Endoprotease is a class of enzymes that breaks down proteins by cleaving peptide bonds. Some common synonyms for endoprotease are protease, proteinase, peptidase, and endopeptidase. Protease refers to any enzyme that breaks down proteins, while proteinase specifically refers to enzymes that break down proteins by hydrolyzing peptide bonds. Peptidase is a broader term, encompassing both endoproteases and exopeptidases, which cleave proteins from the ends rather than the middle. Endopeptidase is another term for endoprotease, emphasizing the enzyme's function of cleaving peptide bonds within a protein. Overall, these synonyms are used interchangeably in scientific literature and research.