Chapter 25.5, Problem 5AYLO

Summary Introduction

To discuss:

The brush border enzymes of the small intestine and their functions.

Introduction:

Microvilli are a type of internal projections in the small intestine. These are smaller extensions of the plasma membrane that forms a brush border on every enterocyte’s surface. Brush border enzymes are present in the plasma membrane that carry out the final stages of the digestion process. These enzymes are not secreted into the lumen, so chyme reaches the brush border for digestion. This activity is known as contact digestion. This increases the surface area by a factor of 20.