of nucleotides.

1. Nucleotidases:

  • They are also known as nucleophosphatases.
  • They break the nucleotides (deoxyribonucleotides and ribonucleotides) into nucleosides (deoxyribonucleosides and riboncleosides) and inorganic phosphates.

Nucleotides ————–> Nucleosides + Inorganic phosphates

2. Nucleosidases:

  • These split the nucleosides (deoxyribonucleosides and ribonucleosides) into nitrogenous bases (purines and pyrimidines) and pentose sugars (deoxyribose and ribose).

Nucleosides ———–> Nitrogenous bases + Pentose sugars

  • The end products of the nucleic acid digestion are pentose sugars, nitrogen bases and inorganic phosphates.

Digestion of nucleic acids in human body