AY Honors/Digestion/Answer Key

Skill Level 2

1. Have the Nutrition Honor.

The answers for the Nutrition honor can be found in the Household Arts chapter of this book.

2. Keep a record of what and how much food you eat for two weeks. Compare your diet to that of the food pyramid.

If you have access to the Internet, you can visit the USDA's MyPyramidTracker.gov web site, the official home of the Food Pyramid. Once you register, you can enter all the foods you eat in a day, and it will analyze your nutrient intake (among other things) based on this information. MyPyramidTracker can retain the information you enter for up to a year, so tracking it for a week will be easy.

If your Pathfinders do not have access to the Internet, have them record their diets on paper. You can then use the website to extract the necessary data by entering each food individually, or you can find a cookbook that has nutrient values of various foods in an appendix. Another option would be to meet in a place that has public Internet access, such as a library or Internet cafe. Then your Pathfinders can enter the data they have collected for a week and analyze it there.

The values in the table below are for children who are physically active for 60 minutes or more per day. Use the USDA website for adults and less active children.

**USDA Food Pyramid**
10 year-old Male	7 oz	3 cups	2 cups	3 cups	6 ounces
Food Group	Grains	Vegetables	Fruits	Milk	Meat & Beans
10 year-old Female	6 oz	2.5 cups	2 cups	3 cups	5.5 ounces
11 year-old Male	7 oz	3 cups	2 cups	3 cups	6 ounces
11 year-old Female	6 oz	2.5 cups	2 cups	3 cups	5.5 ounces
12 year-old Male	8 oz	3 cups	2 cups	3 cups	6.5 ounces
12 year-old Female	7 oz	3 cups	2 cups	3 cups	6 ounces
13 year-old Male	9 oz	3.5 cups	2 cups	3 cups	6.5 ounces
13 year-old Female	7 oz	3 cups	2 cups	3 cups	6 ounces
14 year-old Male	10 oz	3.5 cups	2.5 cups	3 cups	7 ounces
14 year-old Female	8 oz	3 cups	2 cups	3 cups	6.5 ounces
15 year-old Male	10 oz	5 cups	2.5 cups	3 cups	7 ounces
15 year-old Female	8 oz	3 cups	2 cups	3 cups	6.5 ounces

3. What is digestion? What is another name for the human digestive system?

Digestion is the conversion of food into substances that can be absorbed by the body. Another name for the human digestive system is the gastrointestinal tract, or just the GI tract for short.

4. Where does saliva come from? What are the three functions of saliva?

Saliva, often informally known as spit, is the moist, clear, and usually somewhat frothy substance produced in the mouth. Saliva is produced in and secreted from the salivary glands.

Saliva moistens food so it can be swallowed easily.
Saliva contains an enzyme that breaks some starches down into maltose and dextrin.
Saliva protects teeth from decay by plaque. Saliva is used to neutralize acids made from sugars in the mouth, therefore helping to prevent demineralization. Remineralization is when saliva helps repair the damaged crystals of the tooth enamel.

5. Be able to identify the following parts of the tooth. What role do the teeth play in digestion?

Parts of the Tooth

The primary function of teeth is to tear and chew food, reducing it into smaller pieces. This is the first step in the digestive process.

Enamel

Enamel is the outside covering of the exposed portion of a tooth. It is the hardest substance that is part of the human body.

Dentin

Dentin (also called Dentine) is the substance between the enamel (substance in the crown) or cementum (substance in the root) of a tooth and the pulp chamber.

Pulp

The dental pulp is the part in the center of a tooth made up of living soft tissue.

Gum

The gums consist of the tissue surrounding the roots of the teeth and covering the jawbone.

Cementum

Cementum is a specialized bony substance covering the root of a tooth.

Periodontal membrane

The periodontal membrane is the tissue between the tooth and the tooth socket. It holds the tooth in place.

6. Be able to label a diagram or model of all the organs that help with digestion. Starting from where the food goes into the mouth to where is was expelled from the anus.

7. Know the difference between food bolus and chyme.

8. Where does bile come from? Where is it stored? What does it do in the duodenum?

9. What are villi? What makes them absorb the nutrients so quickly? At what point are all the nutrients removed from the food/chyme? Compare the amount of water absorbed by plain paper compared to a similar sized paper towel using an 1/8 cup (17.2 ml) of water.

10. What happens if too much water is present in the large intestine? What happens if not enough water is present?

11. How does fiber in your diet aid in digestion? How long should food remain in the digestive tract? What happens if food stays in the digestive system too long?

12. Demonstrate the digestion of starch into simple sugar using the iodine test.

13. What are the six basic nutrients that are essential for life and where does the bulk of their digestion/absorption take place?

14. Know the difference between monosaccharide, disaccharide, and polysaccharide. What is the most important carbohydrate?

15. What are amino acids? How many are needed to make all the proteins in the body? What is meant by essential amino acids? How many of them are essential? Where can you get all the essential amino acids?

16. What is ATP? What is it used for? What does your body make ATP from? What three sets of chemical reactions make ATP in your body? Why do we need to breathe oxygen?

17. Know the difference between water and fat soluble vitamins. What are two common vitamins that are fat soluble? What are two vitamins that are water soluble?