Questions and Answers
Which of the microminerals is considered essential for normal brain function?
manganese
Iron content of the average Western diet is estimated to be about?
5 to 7 mg iron per 1,000 kcal
Which of the following dietary substances inhibits uptake of non-heme iron?
tea
Absorption of dietary iron is regulated by _____, produced by the liver when iron stores are high.
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Which mineral is critical for oxidizing iron to be bound by transferrin for delivery to the tissues?
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Where would you find iron regulatory element binding protein (IRE-BP)?
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In the presence of low intracellular iron, what happens to ferritin mRNA?
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The binding of iron by proteins defends the cells against?
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Hemosiderin is the primary storage form of iron in cells.
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The following vitamins/minerals are required for heme synthesis.
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Which mineral facilitates transfer of electrons in the electron transport chain?
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Excessive intake of non-heme iron interferes with absorption of which mineral?
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Hemoglobin and hematocrit are common measurements for assessment of nutriture for which mineral?
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ZIP4 is what?
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Which trace mineral participates in the greatest number of enzyme systems?
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The enzyme that converts retinol to retinal and ethanol to acetyl-aldehyde contains 4 ____ atoms.
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Zinc is important for taste perception as a component of _____.
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At the cellular level, which mineral interacts with vitamin A by promoting growth?
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Which vitamin may enhance copper reduction?
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Which of the following dietary components impedes copper absorption?
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The protein that plays a dual function in both iron and copper homeostasis is:
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What glycoprotein serves as a transporter of copper, an antioxidant, and an oxidative enzyme?
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What two minerals can cause damage to cells when in their free ion forms?
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What genetic disorder causes copper toxicity?
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Free selenide can be converted into selenophosphate.
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Which mineral is an essential factor in the action of glutathione peroxidase in the reduction of organic peroxides?
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When superoxide radicals accumulate, what happens to hydrogen peroxide?
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Glutathione loses two electrons when it acts as an antioxidant. Glutathione is _____.
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What is important in antioxidant DEFENSE?
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Which micromineral is necessary for iodine metabolism?
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Which non-metal nutrient deficiency is associated with Keshan disease?
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Chromium absorption is inhibited by _____ and enhanced by _____.
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Which mineral is thought to potentiate the action of insulin?
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The primary physiological role of which mineral is as a constituent in the thyroid hormones?
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Study Notes
Microminerals and Their Functions
- Manganese is essential for normal brain function.
- Average iron intake in the Western diet ranges from 5 to 7 mg per 1,000 kcal.
- Tea inhibits the absorption of non-heme iron.
- Hepcidin regulates dietary iron absorption; produced by the liver in response to high iron stores.
- Copper is necessary for oxidizing iron to allow binding by transferrin for tissue delivery.
Iron Regulation and Storage
- Iron regulatory element binding protein (IRE-BP) is located in the cytosol.
- Low intracellular iron causes IRE-BP to bind to iron response elements, decreasing ferritin abundance.
- Iron-binding proteins protect cells from oxidative damage caused by free radicals.
- Hemosiderin is not the primary storage form of iron; ferritin is the main storage protein.
- Important nutrients for heme synthesis include vitamin B6, zinc, and iron.
Zinc and Its Roles
- Iron facilitates electron transfer in the electron transport chain.
- Excessive non-heme iron intake can hinder zinc absorption.
- Hemoglobin and hematocrit levels are crucial for monitoring iron status.
- ZIP4 is the main transporter for zinc into enterocytes.
- Zinc plays a significant role in numerous enzyme systems and is key for taste perception through its component, gustin.
Zinc's Interaction and Functions
- Zinc aids in the growth of cells and synthesis of retinol-binding protein, influencing vitamin A.
- Ascorbic acid may enhance copper reduction.
- Phytic acid impedes copper absorption.
- Ceruloplasmin is critical for both iron and copper homeostasis, functioning as a transporter and antioxidant.
Selenium and Antioxidant Defense
- Iron and copper in free ion forms can be harmful to cells.
- Menkes disease is a genetic disorder that leads to copper toxicity.
- Free selenide in selenium metabolism can convert into selenophosphate.
- Selenium is a vital component of glutathione peroxidase, reducing organic peroxides and hydrogen peroxide.
- Superoxide dismutase facilitates the conversion of superoxide radicals into hydrogen peroxide, which is then turned into water and oxygen by catalase or glutathione peroxidase.
Additional Microminerals
- Glutathione is oxidized as it acts as an antioxidant, losing two electrons.
- Both selenium and chromium play roles in antioxidant defense and metabolism.
- Selenium is necessary for proper iodine metabolism and is linked to Keshan disease, which presents as cardiomyopathy.
- Chromium's absorption can be inhibited by antacids and enhanced by picolinate; it is believed to enhance insulin action.
- Iodine is a crucial component of thyroid hormones, underlining its physiological importance.
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Description
Test your knowledge with these flashcards from Nutrition Chapter 13. Explore essential microminerals, iron content in diets, and factors affecting iron absorption. Perfect for students aiming to master the concepts in nutrition science.