Question
When a person has high blood sugar concentrations GLUT 4 follows ____ kinetics.
Answer
When a person has high blood sugar concentrations GLUT 4 follows zero-order kinetics.
Reasoning: When a person has high blood sugar concentrations, these transporters will still permit only a constant rate of glucose influx because they will be saturated (zero-order kinetics). Then how can cells with GLUT 4 transporters increase their intake of glucose? By increasing the number of GLUT 4 transporters on their surface.
Real World: Diabetes mellitus is caused by a disruption of the insulin/GLUT 4 mechanism. In type 1 diabetes, insulin is absent and cannot stimulate the insulin receptor. In type 2 diabetes, the receptor becomes insensitive to insulin and fails to bring GLUT 4 transporters to the cell surface. In both cases, blood glucose rises, leading to immediate symptoms (increased urination, increased thirst, ketoacidosis) and long-term symptoms (blindness, heart attacks, strokes, nerve damage).
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Glucose entry into most cells is driven by ____.
Normal glucose concentration in peripheral blood is ____ mM.
There are four glucose transporters, called ____.
Sodium-Dependent Glucose Transporters are called ____.
GLUT 2 is a ____-affinity transporter in hepatocytes and pancreatic cells.
GLUT 2 is a low-affinity transporter in ____ cells.