You incubate same human epithelial cells in vitro at 32 degr

You incubate same human epithelial cells in vitro at 32 degree C, 37 degree C, and 42 degree C. You see that glucose uptake by the cells is highest at 37 degree C. but inhibited at both 32 degree C and 42 degree C. The uptake of the dye eosin is lowest at 32 degree C, but increases as incubation temperature increases. Explain these results.

Solution

The transporter proteins and enzymes have optimum temperature to exhibit their maximum activity. Below or above the optimum temperature, these proteins become inactive or exhibit minimum activity. For glucose uptake by epithelial cells, the optimum temperature required is 37⁰ C and below and above this temperature (32⁰ and 42⁰C) the transport protein that uptake glucose exhibits minimum acrivity.

The lipophilic dye eosin uptake is lowest at 32⁰ C and is increased with increase in incubation temperature. This is because, the high temperatures make the cell membranes porous due to which the the dye easily enter into the epithelial cells. The lipids in the epithelial membrane become gel like at high temperature and become solid at low temperatures. When the epithelial cells are gel like, they allow the eosin dye to enter into the cells.