Nutrition: Vitamins and Minerals Flashcards Preview

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Flashcards in Nutrition: Vitamins and Minerals Deck (127):
1

What are the two water soluble vitamins?

b and c

2

Water soluble vitamins are excreted once concentration surpasses the ____ ____

renal threshold

3

Metabolic stores labile, depletion occurs in weeks or months. Deficiencies show up quickly on inadequate diet. True or false?

true

4

B-complex and vitamin c are not stored in the body and must be replaced everyday. True or false?

true

5

Thiamin (B1) is is rapidly converted to ____ ____ and ____ ____

thiamine pyrophosphate; thymine triphosphate

6

A symptom of thiamine deficiency is loss of appetite, constipation, nausea, mental depression, fatigue - this set of symptoms is referred to as ____-____ syndrome

Wernicke-Korsakoff

7

Severe thiamin deficiency leads to beriberi disease. What type of population is this seen with?

population that rely on polished rice and alcoholics

8

Dry beriberi can cause ____ ____ and it is considered wet beriberi when coupled with _____

muscular dystrophy; edema

9

Both forms of beriberi lead to ___ failure

heart

note: coffee and tea destroy thiamin

10

Riboflavin (B2) is a recourse of ____ and ____ - both are coenzymes

FAD; FMN

11

Riboflavin is required for ___ mobilization so deficiency contributes to anemia

iron

12

Symptoms of Riboflavin deficiency include?

scaly dermatitits, glossitis

note: chronic alcoholism can lead to deficiency

13

_____ slows conversion of riboflavin to FMN and FAD

hypothyroidism

14

Niacin (B3) is not a vitamin in strict sense - it can be synthesized from ____

Trp

60 mg Trp -> 1 mg Niacin..... not very efficient

15

What does Trp require to synthesize Niacin?

pyridoxine, riboflavin, and iron

16

Dietary niacin and niacinamide are converted to ___ and ___

NAD; NADP

17

Deficiency of Niacin causes ____ of tongue

glossitis (redness)

18

The disease associated with Niacin deficiency is pellagra. What three D's are seen with pellagra?

dermatitis, diarrhea, dementia

19

Pyridoxine, pyridoxamine, and pyridoxal are naturally occurring forms of vitamin ___

B6

20

Pyridoxine is required for the synthesis of what NTs?

serotonin, NE, Epi, GABA

note: also required for myelin formation

21

Deficiency of pyridoxine causes what symptoms?

irritability, nervousness, and depression in mild deficiency

convulsions in severe deficiency

22

____ is covalently bound to an amino group of lysine residue in carboxylase of pyruvate, acetyl-CoA, and propionyl-CoA

biotin

23

Where is biotin found and synthesized?

found in peanuts, chocolate, and egg

synthesized by intestinal bacteria

24

Folic acid in diet usually occurs as _____ derivatives with 2 to 7 ___ acid residues joined in gamma-peptide linkages

polyglutamate; glutamic

25

What enzyme removes extra glutamate in the intestine?

folypoly-gamma- glutamate carboxylase II

26

The monoglutaminated folic acid is taken up by reduced folate carrier into what cells?

intestinal mucosa

27

Folate deficiency inhibits what?

DNA synthesis by decreasing availability of purine

note: neural tube birth defects, cervical and colon cancer

28

Vitamin B12 contains ___ and its derivatives

B12

29

B12 deficiency results in accumulation of both ____ and ____ acid

homocysteine; methylmalonic

30

In foods, B12 is bound to proteins in the ____ or ____ form

methyl; 5'-deoxyadenosyl

note: must be released from protein by hydrolysis in the stomach or trypsin digestion in the intestine

31

A Cobalamin (B12) deficiency causes what?

pernicious anemia with neurological deterioration caused by demyelination of nervous tissue

32

Vitamin C is a cofactor for oxidases involved in what?

hydroxylation of lysine and proline, synthesis of carnitine, and NE

33

Hydroxylation of Lys and Pro is required for ____ to cross-link properly

procollagen

34

Vitamin C is required for maintenance of normal CT and for wound healing, and bone formation. true or false?

true

35

Ascorbic acid-water soluble vitamins (vitamin C), when dysfunctional, cause the most severe symptoms of ____

scurvy

36

____ may act as an antioxidant against oxidative stress

ascorbate

37

How does scurvy present?

formation of brown spots on skin, spongy gums, and bleeding from all mucous membranes

38

What is the time from for onset of scurvy symptoms?

1-6 months depending on vitamin C storage level in body to begin with

39

Ascorbic acid is required for a range of essential metabolic reactions and is absorbed by both ____ ____ and ____ diffusion

active transport; simple

40

Without ____ ____, gums would bleed because blood vessels need collagen and teeth would fall because they depend on collagen for their attachment to the gingiva

ascorbic acid

41

What are the fat soluble vitamins?

Vitamins A, D, E, and K

42

Retinol, retinal, and retinoid acid are the active forms of vitamin ___

A

43

Precursors of vitamin A are synthesized by plants as ____, some are cleaved to retinol and stored in the liver as ___ ____

carotenoids; retinol palmitate

44

Liver, yolk, butter, and milk are good sources of ___; ____ are found in dark green and yellow veggies

retinol; carotenoids

45

At low oxygen tensions, ___-___ is very effective antioxidant against cancers initiated by free radicals

beta-carotene

46

In addition to direct role of vitamin A in visual cycle, carotenoids lutein and zeaxanthin reduce the risk of ___ ____

macular degeneration

47

Retinyl phosphate is required for synthesis of glycoproteins. This is an important component of ___

mucus

48

Retinol and/or retinoid acid down regulate the synthesis of ___

keratin

49

Retinol and/or retinoid acid are required for the synthesis of iron transport protein ___

transferrin

note: thus vitamin A deficiency can lead to anemia

50

Night blindness is an early symptom of vitamin ___ deficiency

A

51

Severe deficiency of vitamin A leads to progressive keratinizaiton of the cornea, known as ____

xerophthalmia

52

Vitamin A accumulates in the liver where it can become toxic. What are some of the symptoms?

bone pain, scaly dermatitis, enlargement of liver and spleen, nausea, and diarrhea

53

Vitamin D is a group of fat-soluble vitamin responsible for enhancing what?

intestinal absorption of calcium, iron, magnesium, phosphate, and zinc

note: D2 and D3 are most important

54

Vitamin D is synthesized in the skin from ___ from sun

cholesterol

55

In the liver, D3 is converted to ____; D2 is converted to ____

calcidiol; 25-hydroxyvitamin D2

56

Part of the calcidiol is converted by the kidneys to ___, the biologically active form of vitamin D

calcitriol

57

Calcitriol circulates as a hormone in the blood, regulating what?

concentration of calcium and phosphate in the blood stream and promoting the healthy growth and remodeling of bone

58

Insufficient sun exposure causes ____ which is softening of the bones

osteomalacia (rickets in children)

note: can be from deficiency in calcium, phosphorus, or vitamin D

59

Vitamin D toxicity causes hypercalcemia. What are the main symptoms?

anoxrexia, nausea, vomitting, weakness, renal failure

note: mental retardation can be seen in young children along with abnormal bone growth

60

___ is the continued formation of osteoid matrix and cartilage that are improperly mineralized resulting in soft liable bones. ____ is demineralization of preexisting bones

Rickets; osteomalacia

61

In regards to osteomalacia and osteoporosis, osteoid matrix remians intact in ___ but not in _____

osteomalacia; osteoporosis

62

Vitamin E occurs as tocopherols and tocotrienols, which are ____

antioxidants

63

alpha-tocopherol is potent against what?

ROS

64

gamma-tocopherol is potent against what?

Reactive nitrogen species

65

Tocopherols and tocotrienols also prevent oxidation of LDL which does what?

reduces risk of cardiovascular disease

66

In regards to Vitamin E deficiency, what type of symptoms can occur with prolonged deficiency associated with malabsorption disease

neurological

67

True or false? Vitamin E can act as an anticoagulant, increasing the risk of bleeding problems.

true

68

In combination with certain drugs such as ___, hypervitaminosis E can be life-threatening. It may also counteract vitamin ___, leading to a deficiency

aspirin; K

69

Vitamin K occurs as K1 in ___ vegetables and K2 in ____ bacteria

green; intestinal

70

Vitamin K is required for the conversion of ____ acid to __-___ acid

glutamic; gamma-carboxyglutamic

71

gamma-carboxyglutamic acid residues are good ___ and allow the proteins to bind ___ required for their biological activity

chelators; Ca2+

72

In carboxylase reactions, the active hydroquinone form of vitamin K is converted to what?

inactive 2,3 epoxide form

note: regeneration requires K epoxide reductase

73

Vitamin K is essential in blood ___

coagulation

note: this is why deficiency causes increased coagulation time

74

Where do vitamin K1 and K2 accumulate?

K1: liver
K2: peripheral tissues

75

The most common vitamin K deficiency occurs in which individuals

newborn infants and in patients with obstructive jaundice and diseases leading to malabsorption and long-term antibiotic therapy

76

This is the most abundant mineral in the body. Mostly in bone, small amount outside of bone functions in a variety of essential processes

Ca2+

77

Low serum Ca2+ stimulates formation of what?

1,25-dihydroxycholecalciferol - enhances intestinal Ca2+ absorption

78

Vitamin __ is required for optimal utilization of calcium

D

79

True or false? exercise facilitates calcium utilization for bone formation

true

80

Symptoms of Ca2+ deficiency resemble those of vitamin __ deficiency

D

81

Bone density reaches its maximum between what years?

10-35

82

This mineral is required for many enzyme activities, particularly those utilizing an ATP complex and for neuromuscular transmission. This mineral is significantly reduced during processing of food items.

Magnesium

83

Deficiency of Mg2+ occurs in _____, with use of certain diuretics and metabolic acidosis

alcoholism

84

The main symptoms of Mg2+ deficiency are what?

weakness, tremors, and cardiac arrhythmia

85

Supplemental Mg2+ can help prevent formation of calcium oxalate ___ in the kidney

stones

86

Iron is a component of ___ in hemoglobin and myoglobin, which are essential for O2 transport

heme

87

Total body iron in human adults is __-__ g. Erythrocytes normally live only ____ days; meaning erythrocytes containing 20 mg of iron are destroyed each day

3-4; 120

88

The net loss of iron for males and postmenopausal women is shedding of intestinal and skin cells, which amounts to about __-__ mg/day

1-2

89

Assuming a 10-15% efficiency of Iron absorption, an RDA of ___ mg/day for normal adult males and ___ mg/day for menstruating females has been set. For pregnant females, it is ___ mg/day

8; 18; 27

90

Patients develop ____ degeneration and ___ due to increased iron in the pancreas and brain

retinal; diabetes

91

_____ is primarily a genetic disease of iron overload. Patients with this disease develop iron deposits in the liver, heart, and endocrine tissue even though they have normal intakes of dietary iron.

hemochromatosis

92

Treatment for hemochromatosis consists of regular ___, which is effective at preventing the symptoms of hemochromatosis if started early enough. People with hemochromatosis are also advised to avoid foods and supplements containing high levels of iron or vitamin ___

phlebotomy; C

93

There are a number of clinical tests that can be used to determine iron status. What is the normal range for males and females for hemoglobin?

males: 13.8-17.2 gm/dl
females: 12.1-15.1 gm/dl

94

What is the normal hematocrit range for males and females?

males: 36.1-44.3%
females: 40.7-50.3%

note: hematocrit is % of RBCs found in whole blood

95

Iron-deficiency anemia is characterized as _____ _____ anemia, meaning that the RBCs are smaller and paler than normal due to their decreased hemoglobin content

microcytic hypochromic

96

Dietary iodine is efficiently absorbed and transported to the ___ gland

thyroid

97

Thyroid hormones function in regulating what?

basal metabolic rate of adults and the growth and development of children

98

____ fish are the best natural food sources of iodine and in the past population groups living in inland areas suffered from the endemic deficiency disease called ___

saltwater; goiter

99

____ is part of the catalytic center of over 300 metalloenzymes, including RNA and DNA poly

zinc

100

Zinc fingers provide what to proteins?

structural stability and are also important for protein-protien interactions (signal transduction)

101

Relatively large amounts of loosely bound zinc are also found in vesicular structures including?

synaptic vesicles of nerve terminals and cells of islets of langerhans

102

Intracellular zinc levels are controlled in part by a group of 14 transporters called ____ which transport zinc into cells and 10 transporters called ____ which control the efflux of zinc from the cytosol to extracellular space

ZIPs; ZnTs

103

Zinc deficiency in children is usually marked by what?

poor growth and impairment of sexual development; also poor wound healing and dermatitis

104

Zinc is present in ____, a salivary polypeptide that appears to be necessary for normal development of taste buds

gustin

105

Zinc is required for ___ production by monocytes and T cells

cytokine

106

In lead poisoning, lead replaces the zinc which leads to ____

anemia

107

Severe zinc deficiency is seen primarily in ____ patients with chronic renal disease

alcoholic

108

The most characteristic early symptom of zinc-deficient patients on long term parenteral nutrition (TPN) is ___

dermatitis

109

Ceruloplasmin and hephaestin are important copper-containing enzymes that do what?

oxidize iron to facilitate its binding to transferrin

110

Dopamine beta-hydroxylase is an important copper-containing enzyme that does what?

NE synthesis

111

Lysyl oxidase is an important copper-containing enzyme that does what?

collagen cross-linking

112

Tyrosinase is an important copper-containing enzyme that does what?

pigment formation

113

anemia, hypercholesterolemia, demineralization of bones, leukopenia, fragility of large arteries, and demyelination of neural tissue are all symptoms of what?

copper deficiency

114

Copper deficiency is relatively rare and is usually only seen because of excess ___ intake

zinc - zinc and copper compete for absorption

115

____ disease is an x-linked disorder characterized by global copper deficiency

Menkes

116

What mutation causes Menkes disease?

ATP7A copper transporter - interferes with the ability of intestinal mucosal cells to transport copper into the bloodstream

117

What are the symptoms of Menkes disease?

mental retardation, growth retardation, hypothermia, loos skin and joints, hypo pigmentation, and kinky hair

118

____ disease is an autosomal recessive disease characterized by copper overload, particularly in the liver and the brain

Wilson

119

What mutation causes wilson's disease?

ATP7B copper transporter that prevents the liver and neurological tissue from getting rid of excess copper

120

What are the signs of Wilson's disease?

liver failure, seizures, psychiatric symptoms, characteristic gold-brown ring called the Kayser-Fleischer ring around the periphery of the cornea

121

____ is a component of the low-molecular-weight protein chromodulin which potentiates the effects of insulin by facilitating insulin binding to its receptor and receptor kinase signaling

chromium

122

The chief symptom of chromium deficiency is what?

impaired glucose tolerance, a result of decreased insulin effectiveness

123

Selenium is one of the few nutrients not removed by the milling of flour and is usually though to be present in adequate amounts in the diet. True or false?

true

124

Selenium supplementation may reduce the risk of what cancers?

lung, breast, and bladder

125

____ is a component of arginase, glutamine synthetase, Mn superoxide dismutase, and phosphoenylpyruvate decarbyxlase and activates a number of other enzymes

mangansese

126

______ is present in xanthine oxidase

molybdenum

127

____ appears to be important for bone formation, nerve function, and immune response

boron