Final - Zinc

Question 1

What enhances the absorption of zinc?

Answer 1

citric and picolinic acid
histidine, cysteine, lysine and glycine
Glutathione (cysteine + glutamate + glycine)
tripeptides

Question 2

What inhibits the absorption of zinc?

Answer 2

phytate - wheat,oxalate
polyphenols
fibers
folic acid
iron, calcium, copper

Question 3

What are the 3 roles of zinc

Answer 3

• structural - transcription
• regulatory - zinc regulates thionein and ZnT1, metal regulatory elements
• catalytic -

Question 4

What are the zinc (cofactor) dependent enzymes?

Answer 4

carbonic anhydrase - respiration
alkaline phosphatase
alcohol dehydrogenase
carboxypeptidase - protein digestion
amiolelvulinic acid dehydratase
superoxide dismutase
phospolipase C
matrix metaproteases
DNA polymerase

Question 5

What are the biological processes dependent upon zinc?

Answer 5

Immune function (B and T cell)
Respiration
Antioxidant defense - superoxide dismutase
protein digestion
basal metabolic rate
DNA synthesis

Question 6

What are they symptoms of Zinc deficiency?

Answer 6

Immune deficiencies
diarrhea and intestinal inflammation
impaired taste
delayed wound healing

behavior disturbances
alopecia
glossitis

growth retardation 
delayed sexual retardation
delayed sexual maturation 
impotence
hypogonadism
hypospermia

Question 7

What are the five general causes of zinc deficiency?

Answer 7

Inadequate intake
increased requirements
Malabsorption
Increased losses - alcoholism
Impaired utilization - diabetes & chronic long term infectons

Question 8

What are the symptoms of zinc toxcity?

Answer 8

1- 2 g Zinc = acute toxicity

metallic taste
nausea and vomiting
epigastric pain
abdominal cramps
dizziness
chills

Question 9

Effects of zinc on other minerals

Answer 9

-Chronic ingestion (25 mg/day) of zinc results in copper deficiency (impairs copper absorption)
& iron deficiency (ceruloplasmin & hephaestin - not functional because copper is required as cofactor) –> iron deficiency anemia

Caused by excessive intake