NAME ____________________________________
Reading Guide 04 - Biology 160
Am I Really What I Eat?
DUE ____________________
Be prepared to discuss with your group
Read: “Your Digestive System and How It Works,” by the National Digestive Diseases Information
Clearinghouse (NDDIC) http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/#food
What you will learn in this reading guide: What happens to the biological molecules that make up our food’s
cellular structures once we eat them.
1) In your own words, why is digestion important?
2) Draw a diagram of the human digestive system from mouth to anus and label the following parts:
mouth
small intestine
anus
esophagus
large intestine (colon)
stomach
rectum
3) During digestion, carbohydrates are broken down into….
4) During digestion, proteins are broken down into….
5) During digestion, fats are broken down into….
6) Give it your best guess: During digestion nucleic acids are broken down into…
CS, NSCC Biol 160, Nov 2011
7) Think Back: When large molecules like polymers are broken down into smaller molecules like monomers,
what is that chemical reaction called?
8) Think Back: When small molecules like monomers are attached together into large molecules like polymers,
what is that chemical reaction called?
9) Critical Thinking: On a separate sheet of paper, sketch out your ideas of how you think one of the food
items on your group’s menu starts as food and eventually is used by your cells. Be sure to include cellular
structures, water and large biological molecules, pH, enzymes, covalent bonds, hydrogen bonds, hydrolysis, and
dehydration reactions.
Here’s a suggestion of how to start:
Your specific food item (example: potato)  has this type of cells (example: plant cells)  with these cellular
structures (example: amyloplasts)  that are made of or contain these large biological molecules (example:
starch)  when we eat this food we chew it up and enzymes and water in our saliva begin to break the covalent
bonds of the starch polymer into monosaccharide monomers through hydrolysis  we swallow it into our
stomach….
…Keep filling in the missing information…
… the monomers are circulated through the blood to all of our cells  where our cells take up the monomers
and, through dehydration reactions build glycogen polymers for energy storage.
Make sure you can do this for each of the 4 types of large biological molecules. Have fun!
CS, NSCC Biol 160, Nov 2011