Grade Level: High School; Type: Biology
This science project examines the different composition of fungi and plants.
- How are fungi different from green plants?
- What is the difference between sugar and starch?
- What is a chemical indicator?
- What happens when Benedict’s solution reacts with sugar?
- What happens when iodine reacts with starch?
- Store-bought mushrooms
- Iodine (available from drug store or scientific supply outlet)
- Measuring spoon or graduated cylinder
- Benedict’s solution (available from scientific supply outlet)
- Paring knife
- Kitchen stove
- Small saucepan for heating mushrooms
- Green leaves
- White sugar
Procedure for Experiment #1
- Slice the mushroom lengthwise.
- Using an eyedropper place eight to ten drops of iodine on the interior surface of the mushroom.
- Write down your observation. Do you think there was more starch or sugar in the mushrooms?
Procedure for Experiment #2
- Put a half cup of water into a saucepan. Add one tbsp. of sugar and one tbsp of Benedict’s solution and stir.
- Heat to a low simmer.
- Carefully pour the hot water into a two-cup measuring cup. Did you observe any changes in color? Record your observations.
Procedure for Experiment #3
- Dice four or five small mushrooms into very small pieces.
- Put the mushrooms in a small saucepan. Add three-fourths cup water and 20 ml (approximately 1.5 tablespoons) Benedict’s solution to the saucepan
- Bring the mushrooms to a simmer. Continue simmering for five minutes.
- Turn off the stove. Decant the water into a clear glass measuring cup. Was there a color change? Write down your observations. What do you deduce from what you observed?
Procedure for Experiment #4
Repeat experiment #4, using eight to ten green leaves instead of mushrooms. The leaves should be collected first thing in the morning, and the experiment should be performed immediately thereafter. Using a scissor, cut the leaves in small pieces about a centimeter wide before covering them with water.
Terms/Concepts: sugar, starch; why green plants have sugar and fungi doesn’t; chemical indicator
References: "Benedict's Solution, a Reagent for Measuring Reducing Sugars: the Clinical Chemistry of Stanley R. Benedict," Journal of Biological Chemistry, April 19, 2002 Plant Physiology Online, Lincoln Taiz and Eduardo Zeiger