STUDY QUESTIONS
CHAPTER 9-12
**NOTE: I have included the answers to the study questions since I am posting them so close to
the exam dates. Be sure you understand the role of the hormones ADH, renin, angiotensin and
aldosterone in the regulation of fluid balance.
CHAPTER 9
1.
Describe how body fat develops and suggest some reasons why it is difficult for an obese
person to maintain weight loss.
Body fat develops when fat cells increase in number and size. Prevention of excess weight gain
depends on maintaining a reasonable number of fat cells; when an obese person loses weight, the
body attempts to return to the original weight, or its set point.
2.
What factors contribute to obesity?
Genetics (leptin, ghrelin, uncoupling problems, fat cell metabolism), overeating, inactivity.
3.
List several aggressive ways to lose weight and explain why such methods are not
recommended for every overweight person.
Fad diets, diuretics, amphetamines, other prescription drugs, over-the-counter drugs, hot baths,
machines that jiggle, brushes, sponges, massages, surgery, gastric partitioning, gastric balloons,
jaw wiring, very-low-kcalorie diets. Reasons these are not recommended: weight cycling,
psychology of weight cycling, some methods do not work at all, others only provide temporary
weight loss (not fat loss).
4.
Discuss reasonable dietary strategies for achieving and maintaining a healthy body
weight.
Eating plans based on realistic energy intake, nutritional adequacy, physical activity, making
small behavior modification changes, support groups.
5.
What are the benefits of increased physical activity in a weight-loss program?
Physical activity increases BMR, helps control appetite, provides psychological benefits.
6.
Describe the behavioral strategies recommended for changing an individual’s dietary
habits. What role does personal attitude play?
See Table 9-4, Weight-Management Strategies; a personal attitude of sound emotional health
supports positive behavior change.
7.
Describe strategies for successful weight gain.
Eat energy-dense foods to provide excess of 700-1000 kcals per day, eat regular meals daily, eat
large portions, eat extra snacks between meals, drink plenty of juice and milk, exercise to build
muscle.
CHAPTER 10
1.
How do the vitamins differ from the energy nutrients?
They differ in structure, function, and food contents.
2.
Describe some general differences between fat-soluble and water-soluble vitamins.
Water-soluble vitamins are: carried in the blood, excreted in the urine, needed in frequent, small
doses, unlikely to reach toxic levels in the body. Fat-soluble vitamins are: absorbed into the
lymph and carried in the blood by protein carriers, stored in body fat, needed in periodic doses,
and more likely to be toxic when consumed in excess of needs.
3.
Which B vitamins are involved in energy metabolism? Protein metabolism? Cell
division?
B vitamins involved in energy metabolism: thiamin, riboflavin, niacin, biotin, pantothenic acid. B
vitamin involved in protein metabolism: vitamin B6. B vitamins involved in cell division: folate
and vitamin B12.
4.
For thiamin, riboflavin, niacin, biotin, pantothenic acid, vitamin B 6, folate, vitamin B12,
and vitamin C, state:



Its chief function in the body.
Its characteristic deficiency symptoms.
Its significant food sources.
See respective summary tables for each nutrient in the text.
5.
What is the relationship of tryptophan to niacin?
Tryptophan can be converted to niacin in the body: 60 mg tryptophan = 1 mg niacin.
6.
Describe the relationship between folate and vitamin B 12.
Vitamin B12’s and folate’s roles intertwine because each depends on the other for activation.
Folate is part of a coenzyme that helps convert vitamin B 12 to one of its coenzyme forms and helps
synthesize DNA; vitamin B12 removes a methyl group to activate the folate coenzyme.
7.
What risks are associated with high doses of niacin? Vitamin B 6? Vitamin C?
Niacin: diarrhea, heartburn, nausea, ulcer irritation, vomiting, fainting, dizziness, painful flush
and rash, excessive sweating, liver damage, low blood pressure. Vitamin B 6: depression, fatigue,
headaches, nerve damage, muscle weakness, numbness, bone pain. Vitamin C: nausea,
abdominal cramps, diarrhea, false results in diabetes tests, interference in drug effectiveness,
hemolytic anemia, stone formation, rebound scurvy.
CHAPTER 11
1.
List the fat-soluble vitamins. What characteristics do they have in common? How do they
differ from the water-soluble vitamins?
Vitamins A, D, E, and K. Found in the fat and oily parts of foods; stored primarily in the liver and
adipose tissue. Fat-soluble vitamins are stored longer; therefore, daily intake is less crucial and
toxicity risk is greater than for water-soluble vitamins.
2.
Summarize the roles of vitamin A and the symptoms of its deficiency.
Vitamin A is important in vision; maintenance of cornea, epithelial cells, mucous membranes,
skin; bone and tooth growth; reproduction; hormone synthesis and regulation; immunity; cancer
protection. Symptoms of deficiency include anemia, diarrhea, general discomfort, depression,
frequent respiratory, digestive, bladder, vaginal and other infections, abnormal tooth and jaw
alignment, night blindness, keratinization, corneal degeneration leading to blindness, rashes.
3.
What is meant by vitamin precursors? Name the precursors of vitamin A, and tell in
what classes of foods they are located. Give examples of foods with high vitamin A
activity.
Compounds that can be converted into the active form of a vitamin. Carotenoids (the most active
being beta-carotene) are available from plant foods; retinol compounds are available from animal
foods. Examples of high vitamin A activity are: eye activity from light to dark, bone growth.
4.
How is vitamin D unique among the vitamins? What is its chief function? What are the
richest sources of this vitamin?
With sunlight, vitamin D can be made from cholesterol. Its chief function is to promote
mineralization of bones. Richest sources are fortified milk, fortified margarine, eggs, liver, fatty
fish.
5.
Describe vitamin E's role as an antioxidant. What are the chief symptoms of vitamin E
deficiency?
Vitamin E protects other substances from oxidation by being oxidized itself; it protects the lipids
and other vulnerable components of the cell and its membranes from destruction. It is especially
effective in preventing the oxidation of the polyunsaturated fatty acids. Deficiency symptoms
include red blood cell breakage and anemia.
6.
What is vitamin K's primary role in the body? What conditions may lead to vitamin K
deficiency?
Synthesis of blood-clotting proteins and a blood protein that regulates blood calcium. Conditions
which can lead to vitamin K deficiency are taking of antibiotics or sulfa drugs and consuming a
diet low in vitamin K.
CHAPTER 12
1.
List the roles of water in the body.
Water carries nutrients and waste products throughout the body; helps to form the structure of
macromolecules; actively participates in chemical reactions; fills the cells and the spaces between
them; serves as the solvent for minerals, vitamins, amino acids, glucose, and many other small
molecules; acts as lubricant around joints; serves as shock absorber inside the eyes, spinal cord,
and in pregnancy, the amniotic sac; aids in the body's temperature regulation.
2.
List the sources of water intake and routes of water excretion.
Sources of intake: liquids, foods, metabolic water. Routes of excretion: kidneys, skin, lungs,
feces.
3.
What is ADH? Where does it exert its action? What is aldosterone? How does it work?
ADH is a hormone released by the pituitary gland in response to highly concentrated blood. It
exerts its action on the kidneys, and they respond by reabsorbing water, thus preventing water
loss. Aldosterone is a hormone secreted by the adrenal glands that stimulates the reabsorption of
sodium by the kidneys.
4.
How does the body use electrolytes to regulate fluid balance?
The body uses electrolytes to control the movement of water inside cells and between cells.
5.
What do the terms major and trace mean when describing the minerals in the body?
Major minerals are needed in the largest amounts in the body; trace minerals are needed in small
amounts in the body. Both are equally important.
6.
Describe some characteristics of minerals that distinguish them from vitamins.
Minerals can become charged particles and can form compounds; minerals retain their chemical
identity.
7.
What is the major function of sodium in the body? Describe how the kidneys regulate
blood sodium. Is a dietary deficiency of sodium likely? Why or why not?
To maintain fluid and electrolyte balance. Kidneys retain or excrete sodium and water to regulate
blood pressure. A dietary deficiency of sodium is not likely because of sodium’s abundance in
food products.
8.
List calcium's roles in the body. How does the body keep blood calcium constant
regardless of intake?
Bone structure, cell membrane integrity, transport of ions, muscle action, nerve impulses,
regulates blood vessel wall muscle tone, helps regulate blood pressure, aids blood clotting, acts as
cofactor for enzymes. When levels fall, intestinal absorption increases, bone withdrawal
increases, and kidney excretion diminishes; these processes are regulated by a system of
hormones and vitamin D.
9.
Name significant food sources of calcium. What are the consequences of inadequate
intakes?
Calcium is found predominantly in milk and milk products. Inadequate intakes limit the bones’
ability to achieve optimal mass and density and increase risk of osteoporosis and associated
fractures.
10.
List the roles of phosphorus in the body. Discuss the relationships between calcium and
phosphorus. Is a dietary deficiency of phosphorus likely? Why or why not?
Bone structure, part of DNA and RNA, activates enzymes, part of ATP, part of lipid structure and
cell membranes. They combine as calcium phosphate in the crystals of bone and teeth, providing
strength and rigidity. A deficiency is unlikely because phosphorus is abundant in animal tissues,
eggs, and milk.
11.
State the major functions of chloride, potassium, magnesium, and sulfur in the body. Are
deficiencies of these nutrients likely to occur in your own diet? Why or why not?
Chloride: maintains pH balance, allows nerve transmission and muscle contraction, catalyst in
metabolism; magnesium: bone structure, protein synthesis, energy metabolism, muscle
relaxation; sulfur: protein structure. Deficiency is unlikely in these minerals because they
naturally occur in many foods.