glucose in plants

[har0bed1813]

Because I am studing the most benificient environment for the working of photosynthesis, I would like to test the presence of glucose in the leaves and stem of a beanplant. What would you use to get a quantative assessment? (by the way, I am aware my english spelling and terminology are not that good, but I'm better at understanding and translating English into Dutch than the other way around)

grtz, debbie

[mith]

It's easier if you measure how many bubbles of oxygen given off by underwater plants...I'd do that but it sounds like you have to use beans.

[MrMistery]

measuring the level of glucose in a plant is really hard. It can be done, but it is a weird experiment. I would recommend puttiing the plant in a dark room and then, after 1-2 days take it to the sunlight but cover some part of the leaves. After letting it stay there a few hours take the leaf and color it with Lugol. You will see that only the part that was covered turnes blue. That way you have proved the dependednce of light on photosynthesis.
Another way would be measuring by how fast the beans reach maturity in each conditions however, this would take a while

[mith]

I forgot what the indicator is, but we used it in chemistry to detect simple sugars. You could grind your leaves and check. I dunno how you would make it quantitative though.

[MrMistery]

An indicator could be used but since glucose is always present it will not work since that only has 2 functions: glucose and non-glucose

[mothorc]

I dont know how to separate and measure the concentration of glucose on a mixture of sugar
But to measure the working of photosynthesis, you must measure the total carohydrate
You should build a schematic with protocol:
1ml succorse (1,2,3,4,5,6,7,8,9mg per ml)
+1ml phenol
+5ml H2SO4(100%)
OD490nm (abs )
Do again with your plant tissue
It 's seem not clearly but If you want I can give it clearly to you

[har0bed1813]

Thanx for your suggestion; but
1. Yes, I would like it clarified
2. Yes, I would like quantities, but sofar i cannot tell wether this methode is quantative.
3. This could work, because from what I can tell, the other components of a leaf won't interfere with determining glucose presence

[har0bed1813]

Your method includes Lugol... please clarify?
and secondly, What exactly does it indicate?