Ch 10 Flashcards
The gaining of electrons by an atom during metabolism is called:
A) oxidation.
B) reduction.
C) radiation.
D) mineralization.
B) reduction.
Which of the following statements is TRUE regarding free radicals?
A) Free radicals are formed as a by-product of healthy metabolism.
B) Our body has no mechanism to combat free radicals.
C) Exposure to pollution decreases free radical production.
D) A free radical is an atom with paired electrons in its outermost shell.
A) Free radicals are formed as a by-product of healthy metabolism.
Which of the following statements about antioxidants is TRUE?
A) Antioxidants are formed in the body.
B) Antioxidants oxidize free radicals.
C) Antioxidants reduce free radicals by removing an electron.
D) Antioxidants donate an electron, thus reducing the free radical.
D) Antioxidants donate an electron, thus reducing the free radical.
Which antioxidant enzyme system functions by removing hydrogen peroxide from the body by converting it into water and oxygen?
A) superoxide dismutase
B) catalase
C) glutathione peroxidase
D) microsomal enzyme-oxidizing system
B) catalase
Which of the following are required components of many antioxidant enzyme systems?
A) antioxidant minerals
B) antioxidant vitamins
C) phytochemicals
D) gastrointestinal microflora
A) antioxidant minerals
From what source does our body obtain the majority of its antioxidants?
A) from sunlight
B) from the by-products of healthy metabolism
C) from the diet
D) gastrointestinal microflora
C) from the diet
How do antioxidant vitamins stabilize free radicals?
A) donate electrons or hydrogens
B) enzymatic destruction
C) phagocytosis
D) break down and convert them to less damaging molecules
A) donate electrons or hydrogens
Which of the following diseases has been linked to free radical damage?
A) cancer
B) celiac disease
C) anemia
D) gallstones
A) cancer
The most powerful and abundant form of vitamin E is:
A) alpha-tocopherol.
B) alpha-tocotrienol.
C) gamma-tocopherol.
D) delta-tocopherol.
A) alpha-tocopherol.
Which water-soluble vitamin can regenerate vitamin E after it has been oxidized?
A) vitamin D
B) vitamin B12
C) vitamin C
D) folate
C) vitamin C
About 90% of vitamin E is stored in:
A) adipose tissue.
B) the liver.
C) cell membranes.
D) the skin.
A) adipose tissue.
Which of the following is a function of vitamin E?
A) protecting PUFA (polyunsaturated fatty acids) in cell membranes from oxidation
B) regenerating vitamin C by donating an electron
C) improving the absorption of vitamin C if dietary intake is low
D) increasing bone density
A) protecting PUFA (polyunsaturated fatty acids) in cell membranes from oxidation
Which of the following foods are the richest sources of vitamin E?
A) milk and dairy products
B) fruits and vegetables
C) meat, fish, and poultry
D) vegetable oils
D) vegetable oils
Which of the following foods will have the least amount of viable vitamin E?
A) chicken fried in vegetable oil
B) bread dipped in sunflower oil
C) peanuts, dry roasted
D) salad with canola oil and vinegar
A) chicken fried in vegetable oil
Taking vitamin E supplements along with ___ can cause uncontrollable bleeding.
A) antidepressants
B) anticoagulants
C) cholesterol-lowering medications
D) oral contraceptives
B) anticoagulants
Vitamin E is added to many oil-based skin care products because:
A) it prevents oxidation in these products.
B) it has an additive affect on the function of the products.
C) it is an inactive filler.
D) it improves the smell and texture of the products.
A) it prevents oxidation in these products.
Vitamin E is critical for:
A) normal fetal and early childhood development.
B) athletic performance.
C) postmenopausal women.
D) adolescent growth.
A) normal fetal and early childhood development.
Diseases that cause the malabsorption of fat can result in a deficiency of:
A) copper.
B) vitamin E.
C) vitamin C.
D) selenium.
B) vitamin E.
Which of the following nutrients requires the most frequent consumption to ensure adequate body stores?
A) vitamin A
B) vitamin E
C) vitamin C
D) beta-carotene
C) vitamin C
The deficiency disease associated with vitamin C is:
A) scurvy.
B) erythrocyte hemolysis.
C) night blindness.
D) Keshan disease.
A) scurvy.
Vitamin C assists in the formation of the structural protein called ___.
A) elastin
B) collagen
C) titan
D) ostiod
B) collagen
The doctor has recently told Julie that she is anemic. Julie should consume ___ with her iron supplement to increase its absorption.
A) a tablespoon of castor oil
B) a glass of milk
C) a glass of orange juice
D) scrambled eggs
C) a glass of orange juice
Which of the following increases the RDA for vitamin C?
A) smoking cigarettes
B) drinking alcohol
C) following a vegan diet
D) taking vitamin C supplements
A) smoking cigarettes
Which of the following are rich sources of vitamin C?
A) milk and cheese
B) seafood
C) wheat and oats
D) green and red peppers
D) green and red peppers
Which of the following is the best source of vitamin C?
A) citrus fruit
B) pork chops
C) hazel nuts
D) butter
A) citrus fruit
Absorption of which mineral is enhanced by vitamin C?
A) iron
B) copper
C) selenium
D) calcium
A) iron
Which of the following symptoms is associated with consuming a megadose of vitamin C?
A) night blindness
B) scurvy
C) nausea and diarrhea
D) erythrocyte hemolysis
C) nausea and diarrhea
Which of the following is considered an essential nutrient?
A) glycerol
B) beta-carotene
C) homocysteine
D) vitamin E
D) vitamin E
Which of the following carotenoids can be converted to retinol in the body?
A) lutein
B) beta-carotene
C) lycopene
D) retinol
B) beta-carotene
Which of the following is a function of carotenoids?
A) produces thyroxine
B) activate the glutathione peroxidase enzyme system
C) supports the immune system
D) increases cellular metabolic rate
C) supports the immune system
Provitamins are:
A) vitamins with overwhelmingly positive effects when taken in the correct amounts.
B) inactive forms of vitamins that the body cannot use until they’re converted to their active form.
C) prooxidents that have taken a new form.
D) vitamins with antioxidant properties.
B) inactive forms of vitamins that the body cannot use until they’re converted to their active form.
Compared to vitamin E, beta-carotene is:
A) a relatively weak antioxidant.
B) more easily absorbed and utilized by the body.
C) a better choice for people with GI tract problems.
D) a stronger antioxidant.
A) a relatively weak antioxidant.
Which of the following contains the greatest amount of bioavailable beta-carotene?
A) 1 cup raw carrots
B) 1 cup frozen carrots
C) 1 cup lightly cooked carrots
D) 1 cup thoroughly cooked carrots
C) 1 cup lightly cooked carrots
Foods that use beta-carotene as a natural coloring agent:
A) generally must be processed heavily.
B) are not significant sources of beta-carotene.
C) are largely foods with a high fat content.
D) also acquire a distinctive taste.
B) are not significant sources of beta-carotene.
The retinoid that has the most significant physiological role in the human body is:
A) retinol.
B) retinoic acid.
C) retinal.
D) beta-carotene.
A) retinol.
Where is beta-carotene converted to retinol?
A) in the stomach
B) in the liver
C) in the small intestine
D) in the large intestine
C) in the small intestine
Which of the following foods would be the BEST dietary source of pre-formed vitamin A?
A) carrots
B) egg
C) cantaloupe
D) rice
B) egg
Vitamin A affects our vision in two ways. it enables us to react to changes in brightness, and:
A) it enables us to see different colors.
B) it enables us to focus on distant objects.
C) it supports eye functioning later in life.
D) it supports the development of eye functioning in fetuses.
A) it enables us to see different colors.
When levels of vitamin A are deficient, people suffer from a condition known as:
A) astigmatism.
B) near-sightedness
C) night blindness.
D) partial blindness.
C) night blindness.
Which of the following hormones requires selenium for its synthesis?
A) estrogen
B) insulin
C) cortisol
D) thyroxine
D) thyroxine
Where in the body is selenium contained?
A) in the liver
B) in adipose tissue
C) in the lymph system
D) in amino acids
D) in amino acids
Which of the following foods is MOST likely to have the highest concentration of selenium?
A) apples
B) whole wheat pasta
C) cheese
D) liver
D) liver
The most common form of cancer in the United States is cancer of the:
A) lung.
B) skin.
C) colon.
D) stomach.
B) skin.
The specific term for substances that can cause cancer is:
A) free radicals.
B) tumors.
C) carcinogens.
D) mutations.
C) carcinogens.
Research studies have demonstrated an association between a reduced risk for cancer and:
A) the use of vitamin C supplements.
B) increased consumption of fruits and vegetables.
C) increased consumption of monounsaturated fatty acids.
D) the use of beta-carotene supplements.
B) increased consumption of fruits and vegetables.
Which of the following has been associated with an increased risk for cancer?
A) high fat diet
B) caffeine
C) fluoridated water
D) omega-3 fatty acids
A) high fat diet
The leading cause of death for adults in the United States is:
A) cancer.
B) cardiovascular disease (CVD).
C) diabetes.
D) AIDS.
B) cardiovascular disease (CVD).
Low-grade inflammation is associated with which biochemical marker?
A) HDL cholesterol
B) LDL cholesterol
C) insulin
D) C-reactive protein
D) C-reactive protein
Regarding second-hand smoke from tobacco products, research indicates that:
A) minimal exposure poses few risks.
B) exposure is situational. not all products exert the same level of danger.
C) air circulation significantly mitigates the problem of exposure.
D) there is no risk-free level of exposure.
D) there is no risk-free level of exposure.
Growing evidence of the past two decades indicates that ___ does not reduce cancer risk.
A) antioxidant supplementation
B) reducing exposure to UV rays
C) antioxidants consumed in foods
D) increasing physical activity
A) antioxidant supplementation
About 90% of the vitamin A we absorb is stored in the:
A) pancreas.
B) liver.
C) intestines.
D) kidneys.
B) liver.
When an oxygen molecule becomes a free radical, it is referred to as a(n):
A) reactive oxygen species (ROS).
B) carcinogen.
C) prooxidant.
D) antioxidant.
A) reactive oxygen species (ROS).
A(n) ___ is a highly unstable atom with an unpaired electron.
A) provitamin
B) antioxidant
C) prooxidant
D) free radical
D) free radical
Antioxidants ___ an electron or hydrogen atom to stabilize a free radical.
A) take on
B) eliminate
C) donate
D) transform
C) donate
The reason most fast foods don’t contain much vitamin E is because:
A) they have too much fat content.
B) heating vegetable oils destroys vitamin E.
C) vitamin E cannot be present in cooking oils.
D) vitamin E-containing foods are best cooked slowly.
B) heating vegetable oils destroys vitamin E.
Vitamin A is derived from what provitamin?
A) beta carotene
B) panthenol
C) provitamin D3
D) ergosterol
A) beta carotene
Your skin can trun yellow or orange if you frequently consume foods that are high in:
A) vitamin E.
B) selenium.
C) vitamin A.
D) beta-carotene.
D) beta-carotene.
Vitamin A is transported through the bloodstream to target tissues and cells with the assistance of ___.
A) retinol-binding protein
B) prooxidants
C) anticoagulants
D) tocopherols
A) retinol-binding protein
True ___ deficiencies are uncommon in humans.
A) beta-carotene
B) vitamin A
C) vitamin C
D) vitamin E
D) vitamin E
Advanced vitamin A deficiency can lead to__, a condition of irreversible blindness.
A) hyperkeratosis
B) Kashin-Beck disease
C) xeropthalmia
D) anemia
C) xeropthalmia
In laboratory blood tests, the marker that indicates the degree of inflammation is called:
A) iodopsin.
B) C-reactive protein.
C) reactive oxygen species (ROS).
D) selenomethionine.
B) C-reactive protein.
Copper, zinc, and manganese are part of the __ antioxidant enzyme system.
A) superoxide dismutase
B) catalase
C) haloperoxidase
D) glutathione peroxidase
A) superoxide dismutase
Vitamin E improves vitamin A’s absorption by the body.
True
Dairy products are good sources of vitamin E.
False
Deep-frying decreases the availability of vitamin E in vegetable oil.
True
Ascorbic acid is stored in our bodies.
False
Research suggests that vitamin C supplements taken daily can reduce the incidence of the common cold.
False
It is difficult to consume adequate vitamin C from the diet alone.
False
Today, scurvy is rare in developed countries.
True
Smoking increases the need for vitamin C.
True
Carotenoids are better absorbed from cooked foods.
True
Beta-carotene is a hydrophobic compound.
True
Beta-carotene has no known essential role in the body. Therefore, an RDA has not been established.
True
Foods in which beta-carotene is used as a coloring agent have a significant amount of dietary beta-carotene.
False
Vitamin A is present only in animal food sources.
False
Selenium toxicity occurs from an overconsumption of foods rich in this mineral.
False
Selenocysteine is the active form of selenium.
True
Once the DNA of a cell is mutated, the development of cancer is inevitable.
False
People who regularly consume fruits and vegetables have a reduced risk for CVD.
True
Glutathione peroxidase is a free radical formed from oxidative metabolism.
False
Taking megadoses of vitamin C is fatal.
False
Naturally occurring compounds found in plants and believed to have health-promoting properties are called:
A) steroids.
B) antioxidants.
C) phytochemicals.
D) chlorofluorocarbons.
C) phytochemicals.
The prefix “phyto” means:
A) light.
B) plant.
C) fiber.
D) photon.
B) plant.
Which type of studies are most commonly used as evidence for the benefits of phytochemicals?
A) epidemiological
B) experimental
C) survey
D) retrospective
A) epidemiological
Antioxidants have the capacity to neutralize:
A) DNA.
B) lipids.
C) free radicals.
D) water.
C) free radicals.
Which of the following is the BEST expression of the synergistic action of phytochemicals?
A) Each phytochemical has an independent function.
B) Phytochemicals oppose the action of certain vitamins.
C) Phytochemicals interact with each other and with other substances to provide a greater summative effect.
D) Phytochemicals can neutralize free radicals.
C) Phytochemicals interact with each other and with other substances to provide a greater summative effect.
In addition to their antioxidant properties, phytochemicals are also believed to:
A) reduce inflammation that can lead to potentially serious disease.
B) aid in childbirth.
C) assist with sleep.
D) retard hair thinning as a result of age or chemical exposure.
A) reduce inflammation that can lead to potentially serious disease.
Conditions that typically occur later in life as the result of lifelong accumulated risk are called:
A) low-risk diseases.
B) cancer.
C) secondary diseases.
D) diseases of aging.
D) diseases of aging.
A key reason why an RDA for phytochemicals has been difficult to establish is due to:
A) their synergystic effect.
B) their naturally-occuring genesis.
C) their variety of forms.
D) their broad functions.
A) their synergystic effect.
Resveratrol, which is present in wine and grapes and thought to have protective effects against cancer, is a member of the phytochemical group called:
A) flavinoids.
B) phenolics.
C) phytoestrogens.
D) carotinoids.
B) phenolics.
Phytochemicals may be ineffective or even harmful when:
A) heated
B) diluted.
C) consumed as supplements.
D) consumed in raw foods.
C) consumed as supplements.
Phytochemicals are synthetic substances.
False
Phytochemicals are regarded as nutrients.
False
Phytochemicals have established daily recommended intakes.
False
Over 10,000 different phytochemicals have been identified.
True
Some free radicals are unavoidable by-products of normal metabolism.
True
Oxidative damage has been linked to the aging process.
True
Phytochemicals have greater benefits if consumed at higher doses, in supplement form.
False
Carotinoids are probably the most studied class of phytochemicals.
True
Free radicals are only produced in response to radiation, pollution, industrial chemicals, tobacco smoke, or infections.
False
Scientists now believe that phytochemicals may benefit health by stressing our cells.
True
A basic principle of toxicology states that doseage is not an important factor.
False
Experts recommend beta-carotene supplementation to help with chronic disease prevention or treatment.
False
