Glucose uptake and conversion

To Do: Create the model in Stella*. Use the mass action kinetics to describe the rate of reaction.
Run simulations with each of the parameter values indicated. Monitor the amount of glucose produced over time for each simulation experimental condition.

Kinetics: Mass action or Mass flux

Enzyme: glucose transporter, hexokinase (glucokinase)

System statements (disclaimers): ATP not taken into account.

 

  Reaction Kinetics (Rate law) Kinetic type Constants
Influx of Glucose Glucose   Facilitated diffusion

V

Km
  Glucose k irreversible mass action k
Conversion Michaelis-Menten

V

Km
  k*Glucose irreversible mass action k

Create the above model in Stella. Use the "Interface" window to attach sliders to the rate constant for hexokinase (k1) and glucose influx. Also add an input knob for the concentration of glucose. Set the range of values for the sliders and input knob to encompass the experimentally identified values given below in the parameter table. The input control knobs in Stella allow you to change the initial conditions of the simulation without having to open each object within the model.

Parameter Value mM/min refs. Value (Range) in Stella
Glucose transporter Vmax (k)

0.0197
55

(15)
(13)		 0.02- 55
Hexokinase Vmax (k) 0.84
51.7
68.5
242.8

(1)
(3)
(15)
(17)

 0.8- 240
Km 0.08 (1) NA

 

Variable Concentration (refs.) Value Range in Stella
Glucose 0.134
0.345
109 		(15)
(14)
(13)		 0.1-110
Glucose 6-phosphate 1.011
1.51		 (15)
(1) 		1-1.5

Run a few simulations and discuss the results.

Sample worksheet for class assignment.