Lesson #2 Final Project

Title of lesson:  “Organic Compounds”

Source/ Author(s):  Valerie Gibson/ H. Haugen (taken and revised from webpage)

Target Audience: High School Chemistry Students

Lesson plan:

I. Performance or learner outcomes

The student will be able to:

-Use scientific analysis to predict different makeups of the different foods, oils, and juices.

-Discuss organic compounds, and what foods to avoid when a person is on a diet.

II. Overview

During this experiment the students will be able to use different types of chemicals to experiment with a variety of foods, to predict the amount of lipids, proteins, starches, and sugars in those items.

III. Resources, materials and supplies needed

8 test tubes
test-tube rack
lab apron
Benedict's solution
stirring rod
masking tape
plastic gloves
Biuret reagent
test-tube holder
pencil
safety goggles
Lugol's solution
distilled water
newsprint paper
Food substances:

apple juice
melted butter
raw egg white
raw fish
raw potato
raw spinach
vegetable oil

IV. Safety:

*Put on your safety goggles, lab apron, and plastic gloves.

*CAUTION: BenedictÍs solution is poisonous. Do not get any in your mouth and do not swallow any!

* CAUTION: Use a test-tube holder to handle hot test tubes. Point the open end of a test tube away from yourself and others.

*CAUTION: Biuret reagent can burn your skin. Wash off spills and splashes immediately with plenty of water while calling to your teacher.

V. Supplementary materials, handouts.

Table 1: Appearance of Substance after Adding Benedict's Solution

Amount of Sugar in Food	0 none	+ trace	++ little sugar	+++ some sugar	++++ much sugar
Color	blue	blue/green	green	yellow	orange/red

Prediction Table

FOOD	LIPIDS	PROTEINS	STARCH	SUGAR
APPLE	.	.	.	.
BUTTER	.	.	.	.
EGG WHITE	.	.	.	.
FISH	.	.	.	.
POTATO	.	.	.	.
SPINACH	.	.	.	.
VEGETABLE OIL	.	.	.	.
WATER	.	.	.	.

VI. Standards

Texas Essential Knowledge and Skills

Scientific processes. The student, for at least 40% of instructional time, conducts field and laboratory investigations using safe, environmentally appropriate, and ethical practices. The student is expected to:
(A)  demonstrate safe practices during field and laboratory investigations; and
(B)  make wise choices in the use and conservation of resources and the disposal or recycling of materials.

Scientific processes. The student uses scientific methods during field and laboratory investigations. The student is expected to:
(A)  plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting equipment and technology;
(B)  collect data and make measurements with precision;
(C)  organize, analyze, evaluate, make inferences, and predict trends from data; and
(D)  communicate valid conclusions.

Science concept. The student knows that, at all levels of nature, living systems are found within other living systems, each with its own boundary and limits. The student is expected to:
(A)  interpret the functions of systems in organisms including circulatory, digestive, nervous, endocrine, reproductive, integumentary, skeletal, respiratory, muscular, excretory, and immune;
(B)  compare the interrelationships of organ systems to each other and to the body as a whole; and
(C)  analyze and identify characteristics of plant systems and subsystems.

Engagement

Student behaviors / activities	Teacher behaviors / activities
	The foods you eat are made of organic compounds. You can perform chemical tests to learn what foods contain carbohydrates, lipids, and/or proteins.

.

Exploration

Student behaviors / activities

Teacher behaviors / activities

Students will:

1. Read all the directions for this activity before you begin your work.
2. Put on your safety goggles, lab apron, and plastic gloves.
3. Put 8 test tubes in your test-tube rack. Label each test tube by putting masking tape near the top edge of the test tube. Use a pencil to write one of the seven food substances on each label. Mark the eighth label water. The water is your control.

PART I: Testing for Carbohydrates (STARCH)

1. Use a medicine dropper to put ~10 drops of each food in the test tube with the matching label. Add 3-4 drops of Lugol's solution (iodine) to each test tube.
2. Starch is one form of carbohydrate. If the substance in your test tube contains starch, it will turn a blue-black color when it mixes with the iodine solution.
3. Observe the contents of your test tubes and Record the amount of starch present (0, +, ++, +++, ++++) in your data chart. The food which contains the most starch should be recorded as ++++.
4. Empty and wash each test tube and return it to your test tube rack.

PART II: Testing for Carbohydrates (SUGAR)

1. Use a medicine dropper to put ~10 drops of each food into the test tube with the matching label. Add 10 drops of Benedict's solution to each test tube. CAUTION: BenedictÍs solution is poisonous. Do not get any in your mouth and do not swallow any!
2. Use a test-tube holder to carefully place the test tubes in the hot water bath your teacher has prepared. Heat the test tubes for 2 to 3 minutes. CAUTION: Use a test-tube holder to handle hot test tubes. Point the open end of a test tube away from yourself and others.
3. Use a test -tube holder to return the hot test tubes to the test-tube rack. If the substance in your test tube contains sugar, Benedict's solution will change color. See Table 1 below:

Table 1: Appearance of Substance after Adding Benedict's Solution

Amount of Sugar in Food	0 none	+ trace	++ little sugar	+++ some sugar	++++ much sugar
Color	blue	blue/green	Green	yellow	orange/red

4. Observe your test tubes (using white paper as a background). Record the amount of sugar present, in your data table.
5. Empty your test tubes, clean them thoroughly, and return them to the test tube rack.

PART III: TESTING FOR LIPIDS

1. Use a medicine dropper to put ~1 drop of each food onto the newsprint.
2. Observe and compare/contrast the translucence of each food substance. Record the information, in order of translucence (0, +, ++, +++, ++++) in your data chart. The food which contains the most lipids should be recorded as ++++.

PART IV: TESTING FOR PROTEIN

1. Use a medicine dropper to put ~10 drops of each food on the test tube with the matching label. Use a medicine dropper to carefully add 10 drops of Biuret reagent to each test tube. CAUTION: Biuret reagent can burn your skin. Wash off spills and splashes immediately with plenty of water while calling to your teacher.
2. Observe the contents of each test tube (using white paper as a background). If the food contains proteins, it will turn a pinkish purple. Record the amount (0, +, ++, +++, ++++) of protein for each food substance in your data table. The food which contains the most protein should be recorded as ++++.
3. Empty the test tubes and clean them thoroughly. Before leaving the laboratory, clean up all materials and wash your hands thoroughly.

Prediction Table

FOOD	LIPIDS	PROTEINS	STARCH	SUGAR
APPLE	.	.	.	.
BUTTER	.	.	.	.
EGG WHITE	.	.	.	.
FISH	.	.	.	.
POTATO	.	.	.	.
SPINACH	.	.	.	.
VEGETABLE OIL	.	.	.	.
WATER	.	.	.	.

Teacher will make sure that every student has taken the necessary safety procedures.

Teacher will then divide the students into groups of two.

Teacher will have made all the solutions needed for this class before the students enter the classroom.

Teacher will put a color scale on the board, this will help later in the experiment.

Teacher will regulate the amount of Lugol’s solution and Benedict’s solution that a student may have for their experiment.

Explanation

Student behaviors / activities	Teacher behaviors / activities
-Students will make a chart for their findings -One student from each group will write their group’s findings on the board -Students will then compare with the rest of their classmates	-Have students present their findings to the rest of the class on the chalkboard as a group. -Compare findings

Elaboration

Student behaviors / activities	Teacher behaviors / activities
Students will discuss why it is important for the body to have these organic compounds and what would happen if humans did not take in all of them.	Teacher will lead discussion,

Evaluation/Assessment

Student behaviors / activities

Teacher behaviors / activities

Answer the following questions on a separate sheet of paper: Which compound is most common in foods that come from plants? Which compound is most common in foods that come from animals? Does water contain any of the organic compounds you tested? Explain why water was used as the control. If you wanted to reduce the amount of fat in your diet, what foods would you avoid? Which foods tested would your body use for a quick burst of energy? For energy when no carbohydrates are available? For building body parts?

Teacher will hand out these questions and the students will answer before the students will turn in their lab notebook.