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Chapter 6 REVIEW Answer Key for Group Responses
March 26, 2014
True/False Questions
1) Once DNA leaves the nucleus, its mRNA copies are made and brought to the ribosome.
Answer: FALSE
2) Plant proteins may be less digestible, especially when eaten raw. Answer: TRUE
3) Hemoglobin acts as a transport protein that carries nitrogen to cells from the lungs.
Answer: FALSE
4) Whole-wheat bread contains complete proteins. Answer: FALSE
5) Proteins within the body help to maintain fluid balance but not acid-base balance.
Answer: FALSE
6) During periods of starvation, the carbon skeletons of the amino acids are used for energy and
for gluconeogenesis. Answer: TRUE
7) People with marasmus are starving. Answer: TRUE
8) Children with kwashiorkor are prone to infections. Answer: TRUE
9) A protein is considered a complete protein if it contains all 11 nonessential amino acids and
some of the 9 essential amino acids. Answer: FALSE
10) Numerous research studies have shown that bones lose calcium when a person's diet is too
high in protein. TRUE
11) Vitamin A is found only in animal foods, but vegetarians can meet their needs by consuming
its precursor, beta-carotene. Answer: TRUE
12) A typical healthy adult is normally in a state of positive nitrogen balance. Answer: FALSE
13) The absorption of zinc is inhibited by animal protein. Answer: FALSE
14) A high-protein diet has been linked to a lower risk of heart disease. Answer: FALSE
15) Consuming too much of any one amino acid via supplements can impede absorption of other
amino acids in the intestinal tract. Answer: TRUE
16) Vegetarians can only consume adequate protein by eating a variety of vegetables and fish.
Answer: FALSE
17) The element found in protein but not carbohydrate is oxygen. Answer: FALSE
18) Nonessential amino acids can become essential if the body cannot make them, such as during
Nutrition & the Human Body
Chapter 6 REVIEW Answer Key for Group Responses
March 26, 2014
bouts of illness. Answer: TRUE
19) When amino acids are broken down, they lose their amine groups. Answer: TRUE
20) Isoflavones are weak plant estrogens. Answer: TRUE
True or False
1.
Your body can make all the protein it needs. TRUE
2. Proteins provide structural support. TRUE
3. Most enzymes are proteins. TRUE
4. Your body can use protein as an energy sources. TRUE
5. Growing children are in a stated of negative nitrogen balances. FALSE
6. You can digest the protein in pasta as easily as the protein in a chicken breast. FALSE
7. Approximately one-half of your daily calories should come from protein. FALSE
8. Active people need to eat protein bars. FALSE
9. Eating too much protein-rich food may increase your blood cholesterol level. TRUE
10. Soy is a good source of dietary protein. TRUE
Short Answer Questions
1) What is the difference between an incomplete protein and complete protein? Give an example
of each.
Answer: An incomplete protein is a protein that is low in one or more of the
essential amino acids—beans, for example. A complete protein is a protein
that provides all nine of the essential amino acids, along with some of the
11 nonessential amino acids. Chicken is a complete protein.
Page Ref: 196
2) Describe the basic structure of an amino acid.
Answer: Amino acids contain an amine group (NH2), a carboxyl group
(COOH), a central carbon atom (C), a hydrogen atom (H), and a variable
side group (20 different). The side group is the part that provides the
amino acid with its unique qualities.
Page Ref: 183
3) What would you say to someone who purchases protein bars regularly?
Answer: Most people consume excess protein from foods, since protein is
found in all foods except fruit. Extra protein is not used to build muscle
Nutrition & the Human Body
Chapter 6 REVIEW Answer Key for Group Responses
March 26, 2014
but is, rather, converted to fat. Also, protein bars are expensive when
compared to regular food, and they often are high in sugar.
Page Ref: 202-203, 219
4) What is the difference between an essential and a nonessential amino acid?
Answer: An essential amino acid must be consumed in the diet because
the body cannot make it. A nonessential amino acid could be made by
the liver from an essential amino acid present in the diet.
Page Ref: 184
5) Why might a vegetarian diet also be a lower-calorie diet than a diet that includes meat and
dairy?
Answer: A plant-based diet that contains mostly fiber-rich whole grains
and low-calorie, nutrient-dense vegetables and fruits tends to be one
that "fills you up before it fills you out," which means that you are
likely to eat fewer overall calories.
Page Ref: 209
What are the potential risks and benefits of a vegetarian diet? Page Ref: 209
Answer: The benefits of a vegetarian diet are that it is low in fat, especially
saturated fat and cholesterol, and high in fiber-rich plant foods that contain
beneficial phytochemicals. This diet has been shown to reduce the risk of
heart disease, high blood pressure, diabetes, cancer, stroke, and obesity. The
risks of a vegetarian diet include under-consumption of certain nutrients, such
as protein, vitamin B12, iron, zinc, calcium, vitamin D, riboflavin, vitamin A,
and omega-3 fatty acids.
Nutrition & the Human Body