Chapter 10: Micromineral (Zinc) Flashcards
commonly found as the _____ (Zn 2+)
divalent ion
amount of the mineral in an adult ranges from
1.5 to 3 g
occurs in all cells, tissues, organs, fluids, and secretions but is mainly concentrated (about 90% of the body’s zinc) in _____
muscle bones
over 95% is bound within various _____ of cells and cell membranes
metalloenzymes
most of the zinc in the blood is in the RBCs, which contain the zinc-containing enzyme _____ needed to convert carbon dioxide to bicarbonate ions (HCO3)
carbonic anhydrase
zinc - functions
component of more than 200 enzymes participating in a wide variety of catalytic, regulatory and structural function, including metabolic reactions such as synthesis and/or degradation of cho, lipids, chon, and nucleic acids
zinc - functions
interacts with _____ facilitating the uptake of glucose by cells of adipose tissues
insulin
zinc - functions
needed for the normal development and maintenance of the body’s _____
immune system
zinc - functions
important in stabilizing membrane structure and guarding it against _____
peroxidative damage
zinc - functions
important in _____ and important in mobilizing vitamin a from liver stores
night vision
zinc - functions
facilitates _____ and _____
wound healing and blood clotting
zinc - functions
regulates _____
gene expression
zinc - functions
influences _____
thyroid hormone function
zinc - functions
necessary for _____ and _____
visual pigments and taste reception
zinc - functions
involved in _____; and also in fetal development
sperm production
zinc - absorption and metabolism
absorbed in the _____, and is carried into the blood and goes to the pancreas where it is used in the formation of some digestive enzymes
small intestine
zinc - absorption and metabolism
the absorbed zinc binds to _____, a sulfur-rich protein that binds with metals such as zinc
metallothionein
zinc - absorption and metabolism
binds with another protein (_____ protein) to transport the mineral to the blood
cysteine-rich intestinal
zinc - absorption and metabolism
zinc that is carried within blood plasma is bound with different carrier proteins such as _____
albumin and transferrin
zinc - absorption and metabolism
_____ takes up some 30-40% of absorbed zinc, while the rest is distributed throughout the different organs and tissues
liver
zinc - absorption and metabolism
zinc loss from the body is via (3)
body surface, kidney, and gi tract
zinc - absorption and metabolism
most of the zinc is excreted in the
feces
zinc - interrelationship with other nutrients
zinc2 absorption is impaired by the following divalent cations: cd2+, cu2+, ca2+, fe2+
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zinc - interrelationship with other nutrients
the cations compete with one another for:
facilitating binding ligands in the intestinal cells
receptor sites in the erythrocytes
intracellular binding ligands within mucosal cells
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zinc - deficiency
individuals consuming unprocessed or minimally processed diets consisting of _____ or _____ and very minimal animal-source foods are at a greater risk for zinc deficiency
unrefined whole grains or unleavened whole bread
zinc - deficiency
symptoms:
-hair loss
-dermatitis and skin changes
-growth and retardation
-impaired taste acuity
-delayed wound healing
-decreased dark adaptation (night blindness)
-immunologic abnormalities
-delayed sexual maturity
zinc deficiency
zinc - toxicity
prolonged intake of zinc supplements results to:
-zinc-induced copper deficiency anemia
-depressed levels of wbc
-increased low-density lipoprotein and decreased high-intensity lipoprotein cholesterol
-decreased serum ferritin and hematocrit levels
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zinc - recommended intake
for adults (19 - >70 y/o) males
6.5 mg
zinc - recommended intake
for adults (19 - >70 y/o) females
4.6 mg
zinc - recommended intake
for pregnant
+5.1
zinc - recommended intake
for lactating
+7.0
zinc - food sources
animal foods readily absorbed than plant foods
meat, some shellfish, poultry, fish, grains, and vegetables
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