Starch in leaves
To demonstrate the presence of starch in vegetable tissues.
Cosa imparano gli studenti
La scienza alla base di questo esperimento
The plant converts carbon dioxide from the air into oxygen and glucose by photosynthesis. Plants store glucose in long molecular chains called starch. Starch is synthesised and stored within chloroplasts and, in most species, is the primary storage form mobilised for translocation during the night.
Attrezzatura utilizzata
- Bruciatore ad alcool — 5514.10
- Tripod stand — 5533.10
- Wire gauze — 5534.25
- Beaker 250 ml — 1118.35
- Beaker 500 ml — 1118.50
- Petri dish — 1253.00
- Pinzette — 8261.30
- Tin foil
- Small plant
Sostanze chimiche e reagenti
- Lugol's solution — R:21-22 S:24/25
- Ethanol — R:11 S:7-16
- Water
Note sulla sicurezza
- Work in a fume cupboard or outdoors.
- Be careful handling the burner and hot glassware.
Domande per gli studenti
- Describe what happens to the leaf during each stage.
- Try to give an explanation.
Cosa aspettarsi
<p>Dipping the leaf in boiling water kills cells and will allow the chemicals to mix. Treating the leaf with alcohol extracts chlorophyll and gives a clearer result.</p><p>Lugol’s solution is a specific iodine reagent that points out the presence of starch turning its colour to blue.</p><p>The leaf part exposed to light made carried out photosynthesis regularly, producing glucose that is stored as starch.</p>
Smaltimento
Dispose of Lugol's solution into the acids and bases waste container.
Prova a fare questo esperimento in classe
Questo esperimento fa parte dell’ATP “ Mobile Lab ” — un laboratorio autonomo che trasforma una normale aula in un vero e proprio laboratorio scientifico, con oltre 200 esperimenti di fisica, chimica, biologia, robotica e ingegneria. “ Gali ”, il tutor basato sull’intelligenza artificiale integrato in ATP Connect, guida gli studenti in ogni fase e risponde alle loro domande direttamente al banco di lavoro.
Vedi il Mobile LabContatta il nostro team