Question

Does our blood have proteases and nucleases?

Answer 1

Proteases and nucleases are known as the enzymes that take part in digestion of proteins and nucleic acids respectively. Human blood does not have either of these enzymes, rather blood serum contains a protease inhibitor to protect blood proteins from protease action.

Complete answer:
Proteases also called peptidases or proteinases, are enzymes that catalyze proteolysis, the breakdown of proteins into smaller polypeptides or single amino acids. They do this by breaking the peptide bonds present within proteins by hydrolysis. Proteases catalyze various biological processes like protein processing, regulation of protein function, apoptosis, viral pathogenesis, digestion, photosynthesis, and numerous other vital processes.
Nucleases are known as a broad and diverse category of enzymes that hydrolyze the phosphodiester bonds of nucleic acids (DNA and RNA). They are classified into ribonucleases (RNases) that act on RNA and deoxyribonucleases (DNases) that act on DNA. Nucleases may vary in their functions and selectivity for certain types of nucleic acid substrates, and thus can be further classified into distinct categories. Most nucleases are specific, though their degree of specificity varies greatly.
Human blood does not include these enzymes, nucleases and proteases. In human beings, blood serum comprises various types of protease inhibitors that protect the blood proteins from being broken down by the action of proteases. The enzyme, nucleases, is also found absent in the blood.

Note:
In humans, blood serum contains different types of protease inhibitors, which inhibit the breaking down of blood proteins by the action of proteases. The enzyme, nucleases that catalyze the hydrolysis of nucleic acids (DNA and RNA) is also absent in the blood.