Download Chapter 5: Nutrients at Work

Chapter 5: Nutrients at Work
1. Absorption--nutrients move into
the blood stream; usually takes
place in the small intestine.
2. Adequate intakes--Dietary Reference
Intake used when dietary allowance for a
nutrient can’t be scientifically established.
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Anemia--Blood disorder characterized
by lack of energy, weakness, shortness
of breath, and cold hands and feet;
caused by lack of iron.
basal metabolism--Minimum amount of
energy needed to maintain basic body
processes
Calorie--Amount of energy needed to raise
temperature of 1 kilogram of water 1 degree
Celsius;a way to measure energy.
 Chyme--Thick liquid resulting as
stomach breaks down food
mechanically through peristalsis
 Dietary Reference Intakes(DRI)-Standards for assessing nutrient needs
among people of different age and
gender groups
Digestion--Mechanical and chemical process
that breaks food down to release nutrients in
forms the body can absorb for use.
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Enzyme--Special proteins that help
chemical reactions take place
Esophagus--Tube that connects mouth
and stomach
Glucose--Blood sugar formed when
carbohydrates are fully broken down
chemically.
Glycogen--Storage form of glucose
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Malnutrition--Deficiency or severe
shortage of nutrient, caused by faulty or
inadequate nutrition.
Metabolism- Process through which
living cells use nutrients in chemical
reactions in order to provide energy for
vital processes and activities oxidation--Chemical reactions that
combine elements with oxygen.
Pancreas--Gland connected to small intestine;
produces pancreatic juice that breaks down
carbohydrates, proteins, and fats.
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Peristalsis--Muscle action of esophagus
(contracting and relaxing) that forces
food into stomach.
Recommended Dietary Allowances
(RDA)--Amount of a nutrient needed by
98 percent of the people in given age
and gender group
Villi--Billions of tiny fingerlike projections
that line folds of small intestine.
Answer the following questions:
What basic functions do the six nutrients
provide?
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Carbohydrates: energy
Fats: energy and insulation
Proteins: build, repair, and maintain
body tissues
Vitamins: regulate vital processes
Minerals: help the body work properly
Water: assists chemical reactions and
transports materials to and from cells.
2. Are there different types of
malnutrition? Explain.
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Yes; malnutrition can result from a
severe shortage of a nutrient or from an
excess of certain nutrients.
3. How can people benefit from healthy
habits and good nutrition?
Healthy appearance, fitness, healthy weight,
lower likelihood of illness, easier healing,
easier to cope with emotions, possible
avoidance of future health problems.
4. If you limit your food choices, how
is nutrient teamwork affected?
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Negatively; nutrients rely on one
another for many processes.
5. Name and describe the two
components of the Dietary Reference
Intakes (DRIS.
RDAs are the amount of a nutrient needed by
98 percent of the people in a given age and
gender group; Als are used when RDA for a
nutrient can’t be scientifically established.
6. What is the relationship between
DRSs and nutrition labels?
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DRIs are used as the basis for Daily
Values (DVs), which appear on nutrition
labels.
7. What is the purpose of digestion?
To break food down and release
nutrients that your body can absorb.
8. What role do enzymes play in
digestion?
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They help chemical reactions take place
as food breaks down.
9. Does gravity force foods through the
digestive system? Explain.
No; peristalsis is the main force that
pushes food through the digestive
system.
10. Compare the rates that
carbohydrates, proteins, and fats take to
break down before leaving the stomach.
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Carbohydrates: usually 1--2 hours
Proteins: about 3--5 hours
Fats: up to 12 hours.
11. Critical Thinking: Predict what might
happen if food passes through the digestive
system more quickly than normal.
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Food might not break down completely,
limiting the nutrients that could be
absorbed.
12. During digestion, what happens in
the small intestine?
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Digestive juices act on chyme to further
break down carbohydrates, proteins,
and fats.
13. How do villi aid absorption?
They increase the surface area of the
small intestine and allow more nutrients
to be absorbed.
14. What is glucose and how is it used?
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The simple sugar formed from
carbohydrates; used as the body’s basic
fuel.
15. What happens to glucose if it isn’t
needed right away?
A limited amount is stored as glycogen;
the rest becomes body fat.
16. What is metabolism?
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The process by which cells use
nutrients for vital processes and
activities.
17. What do calories measure?
The amount of energy available in food
or the amount of energy used by the
body for activities.
18. If two people have different basal
metabolic rates, what does that mean?
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Their bodies use different amount of
energy to carry out automatic functions.
19. How do calories relate to activity
level?
The more active you are , the more
calories you burn.