Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NUTR2101 > Minor Minerals > Flashcards

Minor Minerals Flashcards

1
Q

Zinc absorption is influenced by a variety of factors. Which of the following increase zinc bioavailability for absorption?
pick 2

  1. Non-heme iron
  2. Low to moderate zinc concentration in food or supplements
  3. Presence of yeast in grain sources of foods
  4. Large concentration of zinc in food or supplement
  5. Zinc consummed from whole grains
  6. Zinc sufficiency status
A
  1. Low to moderate zinc concentration in food or supplements

3. Presence of yeast in grain sources of foods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

A deficiency of selenium results in a deficiency of [A] overtime

A

A deficiency of selenium results in a deficiency of Correct Iodine function overtime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which of the following is a symptom of zinc deficiency? from the following

  1. Increased taste sensitivity
  2. Poor wound healing
  3. Increased sperm count and motility
  4. Megaloblastic anemia
  5. Goiters
A

Poor wound healing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of the following population groups is at highest risk of iron-deficiency anemia?
1. Menopausal women

  1. Newborn babies
  2. Builders and carpenters
  3. Vegetarian dieters
  4. Weight-training athletes
A
  1. Vegetarian dieters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The proteins ____________ oxidize ferrous iron to ferric iron.
1. Heme and non-hemeoxygenase

  1. Hephaestin and ceruloplasmin
  2. Ferritin and albumin
  3. Ferroportin and hepsidin
  4. Hemosiderin and ferritin
A

Correct Hephaestin and ceruloplasmin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which type of dietary iron is most efficiently absorbed?
1. Ferrous

  1. In Fe3+ form
  2. Elemental iron
  3. Non-heme iron
  4. Ferric
A
  1. Ferrous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Zinc induces the synthesis of metallothionein, which:

Answers:
1. Is a zinc-containing enzyme in the antioxidant defence network

  1. Slows down the entry of zinc into the blood stream
  2. Increases the bioavailability of zinc to cells
  3. Is the primary protein carrier of zinc in the blood
  4. Is the storage form of zinc in the liver
A

Correct2.

Slows down the entry of zinc into the blood stream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Zinc induces the synthesis of metallothionein, which:

Answers:
1. Is a zinc-containing enzyme in the antioxidant defence network

  1. Slows down the entry of zinc into the blood stream
  2. Increases the bioavailability of zinc to cells
  3. Is the primary protein carrier of zinc in the blood
  4. Is the storage form of zinc in the liver
A

2.

Slows down the entry of zinc into the blood stream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Goitrogenic foods that can inhibit iodine metabolism include:

  1. Raw cabbage, broccoli and cauliflower
  2. None of these are goitrogenic foods
  3. Cooked sprouts, lettuce and capsicums
  4. Cooked cabbage, broccoli and cauliflower
  5. Raw sprouts, lettuce and capsicums
A

1.

Raw cabbage, broccoli and cauliflower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Transferrin

A

Transports iron to tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hephaestin

A

Converts Fe2+ to Fe3+ in the basolateral membrane of enterocytes, for transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ferrireductase

A

Converts Fe3+ to Fe2+ in brush border of enterocytes for absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Hemosiderin

A

Stores iron in organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cerruloplasmin

A

Converts Fe 2+ to Fe3+ in the blood circulation, for transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The transport of iron out of the intestinal cell for incorporation into serum transferrin is facilitated by ___________and the conversion to ____________by _____________.
1.
Hephaestin; ferric iron; ferroportin

  1. Hepcidin; ferric iron; ferroxidase.
  2. Ferroportin; ferric iron; hephaestin
  3. Hepcidin; ferric iron; ferroportin.
  4. Hepcidin; ferous iron; ferroportin
A

Ferroportin; ferric iron; hephaestin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The signs/symptoms of copper deficiency include:

A

Osteopenia, anemia, low white blood cells count

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The biologically active form of selenium is

A

Selenocysteine:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Iron is stored in the liver and organs as:

A

Ferritin and hemosiderin

19
Q

Neurological cretinism seems to have re-appeared in Australia due to reduced positive contamination opportunities.
T OR F

A

T

20
Q

Which of the following is associated with copper toxicity?

Answers:
1.
Hemochromatosis

  1. Keshan’s disease
  2. Grave’s disease
  3. Wilson’s disease
  4. Lou Gehrig’s disease
A

4.

Wilson’s disease

21
Q

When body cells need more iron:

Answers:
1.
Hepcidin production is upregulated

  1. The number of transferrin receptors on cell membranes increases
  2. The number of trasferrin receptors on cell membranes remains unchanged
  3. The number of transferrin receptors on cell membranes decreases
  4. More enteral cells are sloughed off
A

The number of transferrin receptors on cell membranes increases

22
Q

The “mucosal block” theory explains how the body protects itself from excess absorption of dietary minerals, such as:

Answers:
1.
Fluoride

  1. Calcium
  2. Manganese
  3. Iodine
  4. Zinc
A

Zinc

23
Q

Zinc is involved in all of these functions except:

Answers:
1.
Alcohol metabolism

  1. Enzymatic antioxidant system
  2. Blood glucose homeostasis
  3. Digestion
  4. Vitamin receptors stabilisation
A

3.

Blood glucose homeostasis

24
Q

The mechanism by which fluoride is involved in dental health is understood to be

A

Increasing the teeth protective layer from bacteria

25
Q

In iron-deficiency anemia, the red blood cells are usually classified as:

Answers:	
1. 
Similar to B12 deficiency anemia
2. 
 Microcytic and hypochromic
3. 
Microcytic  and hyperchromic
  1. Normocytic and hypochromic
  2. Megaloblastic and hypochromic
A

Microcytic and hypochromic

26
Q

Which of the following best describes the sequence of events leading to the development of goiter in iodine deficiency?

  1. Low circulating iodine; decreased secretion of TSH; hyperplasia and hypertrophy of thyroid tissue
  2. Low circulating TSH; increased secretion of T4; hyperplasia and hypertrophy of thyroid tissue
  3. Low circulating T4; increased secretion of TSH; hyperplasia and hypertrophy of thyroid tissue
  4. Low circulating TSH; increased secretion of T3; hyperplasia and hypertrophy of thyroid tissue
  5. Low circulating T3; increased secretion of TSH; hyperplasia and hypertrophy of thyroid tissue
A

Correct3.

Low circulating T4; increased secretion of TSH; hyperplasia and hypertrophy of thyroid tissue

27
Q

Manganese activity includes all the following except: [A]

Selected Answer:
Manganese activity includes all the following except:

All Answer Choices
Cofactor in gluconeogenesis
Cofactor in redox homeostasis
Cofactor in alcohol metabolism
Cofactor in wound healing
Cofactor in bone proteins formation
Cofactor in cholesterol synthesis
A

Correct Cofactor in alcohol metabolism

28
Q

Which of the following enzymes are copper dependant?

A

Superoxide dismutase, cerruloplasmin

29
Q

What are the minor minerals? what are their major functions?

A

Iron - hemoglobin, respiration, immune, cognitive development, energy metabolism -fatigue anemia

Zinc - immune function, growth and development, stabilize cell membranes and body proteins - dermatitis diarrhea, decreased apatite and taste, infection poor growth and development

Copper - aids iron mtabolism, antioxidant enzymes, involved conective tissue metabolism - anemia , low white blood cell count , poor growth

Manganese - cofactor several enzymes, involved carb metabolism and antioxidant protector - poor growth, skeletal abnormalities

Iodine - thyroid hormone component, basal metabolims growth and development- goiter, cretinism

Selenium- part antioxidant system as glutathione peridoxase activates thyroid hormones - Keshan disease reduced thyroid hormone

Chromium- enhance insulin action - glucose intolerance
Fluride- increase resistance tooth enamel - dental risk
Molybdenum- cofactor several enzyme- unknown

30
Q

iron functions, risks, sources

A

Iron - hemoglobin, respiration, immune, cognitive development, energy metabolism -fatigue anemia

RISK - children, pregnant

Meat, seafood, eggs, fortified

31
Q

other

A

the rest are rare
iodine - if not fortified
selenium if not in soil

32
Q

2 types iron

A

Ÿ Heme iron (ferrous iron): Fe2 +, found in hemoglobin and myoglobin of animal
fleshNon-heme iron (ferric iron): Fe3 +, iron found in plant foods, grains, supplements
(supplements can also come in the ferrous form), some minor amounts in meat
Ÿ Iron cookware can also contribute to iron intake (important source for
populations in developing countries, or when dietary iron sources are scarce)
Ÿ In humans: Fe2+ for absorption, Fe3+ for transport

33
Q

factors effect bioavalibility

A

Bioavailability
Plants sources (in Fe3+ ) contain factors interfering with iron absorption, even in iron
enriched products:
Ÿ Phytic acid, oxalic acid, polyphenols, excess fibre
Ÿ Meat, fish, HCl and ascorbic acid enhance
non-heme iron absorption when consumed
together => conversion to Fe2 + for adequate absorption

34
Q

Zinc toxicity

A

Toxicity
• Anorexia, nausea, vomiting, intestinal cramps, diarrhea
• Reduced Cu bioavailability (metallothionein); competition
with Fe absorption
• Impaired immune function

35
Q

Zinc Deficiency

A

ZINC REQUIREMENTS
Deficiency
• Anorexia (= loss of appetite)
• Dermatitis, impaired vitamins A, D and thyroid hormone
function, alopecia, poor wound healing
• Delayed growth, poor development in children
• Decreased taste
• Decreased immune function
Note: alcohol excess intake increases Zn requirement for its
metabolism (alcohol dehydrogenase) + increases excretion
via urine

36
Q

Zinc Functions

A

1) Zn is a cofactor to over 300 enzymes
- From every enzyme class (oxidoreductases, hydrolases, lyases, isomerases,
transferases, and ligases)
- Zn Binds amino acid residues and stabilizes the enzyme’s tertiary structure, and/or
- Zn Participates in the reaction at the catalytic site
- Zn-dependent enzymes are involved in:
o Protein, carbohydrate, lipid, nucleic acid and alcohol metabolism
o Growth and development
o Immune response
o Antioxidant defence
o Neurological function
o Reproductive function
2- Zinc is a cofactor to transcription factors
• Over 2,000 transcription factors require zinc
• The binding of zinc to transcription factors
results in a conformational change that
resembles a “finger”
• Zinc fingers interact with metal response
elements (MREs) located in the promoter
region of genes to enhance or repress
transcription
• The nuclear receptors that bind estrogens,
thyroid hormones, vitamin A and vitamin D
are examples of zinc finger proteins
• => Decreased thyroid hormone and BMR
observed in zinc-restricted diets
nc

37
Q

Zinc cofactor Enzymes

A

Alcohol dehydrogenase: alcohol
• Converts alcohol to acetaldehyde; also converts retinol to retinal
• Contains 4 zinc atoms per enzyme – 2 involved in catalytic activity, 2 stabilise protein structure
Carboxypeptidases A and B: protein digestion
• Secreted by pancreas and involved in protein digestion
• Enzymatic activity decreases with zinc deficiency => poor protein digestion
Polyglutamate conjugase: folate digestion
• Catalyses the removal of glutamic acids from folate => poor zinc status can diminish folate
absorption
Superoxide-dismutase: antioxidant
• Catalyses the removal of superoxide radicals: 2O2• + 2 H+ → H2O2 + O2
• SOD1 and SOD3 are zinc and copper dependent: Zn plays a structural role, Cu is catalytic
Matrix metalloproteinases: wound healing
• Degrade components of the extracellular matrix to allow for remodelling of extracellular
matrix proteins and tissue repair
• Zinc located at the catalytic site where the substrate binds

38
Q

Iodine deficiency

A

Deficiency
Iodine deficiency disorders (IDD) = goiter
and neurological cretinism
Goiter: when T4 level drops, increased TSH
secreted, thyroid enlarges to trap more
iodine;
Low T3 =>slowed metabolism
Neurological cretinism: irreversible mental
retardation, loss of hearing & speech
abilities, short stature, neurological disorder,
muscle spasticity in the future child.
Occurs when the mother is deficient in
iodine during pregnancy, breastfeeding, or
when deficiency is maintained during early
childhoodHypothyroidism in adults:
Effects of hypothyroidism are more
subtle in the brains of adults than
children: low educability, apathy, and
reduced work productivity.
Other symptoms: fatigue, weight gain,
cold intolerance, constipation.
WHO’s mission was to eradicating iodine
deficiency in the decade to 2020 (fortified
salt, iodine oil, & fortified milk interventions)

39
Q

Iron Toxicity

A

Toxicity
• Nausea, vomiting, stomach irritation,
impaired absorption of other minerals
• Hemochromatosis: genetic disorder where
the “mucosal block” (ferritin storage) does
not function adequately
• Ferroportin is not regulated: despite
high iron level, more is exported to the
blood and taken to tissues
• Iron deposits and overload in liver, heart
• If not managed, leads to liver cirrhosis,
heart failure, elevated oxidative stress
markers
• Management includes: regular blood
“letting”, dietary advice to reduce high iron
containing foods, chelation therapy

40
Q

iron deficiency

A

Deficiency • Iron-deficiency anemia = microcytic hypochromic anemia
(decreased hemoglobin); decreased hematocrit (% blood
volume containing RBCs), decreased serum ferritin*,
transferrin receptors number on cells increases
• Symptoms: shortness of breath, fatigue with usual tasks,
compromised immunity, depression, spoon
-shaped nails
• Most common minor mineral deficiency worldwide • At risk: premature infants, children, child-bearing age
women, vegetarians & vegans, regular blood donors,
gastric ulceration
• If during growth and development: impaired cognitive
development that may be irreversible
•
Symptoms may be few initially when diet is changed (e.g.
limiting iron sources) =>
iron stores are being used up

41
Q

functions of iron

A

1- Oxygen delivery
Hemoglobin: Found in red blood cells,
transports O2 and CO2, 4 x Fe-containing heme
groups which bind 1 oxygen each
Myoglobin: found in skeletal and cardiac
muscle, stores O2 , 1 x Fe-containing heme
group binds 1 oxygen
2- Oxidation – reduction reactions
=> Can be harmful in high concentration, as
iron forms free radical compounds
Fe2+ + H2O2 Fe3+ + OH- + •OH (hydroxyl radical)
3- Immune function
required for lymphocytes and natural killer cells
production
4- Iron-containing metalloenzymes
What are some examples you have come across?
5- Energy metabolism
Involved in the first steps of the CAC and as cofactors
of cytochromes in the electron transport chain
6- Alcohol and drug metabolism
Hepatic cytochrome p450 detoxification system
enzymes and catalase require iron as co-factors
7- Neurotransmitter synthesis
Cofactor in enzymes involved in synthesis of dopamine,
epinephrine, norepinephrine, serotonin

42
Q 
WHat do 
DMT1 HPC1 do
Ferrireductase 
Ferritin 
Feroportin 
Hepicidin 
Hephaestin Ceruloplasmin 
Transferrin 
Lysosomes
A

Small Intestine Fe2+ DMT-1 and HCP-1 (1st enter the)
Brush Boarder Ferrireductase converts fe3+ to Fe2+ (reductase REdUE 3 to 2)
Mucosal block = Ferritin: prevents excess absorption binds and stores iron in
enterocytes (and other tissues)
Ferroportin= transport iron out (trnasPORTIN)
Hepcidin regulates (regulates everything only one not F)
Convert fe2+ to fe3+ (oxidise) Hephaestin in
enterocytes and ceruloplasmin in the
blood
Transported as Fe3+ bound to Transferrin (TRANSFER after transPORT)
uptake endocytosis lysosomes release iron and transferren is recycled

43
Q

Describe absorption of iron from absorption to transportation

A

Absorption
• As Fe2+ in small intestine, mediated by carrier
proteins (DMT-1 and HCP-1)
• Efficiency depends on body’s iron status
(average 18%; range 14 - 40%)
• HCl in stomach and vitamin C enhance absorption
by conversion of Fe3+ to Fe2+ form
Ferrireductase: enzyme in the brush-border also
converts Fe3+ to Fe2+
Excessive intake of calcium, zinc, phosphorus,
manganese may chelate iron and interfere with its
absorption

Storage/carrier proteins in the
enterocyte
• Ferritin: binds and stores iron in
enterocytes (and other tissues)
• Iron does not enter bloodstream if
body’s iron stores are high
• Ferritin prevents excess absorption
=> “mucosal block”
Ferroportin: transports iron out of
enterocytes when supplies are low
for release into the blood
• Hepcidin: regulates how much iron
is released into the circulation
Ferroxidase enzymes: Hephaestin in
enterocytes and ceruloplasmin in the
blood (both copper-dependent
metalloenzymes) convert Fe2+ to Fe3+
• Transported as Fe3+ bound to transferrin
• In tissues cells: uptake by endocytosis;
lysosomes release the iron, and
transferrin is recycled

NUTR2101 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions