GRADE: Seventh

CONTENT STANDARD: Life Science

CONTENT TOPIC: Living Systems

CONCEPT: The human body is dependent upon good nutrition.

CONTENT OBJECTIVE: 7D4.00 To understand the factors that are basic to good nutrition

INSTRUCTIONAL OBJECTIVE: The learner will:

4.01 define nutrition and nutrients.
4.02 describe 2 reasons why a person needs food.
4.03 list the 6 major groups of nutrients.
4.04 identify the 4 basic food groups.
4.05 match nutrient with food groups.
4.06 determine the approximate number of calories needed by a person.
4.07 learn the importance of energy.
4.08 recognize the effects of improper nutrition.

Listening, taking notes, researching, using library, making observations, recording observations, drawing conclusions

I. Define
A. Nutrition
B. Nutrients
II. Major classes of nutrients
A. Nutrients and their major function
1. Water
2. Vitamins
3. Minerals
4. Proteins
5. Carbohydrates
6. Fats
B. Food sources for each nutrient
III. Four Basic Food Groups
A. List the groups with type of food
1. Dairy
2. Meat
3. Grains
4. Fruit-Vegetable
B. Match nutrients with food groups
IV. Nutrition and Energy
A. Measuring energy value
1. Calories
2. Amount needed
B. Factors affecting amount of energy needed
1. Age
2. Size
3. Amount of activity
V. Effects of Improper Nutrition
A. Under-nutrition
B. Malnutrition
1. Lack of protein
2. Lack of vitamins
3. Lack of minerals
4. Lack of water
C. List of many other ways body is affected

TN COMPONENT OF SCIENCE: Science in Society

TN GOAL:

To enable students to demonstrate positive attitudes toward science in solving problems and making personal decisions about issues affecting the individual, society and the environment.

4.6 POLITICS - Basic scientific concepts should be available to all individuals enabling each to make logical decisions for themselves and others.

4.6a Scientific literacy influences the political process.

BENCHMARK:A scientifically literate society may lend support to research and development through the political process.

TIME REQUIRED:

Approximately 5 teaching periods, depending on amount of active participation

Chalkboard or overhead projector, chart to be completed by students, cooked egg white, nitric acid, iodine, brown paper, indophenol solution, potato, cracker, margarine, peanut butter, apple juice, orange juice, chart of food and amount of calories

Amino acids, calorie, energy, glucose, nutrient, nutrition

Have you ever skipped a meal? (response) Then you know what it is like to be hungry. How does it feel to be hungry? (response) This is your body's way of telling you that you need food. We need food for two reasons:

1. The materials that it contains

2. For energy

We will find out what these materials are and why we need energy.

The study of food and how your body uses it is called nutrition. For the next several days we will be studying nutrition to find out the kinds of food we need and why we need these foods.

The materials our body needs in order to be healthy are called nutrients. There are six major groups of nutrients that are present in foods - water, vitamins, minerals, protein, carbohydrates, and fats. These nutrients are needed for proper growth, maintaining body activities, repairing tissues, and also for energy.

Eating the right combination of foods will provide our body with these nutrients. This is called eating a balanced diet.

Lets take each nutrient and find out why each is important for our body. (Use table for students to complete as each nutrient is discussed. Either give each a copy or have the students make their own.)

1. Water - Our bodies contain about 60-70% water. This means that if you weight 100 pounds, about 60-70 lbs. would be water. This lets us know how important water is to our body and that we need to carry it to the body cells. Water makes it possible for your body to remove wastes. For example, the kidneys form urine which is mainly water containing dissolved wastes. Sweat is also water with dissolved wastes. Sweat also helps the body to maintain the proper temperature. Water is also needed for many chemical changes that occur in the body. The liquid part of the blood is about 90% water.

2. Vitamins are nutrients that are needed in tiny amounts. Some vitamins can be stored by the body while others must be supplied to the body on a regular basis. One vitamin can be made by the skin. Some of the better know vitamins are : A, B-complex, C, D, E, and K.

Vitamins are needed for normal growth and for body activities. They are needed to prevent certain diseases.

Fruits and vegetables are good sources of vitamins.

Test for Vitamin C

A. Pour 5 ml of indophenol solution into 4 labeled test tubes.

B. Add apple juice drop by drop to the first test tube until the indophenol loses all its color. Record the number of drops.

C. Add orange juice drop by drop to the second test tube until the indophenol loses its color. Record the number of drops.

D. Add lemon juice to the third test tube, drop by drop, until the indophenol loses its color. Record the number of drops.

E. Indophenol is a blue liquid that turns colorless when Vitamin C is present. The more vitamin C there is in a juice the less juice it will take to turn indophenol colorless. Which has the most vitamin C?

3. Minerals are vital to the body in many ways. Many must be in compound form before being eaten because the chemically pure elements such as sodium or chlorine would be fatal. When these two elements are in a chemical compound form, (Sodium chloride commonly know as table salt) they are not fatal.

Many minerals such as calcium, magnesium, phosphorus and potassium are needed in relatively large quantities on a daily basis. Others such as iron, manganese, and iodine are needed in smaller amounts. Still others are needed in such small amounts they are called trace elements. Some of these are copper, zinc, and cobalt.

Each mineral is used by the body for a special purpose. Calcium, a well-known mineral, is needed for strong bones and teeth, and is also needed for proper blood clotting. Iron is needed for the production of red blood cells. Iodine is required by the thyroid gland. Many are used to make enzymes and other important substances.

Vegetables, fruits, milk, eggs, cereals, and fish are good sources of minerals.

The next three nutrients we will discuss are called organic nutrients because they all contain the element, carbon. They also contain oxygen and hydrogen.

4. Proteins are made of organic compounds called amino acids. In addition to carbon, hydrogen, and oxygen, proteins contain nitrogen. Some contain sulfur or phosphorus.

There are more than 20 amino acids needed by the body. All but about eight amino acids can be synthesized by the body, and we must get these from different foods. Foods from animals contain these eight essential amino acids. Meats, as well as eggs, mild and cheese, are then a good source of protein. These are said to be complete sources of protein.

Proteins from plants are incomplete so one must have a variety of plants in order to obtain the eight different amino acids. The amino acids are very important to remember if a person is a vegetarian.

Amino acids are needed by the body for growth and repair of the body tissues, to make hormones, enzymes, and antibodies. Proteins can also supply energy. Test for Proteins

A. Put a small piece of cooked egg white in a test tube.

B. Add a few drops of nitric acid to the test tube (be careful not to get on skin).

C. Heat test tube gently.

D. The yellow color shows that the food contains protein.

5. Carbohydrates contain the tree elements carbon, hydrogen, and oxygen. All carbohydrates are changed to a sugar called glucose when digested. Glucose is used by the body cells to produce energy for life activities. Carbohydrates also supply cells with materials needed to build cell structures. They can be stored as suppliers of reserve energy.
A. Put a drop of iodine on each - bread, potato, and cracker

B. Iodine turns from brownish-red to blue-black in the presence of a starch

6. Fats and oils are very important sources of energy. Fats contain twice as much energy as an equal amount of carbohydrates. Fats are solids at room temperature while oils are liquids.

Fats are needed as solvents for certain vitamins. Fats provide insulation and protection for body organs. Stored fat is usually found under the skin and around the organs. Fats are also made of the elements carbon, hydrogen, and oxygen.

Fats are found in cheese, milk, butter, and nuts. Also fats are found in animal foods

Test To See What Foods Contain Fats and Oils

A. Hold a piece of brown paper toward light. Does light pass through the paper? (No)

B. Rub a small amount of butter or margarine on the paper. Allow it to dry.

C. Hold the paper toward the light. Does light pass through the paper? (Yes) (You can try this with other foods - potato, peanut butter, etc. to see if they contain fat.)

1. Students will complete this table during the discussion.

Nutrient Major Food Function Sources

1.

2.

3.

4.

5.

6.

2. Have students bring labels from food containers showing the nutrients and their amounts. Each student can share this information.

Match the terms with the correct definition. Some terms may be used more than once.
A. Nutrition ___________ 1. Contain a large amount of energy.

B. Nutrient ___________ 2. Kinds of carbohydrates

C. Sugar & Starch ___________ 3. The study of food and how the body uses it.

D. Protein ___________ 4. Compound which makes up about 60-70% of body mass.

E. Fats & Oil ___________ 5. Nutrient which contains nitrogen.

F. Vitamins ___________ 6. Nutrient needed in small amounts.

G. Water ___________ 7. Nutrient that must be in compound form before being eaten.

H. Minerals ___________ 8. Carbohydrates are broken down into this by digestion.

I. Glucose ___________ 9. Nutrient made of amino acids.

___________ 10. Material in food needed by the body.

We have discussed the importance of the materials in food that we need. Write down two reasons why we need food. (pause) Also we learned there are six important nutrients in food. Write down the names of these six nutrients and compare with your neighbor.

1. Students can choose specific vitamins to research. Describe their discovery and what they do for the body

2. Have students locate minerals on a periodic table.

This classroom connector addresses instructional objectives 2.04 and 2.05.

We eat food every day. How can we know if we are getting the nutrients we need? (Balanced Diet)

We can be sure we are getting all the nutrients if we eat a supply of different foods. We can put the food into 4 large groups. These are known as the four basic food groups. They are:

1. Fruits & Vegetables are the green, yellow and orange vegetable, citrus and other fruits.

2. Grains include the cereals, bread and spaghetti.

3. Meat group includes fish, eggs, pork, beef, poultry, nuts and dried beans.

4. Milk group includes milk products, ice cream, cheese and yogurt.

Other foods may compliment these foods, but they will not replace the goods. Examples are catsup, salad dressing, mustard, jam, jellies, etc. Which nutrients would fit into each food group?

1. Fruits & Vegetables-vitamins, minerals, water

2. Milk - vitamins, minerals, fat, water

3. Meat - protein, fats, minerals

4. Grains - carbohydrates, vitamins, minerals

(Try the following activities:

1. Have students list all the foods they have eaten in the last three days. Classify the foods into the four basic good groups. They should observe whether or not they are getting a healthy variety of food.

2. Have students plan a menu for three days, making sure each meal consist of food from the four basic food groups.)

We have learned that we need a balanced diet in order to get all the nutrients our bodies need in order to stay healthy. Take a sheet of paper and write the names of the basic groups.

This classroom connector addresses instructional objectives 2.06 and 2.07.

Food we eat not only supplies our body with necessary nutrients, it also gives us energy. What is energy? (Ability to do work) Why do we need energy? (To move, for body activities such as circulation, digestion, respiration, etc.) Which nutrients can give us energy? (Proteins, carbohydrates and fats) Which contains the most energy? (Fats)

We will learn how to measure and determine the amount of energy we need.

The energy in our food is measured in units called calories. A calorie is the amount of heat needed to raise one kilogram of water 1 degree Celsius. The number of calories needed depends on how much energy a person uses. Knowing how much you should eat is just as important as knowing what to eat. Different kinds of foods provide different amounts of energy.

The amount of energy a person needs depends mainly on three factors:

1. their age

2. body size

3. how active the person is

A young person needs more energy than an adult because a young person needs extra energy while growing. Recommended daily energy needs are:

Male (ages 11-14) -2800 calories

Female (ages 11-14) -2400 calories

A large person needs more energy than a small one. The more active you are the more energy you need. Do you think sitting in class taking notes requires more energy than exercising in gym class? (No, exercising would require the most.)

What happens when a person regularly takes in more calories than are used up each day? (Gains weight) Excess food energy is stored in the body as fat causing a person to gain weight. If a person consumes fewer calories than needed the stored fat will be broken down and used. How will this effect a person weight? (Lose weight)

(Try the following:

1. Show food with calories content: Ask students to write answers to the following questions.

A. Which types of food have the fewest calories? (Fruit & vegetables)

B. Which types of food have the highest calories content? (Seeds)

C. Which would be the best choice for snacks especially if one is concerned about weight gain? (Apple, banana, carrot, etc.)

2. Complete a personal study of your eating habits.
A. List foods eaten for one day (or one week)

B. Estimate the number of calories. (Students may need reference books with list of food and calories. This could be library work.)

C. Students need to assess if they are getting enough calories.)

We have learned how energy is measured and the factors that determine how much energy we need. What unit is used to measure energy? (Calories) What three things affect how much energy we need? (Age, size, activity) How can our calorie intake affect our weight? (Too many - overweight; too few - underweight; equal - maintain weight.)

(1. Have students investigate and report how the energy value of food is determined[Bomb calorimeter]

Food Number of calories

apple (raw) 70

banana (raw) 85

beans (green - 1 cup) 25

bread, white (1 slice) 60

broccoli (1 cup) 45

cabbage (1 cup) 40

candy bar (chocolate)` 250

carrot (raw) 45

cheese, American (1 slice) 115

chicken, boiled 115

coke drink 100

corn (1 ear boiled) 70

doughnut 240

egg (whole) 80

hot dog 155

hamburger sandwich 350

ice cream 160

milk (1 cup) 165

peas (1 cup) 110

peanuts (1 cup) 840

pizza (cheese - 1 slice) 170

potato chips (10) 110

taco 160

tomato (1) 40

tuna fish 170

yogurt (1 cup) 225

This classroom connector addresses instructional objective 2.08.

We have learned what kinds of food we need and the amounts that we need. What will happen to us if our diets do not contain these nutrients? (We will not grow properly, will be sick, etc.)

An adult can go without food for several weeks and recover easily with no ill effects. A growing child that is starved or under nourished for any length of time may suffer life-long disabilities. If a child doesn't get enough food he literally wastes away. Bones become prominent and the child will begin to look like an old person. The child will have no energy because of the lack of calories from the food.

In the U.S. today, starvation or suffering from under nutrition is not the major problem. Our major nutrition problem is not enough of the right kinds of food nutrients. Let's briefly consider a few examples of how a lack of specific nutrients will affect our body.

1. Protein - what are the main sources of protein? (Meat, eggs, & fish) In some parts of the world the diet lacks these foods. The people develop a sickness called kwashiorkor because of a lack of protein. The children look like those who are starving - they lose weight and growth is not normal.

2. Vitamins - There are many vitamins which the body needs for many different reasons. Sickness from a lack of vitamins is called a deficiency disease. Scurvy is one example of a deficiency disease. This is caused by a lack of Vitamin C. A symptom of scurvy is red spots under the skin where blood has leaked out. Also the gums bleed easily. A person can recover very quickly from this disease once he begins to get Vitamin C.

Another deficiency disease is pellagra which is caused by a lack of niacin. In this disease the skin becomes hard and scaly, the mouth become sore, and the person becomes weak. If it lasts long enough one may begin to act as if he were insane. Again if this is added to the diet the person will recover.

There are other deficiency diseases and many other ways our bodies will be affected if we do not have enough vitamins of the right kind in our diets.

3. Minerals comprise a group of nutrients of which we need a variety. Many foods contain minerals.

We will consider a few of the many minerals we need:

a. Calcium is the main ingredient of our bones. It is also needed for proper clotting of he blood when we bleed. Calcium is also needed by the nerves. How would we be affected without calcium? (Our bones would become weak, our blood might not clot quickly enough, heart would not beat regularly.)

b. Iron is the mineral that makes or blood red. Without iron, our body could not make red blood cells that carry oxygen to our body. How would we feel if we did not get enough oxygen? (Weak) Why? (We would not be getting enough energy.) This illness is called Anemia.

c. Iodine is another mineral. It is needed by the thyroid gland which is located in the neck. Iodine is used by the thyroid gland to control the speed of chemical reactions in our body. A disease called goiter occurs when there is a lack of iodine. The thyroid gland swells in the throat to about the size of a baseball. Do you know where we get most of our iodine? (It comes from iodized salt.) We rarely see people with this disease today because most people get salt that has had iodine added to it.

d. Water - Man can live a long time without food - 70-80 days, but he is lucky if he can stay alive even three days without water. Without water a person stops perspiring, can no longer urinate so poisons build up in the body causing death. When the body loses fluids faster than they are replaced, we say that dehydration is occurring. This is a very serious illness Just think about how much of our body is really water The cells contain water, so does our blood, saliva, lymph, and other fluids. This is why water is so important.

Malnutrition results in the body's inability to function correctly. Here are some more ways our body will be affected - poor development, flabby muscles, too little or too much weight for our height, too little or too much fat under the skin, pale-rough skin, poor posture, decayed teeth, poor tongue and mouth color with frequent mouth sores, rough-thin hair that tends to fall out easily, dulled senses of taste and smell, inability to concentrate, more susceptibility to infections, irritability, poor appetite and the list goes on.

1. (Student- should give written and/or oral report- on other illness related to lack of specific nutrition).

2. If possible, find a missionary who has traveled to undernourished areas to talk about the conditions, diseases, etc.

3. Have a nurse or doctor come in to talk about nutrition and its impact on health.

We have learned why proper nutrition is so important to our health. Write down five things that can happen to us if we do not get the necessary nutrients. Can you tell the difference between malnutrition and undernourished? (response) Describe each on your paper. (pause, then review answers)

(Invite a nutritionist, or nurse to speak to class about nutrition.)

Penelope H. Bauer, Michael A. Magnoli, Armand Aleverey, Dorothy Chang-Van Horn, Delilah T. Gomes. Experiences in Biology. Laidlow Brothers Publishers, 1985.
Charles H. Heimler. Focus On Life Science. Charles E. Merrill Publishing Company, 1984.
Paul Humner Jr., Albert Kaskel, James E. Kennedy, Raymond F. Oram. Probing Levels of Life, A Laboratory Manual. Charles E. Merrill, 1979.

amino acids - organic compounds which make proteins

calorie - unit used to measure energy in food, the amount of heat needed to raise one kilogram of water one degree Celsius

energy - the ability to do work

glucose - a simple sugar formed when carbohydrates are digested

nutrient - materials needed by the body in order for it to be healthy

nutrition - the study of food and how the body uses it

This is the time this file has been accessed since 04/02/98.

The University of Tennessee at Martin is not responsible for the information or views expressed here.

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