Question

A sugar cube (sucrose) weighs about 3 g. A 20 oz. (591 mL) container of Gatorade (or Powerade) contains 35 g of sucrose (table sugar). 1.0 oz. = 28.35 g. Sucrose is a dissaccharide consisting of glucose and fructose (a 1:1 ratio). Gram molecular weight (GMW) of sucrose = 342.2 g/mole. When ingested, sucrose is rapidly broken down into glucose and fructose by enzymes in your body. In humans, normal blood glucose levels are maintained at about 0.005 moles/L (which = 5.0 milllimoles/L, or 5.0 mM). Assume that your total blood volume is 5 L (average human). You drink a 20 oz. container of Gatorade. What is the molarity of glucose in your blood after drinking the Gatorade?

Answer 1

Molar mass of sucrose = 342.2 g/mol

Mass of sucrose in 20 oz. Gatorade = 35 g

Moles of sucrose in 20 oz. Gatorade = 35/342.2 g = 0.1023 mol

Now, 1 mole sucrose on enzymatic reaction produces 1 mol glucose.

Therefore, 0.1023 mole sucrose on enzymatic reaction produces 0.1023 mol glucose.

Total volume of blood = 5 L

Therefore moles of glucose per L of blood = 0.1023/5 = 0.020 mol/L

Normal blood glucose levels are maintained at about 0.005 mol/L.

Therefore, after consuming 20 oz Gatorade total concentartion of glucose in blood = (0.020 + 0.005) mol/L

                                                                                                                                   = 0.025 mol/L

                                                                                                                                   = 0.025 M

Hence, molarity of glucose in your blood after drinking the Gatorade = 0.025 M