Leaf starch experiment
- Kathryn
- Posts: 390
- Joined: 01 Jun 2006, 10:00
- Job Title: Lab Technician
- School: Cedars Christian College
- Suburb: Farmborough Hts, Wollongong
- State/Location: NSW
Leaf starch experiment
Hi guys,
We are trying to do the experiment with varigated geranium leaves, boiled in meths, then soaked in iodine soln, to indicate the presence of starch on the green parts of the leaves and not present on the white parts of the leaves. But it is not working!!! Anyone else do this experiment and if so what are your secrets for success?
Kathryn
We are trying to do the experiment with varigated geranium leaves, boiled in meths, then soaked in iodine soln, to indicate the presence of starch on the green parts of the leaves and not present on the white parts of the leaves. But it is not working!!! Anyone else do this experiment and if so what are your secrets for success?
Kathryn
Re: Leaf starch experiment
We have done it with varigated leaves, but we had more success with dark green ones. We cover half of the leaf with alfoil in the garden, must be on sun, so when you finish decorating, looks like a xmas tree.
Students (or you) pick the leaves off next day and boil it in metho (use water baths, so as not to burn down the building). Rinse in water ,place on watch glass and cover with iodine solution. Make sure it is quite dark in colour. You will see the colour change on the leaves very soon. Kids get creative and make patterns on the leaves with some parts covered in different shapes.
Good luck
Lada
Students (or you) pick the leaves off next day and boil it in metho (use water baths, so as not to burn down the building). Rinse in water ,place on watch glass and cover with iodine solution. Make sure it is quite dark in colour. You will see the colour change on the leaves very soon. Kids get creative and make patterns on the leaves with some parts covered in different shapes.
Good luck
Lada
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Re: Leaf starch experiment
Hi there,
We have good success with this experiment, but our method may be a little different. We boil the leaves first in water, then place in a test tube with metho which is in a beaker of water on a hotplate. Remove the leaf, flood with iodine solution. Young, soft leaves work best. Try a paddle pop stick across the leaf. Leave a day or two before using method above.
Good luck, Ellice
We have good success with this experiment, but our method may be a little different. We boil the leaves first in water, then place in a test tube with metho which is in a beaker of water on a hotplate. Remove the leaf, flood with iodine solution. Young, soft leaves work best. Try a paddle pop stick across the leaf. Leave a day or two before using method above.
Good luck, Ellice
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Re: Leaf starch experiment
We use freshly prepared Lugol's Iodine solution, doesn't work if the solution is light or oxidised.
Cheers,
Ana
Cheers,
Ana
Re: Leaf starch experiment
We had good results with mint leaves
- Kathryn
- Posts: 390
- Joined: 01 Jun 2006, 10:00
- Job Title: Lab Technician
- School: Cedars Christian College
- Suburb: Farmborough Hts, Wollongong
- State/Location: NSW
Re: Leaf starch experiment
Me again...
I've just tried doing this again ... made up fresh Lugol's soln, boiled leaves in water, boiled in meths, doused in lugols. The whole leaves just turn really dark brown. It doesn't look very exciting at all. How long do you do each step for? Is there a dramatic difference between the light parts of the leaves and the dark parts?
Thanks for your help...
Kathryn
I've just tried doing this again ... made up fresh Lugol's soln, boiled leaves in water, boiled in meths, doused in lugols. The whole leaves just turn really dark brown. It doesn't look very exciting at all. How long do you do each step for? Is there a dramatic difference between the light parts of the leaves and the dark parts?
Thanks for your help...
Kathryn
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- Posts: 193
- Joined: 27 Jul 2007, 15:29
- Job Title: Lab technician
- School: The Illawarra Grammar School
- Suburb: Figtree
- State/Location: NSW
Re: Leaf starch experiment
I wonder if you're leaving them too long in the metho. We leave only until metho turns green. Have the leaves been in the sun prior to picking? Freshly picked seems to work well.
Re: Leaf starch experiment
We have just done this and it has worked well. The only things I can suggest are leaves need a few hours of sunlight first so don't do it first thing in the morning and rinse the leaf in water before putting it in the iodine solution.
- trish armstrong
- Posts: 224
- Joined: 01 Sep 2008, 07:26
- Job Title: lab Assistant SAO
- School: Taree High School
- Suburb: Taree
- State/Location: NSW
Re: Leaf starch experiment
Hi I need suggestions on an alternate plant than geranium or mint to do this experiment.
One that is varigated would be ideal...
My geranium plants are not varigated and the teachers want varigated, and I can't seem to purchase a plant to suit.
PLEASE HELP!!!
Trish.
One that is varigated would be ideal...
My geranium plants are not varigated and the teachers want varigated, and I can't seem to purchase a plant to suit.
PLEASE HELP!!!
Trish.
Re: Leaf starch experiment
We use hibiscus. Are you too far south for that? What about Spider plants - not the Spider Lilies, but the little house plant.
Cheers, K
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Re: Leaf starch experiment
Variegated Coleus - leaves are green with a white center.
- rae
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- Suburb: Burradoo
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Re: Leaf starch experiment
We have use variegated Hydrangea in the past. May be a problem as they are deciduous.
Re: Leaf starch experiment
We did it today using verigated ivy. It worked like a dream. We boiled it for a while, because leaf has a coating on it and needs to be boiled before immersing in metho. Wash well and flood with iodine.
- trish armstrong
- Posts: 224
- Joined: 01 Sep 2008, 07:26
- Job Title: lab Assistant SAO
- School: Taree High School
- Suburb: Taree
- State/Location: NSW
Re: Leaf starch experiment
Thanks for the suggestions, I'm going plant shopping this arvo and going to try and source some of your suggestions
Thankyou, Trish.
Thankyou, Trish.
Re: Leaf starch experiment
We used the Chinese lantern plant - wonderful!