RP11 Flashcards
1
Q
Describe how a calibration curve could be produced for glucose
A
- Use distilled water and a glucose solution of known
concentration to produce a dilution series (of
glucose solutions of known concentrations) - Heat a set volume of each solution with a set
volume of Benedict’s solution - Measure absorbance (of light) of each solution
using a colorimeter - Plot a graph of absorbance (y axis) against
concentration of glucose solution (x axis) and
draw a line / curve of best fit
2
Q
Describe how the concentration of glucose in an unknown ‘urine’ sample
can be identified using a calibration curve
A
- Perform Benedict’s test on sample using same volumes of solutions used in producing calibration curve
- Measure absorbance using a colorimeter
- Absorbance value for ‘urine’ sample read off calibration curve to find associated glucose concentration
3
Q
Give examples of variables that should
be controlled
A
● Volume of sample used
● Volume of Benedict’s solution
● Temperature of water bath
● Time samples were heated for in water bath
4
Q
Explain why a high blood glucose
concentration can cause glucose to be
present in the urine of a diabetic person.
A
● Not all glucose reabsorbed at proximal convoluted tubule
● As glucose carrier / cotransporter proteins are saturated /
working at maximum rate