Active Transport in Insect Malpighian Tubules

 

Dee Silverthorn

Tested Studies in Laboratory Teaching, 1995, Volume 16

Abstract

The Malpighian tubules of insects are an excellent model for examining the properties of secretion in a transporting epithelium. In this exercise students expose tubules from cockroaches or crickets to chlorophenol red and visually estimate the dye concentration in the lumen. By adding metabolic inhibitors and competitors or by substituting ion-free media they can demonstrate competition, specificity, and energy- or ion-dependence of active transport. Advanced students can design their own experiments after a review of the literature. This simple and inexpensive exercise provides students with a challenging and rewarding introduction to experimental design in the laboratory.

Keywords:  active transport, secretion, Malpighian tubule, epithelium

Emory University (1994)