Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: Active absorption of D-glucose and D-galactose by intestinal tissue of the chiton Cryptochiton stelleri (Middendorff, 1846)
Student Author(s): Robbins, Kenneth B.
Faculty Advisor(s): Fuhrman, Frederick A.
Pages: 24
Location: Final Papers Biology 175H
Date: June 1974
Keywords: chiton
Abstract: 1. The uptake of D-glucose and D-galactose by the intestine of Cryptochiton stelleri (Middendorff, 1846) was studied in vitro by the accumulation of sugar within intestinal tissue. 2. Proximal anterior intestinal tissue actively absorbs D-glucose. 3. Proximal posterior intestinal tissue actively absorbs D-glucose and D-galactose, via a separate transport system. 4. The posterior intestinal D-glucose transport system is apparently incapable of transportin 3-0-methylglucose, a non-metaboizable glucose analogue in other transport systems. 5. D-galactose uptake by the posterior intestine is very slow in mammalian terms (Vmax = 0.81 mN/hr), although the D-galactose transport system of Cryptochiton stelleri shows a greater sensitivty (Km = 0.1mM) to D-galactose than does the equivalent system in hamster intestine. This indicates a slow but efficient accumulation of D-galactose at low concentrations by this invertebrate.