Question

conducts experiment to test starch? answer please​

Answer 1

Explanation:

Starch Testing Experiment

What You Need:

Two plants

Beaker or glass jar

Saucepan on the stove

Ethyl alcohol

Iodine solution

Tweezers

Test for starch in plants:

Place one of the plants in a dark room for 24 hours; place the other one on a sunny windowsill.

Wait 24 hours.

Fill the beaker or jar with ethyl alcohol.

Place the beaker or jar in a saucepan full of water.

Heat the pan until the ethyl alcohol begins to boil.

Remove from the heat.

Dip each of the leaves in the hot water for 60 seconds, using tweezers.

Drop the leaves in the beaker or jar of ethyl alcohol for two minutes (or until they turn almost white).

Set them each in a shallow dish.

Cover the leaves with some iodine solution and watch.

What Happened:

The hot water kills the leaf and the alcohol breaks down the chlorophyll, taking the green color out of the leaf. When you put iodine on the leaves, one of them will turn blue-black and the other will be a reddish-brown. Iodine is an indicator that turns blue-black in the presence of starch. The leaf that was in the light turns blue-black, which demonstrates that the leaf has been performing photosynthesis and producing starch

Answer 2

Answer:

Objective:

This science project will demonstrate how starches are converted to sugar during mastication and salivation.

Materials:

Plastic gloves

Safety goggles

Tincture of iodine

Water

Eyedropper

Cup

2-3 identical crackers

Several plates or saucers

Cooked potato

Cornstarch

Measuring spoons

Glucose testing strips (e.g., Diastix), optional

Experimental Procedure:

Step 1: Put on your plastic gloves and safety goggles.

Step 2: Mix 10 drops of tincture of iodine with 30 drops of water to make an iodine solution.

Step 3:Put a cracker on a plate, and test it for starch using a drop of the iodine solution.

Step 4:Chew a second cracker for 60 seconds until it is completely mixed with saliva. Spit out the chewed cracker onto another plate, and add a drop of iodine. You may be surprised to observe that the iodine no longer changed colors. The process of chewing the food and mixing it with saliva breaks down the starches in the cracker and converts them into sugars.

Step5:Use this process to test other starchy foods, such as a cooked potato.

Step6:Put two small piles of cornstarch, containing ¼ teaspoon each, on another plate.

Step7:Use the dropper to remove some saliva from your mouth. Put at least ten drops of saliva on one of the cornstarch piles and mix it around.

Step8:Test both piles with the iodine solution.

Step9:If you’d like, you can add a teaspoon of water to each of the above foods and test them for sugar using a glucose stick

Hope it helps.......