Question

LSMUMU PILIHTUULL We can use Michaelis-Menten kinetics to understand transport of solutes through facilitated transport. GLUTI is a glucose transporter found in many cells. The Kos of GLUT1 for D- glucose is 1.5mM, and the Vmax for GLUT1 transport of glucose is 500 pmoles transported per milliliter of cells. A population of cells expresses only GLUT1 and no other glucose transporter. You examine the kinetics of glucose transport under various conditions and graph the rate of glucose transport against glucose concentration in the graph below. , umoles D.glucose/mL cells glucose Match the cellular condition with the curve on the graph. For each answer provide a brief justification for your choice. 7. Untreated cells expressing normal GLUT1 Intre Cells treated with GLUT1 inhibitor that entirely blocks GLUT1 activity Cells expressing a mutant GLUT1 with a higher Km that normal GLUT1 10. Cells expressing normal GLUT1, but half the normal number of transporters

Answer 1

A Michelis-Mento protein exhibits a hyperbolic curve.

An inhibitor increases the Km i.e. shifts the curve to the left.

The complete absence of protein activity is represented by dotted line-d.

At half the protein concentration, Vmax is reduced to half.

See the image.

Untreated cells expressing normal GLUT1 __Cells treated with GLUT1 inhibitor that entirely blocks GLUTI activity Cells expressing a mutant GLUTI with a higher K that normal GLUTI 10. Cells expressing normal GLUT1, but half the normal number of transporters