Final answer:
Brush border enzymes are the enzymes located on the surface of the small intestine's absorptive cells, responsible for the final stages of enzymatic digestion. They complete the breakdown process by working directly on the luminal surfaces of the intestinal cells.
Step-by-step explanation:
The enzymes found on absorptive cell surfaces in the small intestine that carry out the final stages of enzymatic digestion are Brush border enzymes. These enzymes are integral to the plasma membranes of the microvilli on absorptive cells. Unlike other enzymes that function within the digestive lumen, brush border enzymes operate on the luminal surface of the intestinal cells, effectively completing the digestion of nutrients. For example, enzymes such as maltase, lactase, and sucrase break down disaccharides into monosaccharides, while others like aminopeptidase and dipeptidase finalize the digestion of proteins.
In addition to the brush border enzymes, pancreatic enzymes play a critical role in digestion within the small intestine. Pancreatic juice, which contains enzymes like pancreatic amylase and proteolytic enzymes such as trypsin and chymotrypsin, is secreted into the small intestine where it continues the chemical breakdown of macronutrients.
It is important to note that the small intestine is not only the site for the majority of chemical digestion but is also where almost all nutrient absorption occurs. The presence of microvilli, with their brush border enzymes, greatly increases the surface area and the efficiency of both digestion and absorption.