Ch. 8 Flashcards
the smallest physical units of a substance are
atoms
carbon and hydrogen are two examples of
atoms
in an atom, the nucleus has a positive charge and the electrons orbiting around the nucleus have a ___ charge
negative
a chemical reaction in which atoms lose electrons is
oxidation
what is not true about free radicals
our body has no mechanism to combat free radicals
what is an exchange reaction
a two-part metabolic reaction that involves a loss and gain of electrons
free radicals
are formed by exposure to air polllution and tobacco smoke
what is a required componet of an antioxidant enzyme system
antioxidant minerals
how do antioxidant minerals stabilize free radicals
break down and convert them to less damaging molecules
what disease has not been linked to free radical damange
type 1 diabetes
examples of antioxidant enxyme systems include superoxide dismutase, ___, and glutathione peroxidase
catalase
the most powerful and abundant form of vitamin e is
alpha-tocopherol
which water-soluble vitamin can regenerate vitamin e after it has been oxidized
vitamin c
about 90% of vitamin e is stored in
adipose tissue
what is not a function of vitamin e
improving the absorption of vitamin c if dietary intake is low
what food is rich in sources of vitamin e
mayonnaise, begetable oils, nuts, and seeds
taking vitamin e suplements along with ___ can cause uncontrollable bleeding
anticoagulants
a deficiency of ___ can result in the erythrocyte hemolysis, leading to anemia
vitamin e
what nutrient requires the most frequent consumption to assure adequate body stores
vitamin c
the deficiency disease associated with vitamin c is
scurvy
what is false about vitamin c
smokers sould consume less vitamin c than non smokers
what increases the rda fro vitamin c
smoking cigarettes
what cooking method would destroy the most vitamin c in food
boiling
what is a rich source of vitamin c
green and red peppers
consuming even moderately excessive doses of vitamin c supplements would be most harmful to individuals suffering from
hemochromatosis
symptoms of a vitamin c deficiency include
bleeding gums and loose teeth
beta-carotene is a precursor of
retinol
what is not true about carotenoids
beta-carotene is the only cartenoid that functions as an antioxidant
most of the bodys vitamin a is stores in the
liver
the most critical role that vitamin a plays in the human body is
maintaining healthy vision
the light sensitive pigment found in rod cells is formed by retinal and opsin is
rhodopsin
what food would be the best dietary source of preformed vitamin a
egg
both keshan disease and kashin-beck disease are associated with a ___ deficiency
selenium
what is false about the mineral selenium
selenium is present only in foods of animal origin
what hormone requires selenium for its synthesis
thyroxine
where does the body store selenium
in amino acids in the body
diseases that cause the malbsorption of fat can result in a deficiency of ___
vitamin a
what mineral can function as an antioxidant
selenium
