Download HomeworkCh_15,16Answers

Chapters 15 and 16
1. Plants do not eat but do require CO2, H2O, and sunlight to live. How is this different
from animals? What system do plants have to allow for their simple needs?
Animals require nutrients such as carbohydrates, proteins and lipids to survive.
Photosynthesis.
2. What substances constitute the macronutrients? The micronutrients?
Macronutrients: carbohydrates, proteins, lipids
Micronutrients: vitamins, minerals
3. All 20 amino acids are essential to build new proteins. Why are only a few amino
acids called essential?
Because they can not be synthesized by the body and must come from the diet.
4. Why are plant oils usually liquids and animal fats usually solid?
Plant oils are unsaturated fats (contain double bonds) while animal fats are saturated
(no double bonds).
5. Explain the French paradox.
Grapes and wine contain a natural antidote, resveratrol, to MI and cancer, scientists
report. This discovery could help explain the so-called “French paradox’ - the lower
rates of heart disease and cancer in nations such as France, Italy, Spain.
6. What are some strategies that can be used to increase HDL levels?
A diet low in saturated fats and cholesterol.
7. Which vitamins must be consumed on a regular basis, and why?
The water soluble vitamins which can be depleted via urinary excretion in as little as two
weeks. See Table of water soluble vitamins in the ppt lecture on “Nutrition”.
8. A typical diet in the United States provides 20% of the calories from protein, 55%
from carbohydrates, and 25% from fats. Calculate the grams of protein, carbohydrate,
and fat to be included each day in diets having the following caloric requirements.
a. 1600 kcal
Proteins:320kcal x 1g/4kcal = 80g
Carbohydrates:880kcal x 1g/4kcal = 220g
Fats:400kcal x 1g/9kcal = 44g
b. 2300 kcal
Proteins:460kcal x 1g/4kcal = 115g
Carbohydrates:1265kcal x 1g/4kcal = 316g
Fats:575kcal x 1g/9kcal = 64g
c. 1900 kcal
Proteins:380kcal x 1g/4kcal = 95g
Carbohydrates:1045kcal x 1g/4kcal = 261g
Fats:475kcal x 1g/9kcal = 53g