Zinc Flashcards
zinc is widely distributed in the body and is found in:
all tissues and fluids
sources of zinc
shellfish, beef, red meat, nuts, legumes
zinc is more bioavailable in meat sources or plant sources
meat source
why is zinc less bioavailable in plant sources
because they are high in phytic acid which inhibits zn aborption
zn first needs to be _____ from aa’s and nucleic acids in the ST and SI
hydrolyzed
before it can be absorpbed, zn in hydrolyzed in the ST and SI by :
hydrochloric acid
proteases
nucleases
the absorption of zn primarily occurs in the
SI
the absorption of zn occurs in what three pathways
carrier mediated process (low intakes) passive diffusion (high intake) paracellular absorption (high intake)
factors that enhance zn aborption
citric acid
picolinate
prostaglandins
low zinc status
factors that inhibit zinc absorption
phytates
oxalates
polyphenols
Fe, Ca, Mg
once absorbed the intestinal cell can do three things with zinc:
used
stored as metallotionein
transported by Znts to blood
CRIP transports Zn within the ____ of cells
cytoplasm
zn in blood is bound to
albumin
zn in found in all organs of the body especially
liver kidney muscle skin bone
storage of zinc is usually bound to
thionein as metallothionein (binds copper)
functions of zinc
growth and dev
immune
neurological function
reproduction
the function of zinc can be further divided into three roles
catalytic role
structural role
regulatory role
the catalytic role of zinc involves over 300 different enzymes such as
alcohol/retinol dehydrogenase
carboxypeptidase A and aminopeptidase
polyglutamate hydrolase
alkaline p hosphatase
the structural role of zine is important in the structure of
proteins and cell membranes
Zinc_____ proteins have been found to regulate gene expression by acting as transcription factors
finger
zn also plays a role in cell signaling and ha been found to influence :
hormone release
insulin release
nerve impulse transmission
T or F zin has a role in apoptosis
true
Zn is requried for _____ differentiation and function
t-cell
zn is primarily excreted through the____
GIT
S&S of zn deficency
growth retardation delayed sexual maturation in children dermatitis diarrhea impaired immunity impaired wound healing dysgeusia night blindness hairloss white spots on fingernails
______ abuse has been associated with severe zn deficiencies
chronic alcohol abuse
those are higher risk of zn deficiency are
premature and low birth weight infants
older breast fed infants with inadequate zn intake
teens
pregnant/lactating women
elderly
those with IBD or severe prolonged diarrhea
strict vegetarians
clinical indications for zn supplementation
common cold
the major consequence of long term consumption of excessive zn is ___ deficiency
copper
acute zn toxicity sx include
metallic taste
h/a
n/v/ bloody diarrhea
abd cramps
zinc is required for the conversion of _____ to retinal
retinol
Ca, Mg and Fe (increase/decrease) Zn absorption
decrease
NAC may (increase/decrease) zn excretion
increase
___ and ____ can displace zinc and disrupt normal zn function
cadmium and lead
assessment of status
zinc tally test
serm zinc
RBC
hair zinc, saliva,
