Nutritional Biochem 2 Flashcards
(115 cards)
1
Q
Essential organic substances in minute amounts
A
Vitamins
2
Q
Three distinctive characteristics of VItamins
A
Organic compounds:
◦Contain C, H, O
◦Only water soluble has N
◦Some have S and Co
3
Q
substances that interfere with the normal functioning of a vitamin
A
Antivitamins or vitamin antagonists
4
Q
man-made or synthesized in the laboratory
A
Synthetic vitamins
5
Q
multiple forms of a vitamin
A
Vitamers
6
Q
substances that have physiological roles like vitamins but they are present in larger amounts and partially synthesized in the body
A
Vitamin–like compounds
7
Q
too much or too little unhealthy
A
Vitamin malnutrition
8
Q
result of lack of vitamin, later stage -> more defined signs and symptoms
A
Avitaminosis
9
Q
vitamin toxicity due to excessive accumulation in the body
A
Hypervitaminosis
10
Q
4 fat soluble vitamins
A
ADEK
11
Q
11 water soluble vitamins
A
◦C (10) B-complex ◦B1: Thiamin ◦B2: Riboflavin ◦B3: Niacin ◦B5: Pyridoxine Cobalamin Pantothenicacid Folic acid Biotin Choline Inositol
12
Q
Old names of Vitamin A
A
antixerophthalmic vitamin,
anti-infective vitamin,
opthalmin,
axerophtol
13
Q
Preformed vit A
A
Retinoids (retinal, retinol, retinoic acid)
14
Q
Provitamin A
A
◦Carotenoids
◦Must be converted to retinoid form
15
Q
required for structural components of eye
A
Retinoic acid
16
Q
turns visual light into nerve signals in retina of eye
A
Retinal
17
Q
is necessary for cellular differentiation
-Important for embryo development, gene expression
A
Retinoic acid
18
Q
Deficiency of this vit leads to decreased resistance to infections
A
Vitamin A
19
Q
◦Irreversible blindness
◦Follicular hyperkeratosis
◦Poor growth
A
Xerophthalmia
20
Q
foamy, soap sud-like spots on the conjunctiva
A
Bitot`sspot
21
Q
dry, hazy and rough appearing cornea
A
Corneal xerosis
22
Q
crater-like defect on the cornea
A
Corneal ulcer
23
Q
Softened cornea; sometimes bulging
A
Keratomalacia
24
Q
the “Sunshine vitamin” which acts as a steroid hormone
Anti-rachitic or ricket preventive vitamin
A
Vitamin D (Calciferol)
25
Precursors of vit D in plants
Ergosterol
26
Precursors of vit D in animal's lipids
7-dehydrocholesterol
27
SOURCES OF VITAMIN D
fish liver oils (sardines, salmon and herring)
| Fortified dairy and dairy products
28
Poor sources of vit D
Human milk and unfortified cow’s milk
29
___ Enhances vitamin D absorption
Dietary fat
30
25-Hydroxyvitamin D3is also called _____. (predominant in circulating metabolite)
calcidiol
31
1,25-Dihydroxyvitamin
D3 is also called _____.
(the most active form)
calcitriol
32
Facilitates the absorption of calcium during low dietary calcium intake
Vit D
33
Ca binding protein
Calbindin
34
Maintenance of calcium and phosphorus homeostasis
Vit D
35
acts as a hormone binding VDR (vit D receptor proteins) in the nucleusregulates gene expression
calcitriol
36
Vitamin D Deficiency: syndrome (abnormal muscle twitching, cramps, spasms in the wrists and joints)
Tetany
37
Vitamin D Deficiency in children
RICKETS
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Vitamin D Deficiency in adults
OSTEOMALACIA
39
A disease involving impaired mineralization of the bone
bone pain, muscular tenderness, hypocalcemic tetany
enlargement of the epiphyses of the long bone and rib cage, bowing of the legs, bending of the spine and weak and toneless muscles
RICKETS, Knock knees, Rachitic rosary
40
(more than 25 μg/day (infants & small children) and 50 μg/day (adults)
◦elevated serum calcium and phosphorus, calcinosis of kidney, lungs, ear
Hypervitaminosis D
41
Signs of Excessive Vitamin D Toxicity
Excessive calcification of bone
Kidney stones
Hypercalcemia
Headache
42
Anti-sterility Vitamin
Vitamin E
43
Other name of Vitamin E
Tocopherols(to bear child) and tocotrienols
44
Unit of Measure unit of measure of vitamin E
α–tocopherol equivalents (α-TE)
1 mg α-tocopherol= 1 α-TE
◦Beta = x 0.5
◦Gamma = x0.1
45
SOURCES OF VITAMIN E
Plant products (especially oils): raisin bran, almonds, sunflower oil, canola oil, corn oil, soybean oil, asparagus, peanuts
46
Enhances vit e absorption
dietary fat
47
Readily decompose vitamin E
| Oxidation is enhanced in the presence of Pb, Fe, Cu, salts and alkali
U.V. exposure and Oxygen
48
Reduces vitamin E potency
Rancid Fat
49
Amount of Vitamin E ingested
Only 20-30% of ingested vitamin E is absorbed
50
Most important lipid-soluble antioxidant in the cell (cellular antioxidant defense system
VITAMIN E
51
- Prevents the oxidation of polyunsaturated fatty acids
| - Reduces the risk of heart disease by protecting LDL against oxidation
VITAMIN E
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◦Selenium containing enzyme
◦Helps breakdown peroxidized fatty acids (that tends to form free radical)
◦Lessen the burden of vitamin E
Glutathione peroxidase
53
◦Reacts with peroxide and single oxygen (free radicals)
| ◦Reduce free radical activity
Superoxide dismutase and catalase
54
Vitamin E Deficiency
- Rare but it targets: neuromuscular, vascular and reproductive
- Cellular level: increase in oxidation of membranecell injury and necrosis
55
Vitamin E Toxicity
Least toxic , not largely stored in the body
◦Decreases the body’s utilization of other fat-soluble vitamins
◦may interfere with the function of vitamin K -> hemorrhage
“HypervitaminosisE”
56
Anti-hemorrhagic vitamin
Vitakin K
57
Naturally-occuring forms of vit K that is synthesized by green plants ; converted to K2
Phylloquinones(K1 series)
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Naturally-occuring forms of vit K that is synthesized by the intestinal bacteria
Menaquinones(K2 series)
59
Naturally-occuring forms of vit K that is twice as potent; metabolized more rapidly
Menadione(synthetic)
60
SOURCES OF VITAMIN K
High amounts in green leafy vegetables (broccoli, cabbage, turnip greens and dark lettuces)
Low in breastmilk
61
antagonizes the role of vitamin K
Anticoagulant drugs (e.g. Dicumarol)
62
Reduce vitamin K synthesis
Sulfa drugs and antibiotics
63
May destroy vitamin K
| Vitamin K is heat-stable
Light, oxidizing agents, acids, and alkalis
64
Essential for the synthesis of several proteins involved in blood clotting
Vitamin K
65
Needed for the synthesis of proteins involved in regulating bone growth and cell growth
◦Osteocalcin (requires vit K for its maturation)
Vitamin K
66
VItamin K is stable to heat, destroyed easily by light
| True or False
True
67
Vitamin K Deficiency in newborn
- hemorrhagic disease
| - Due to hypoprothrombinemia; could lead to fatal anemia
68
Vitamin K Deficiency in adults
delayed blood clotting time, increased incidence of hip fractures in older adults
69
What are the characteristics of Water Soluble Vitamins?
- Soluble in water
- Simple diffusion (large amount)
- Through a carrier-mediated process (smaller amounts)
- Distributed in aqueous phases of the cell
- Most are not stored in appreciable amounts
- Essential cofactors or co-substrates of enzymes involved in various aspects of metabolism
70
Ascorbic Acid
Vitamin C
71
◦Antiascorbutic vitamin
| ◦“fresh food” vitamin
Vitamin C
72
Biologically active forms of vitamin C
◦L-ascorbic acid
| ◦L-dehydroascorbic acid
73
vitamin C is most easily destroyed (heat, alkali, light, oxygen; Fe & Cu)
True or false
True
74
we cannot produce vitamin C because humans lack
gulonolactone oxidase
75
Highest amount of vit c in the body
liver, adrenal glands, and glandular organs)
76
FUNCTIONS OF VITAMIN C?
1. Antioxidant properties
2. Formation & maintenance of intercellular cementing substances
3. Wound healing & fracture healing
4. Collagen Synthesis
5. Promotes resistance to infection
77
translocates fatty acid from the cytosol to the mitochondria needed for fatty acid oxidation
Carnitine
78
needed to convert carnitine from trimethyllysine
Vitamin C
79
Peptide which act as hormones and hormone-releasing factors: oxytocin, cholecystokinin, gastrin
Amidated hormones
80
Rich and good sources of vit C
◦Plant: Fresh fruits (anonas, bayabas, datiles,cashew, strawberry, melon, papaya, camichile, citrus fruits, mangoes), broccoli, red bell pepper, tomatoes and GLV
◦Animal: kidney and heart
81
◦Legs in “frog’s position”
| ◦Flexing as a response to tender, painful, and swollen thighs, delayed dentition, and skeletal growth
Infantile scurvy
82
Effects of Excessive Vit C Intakes
* Gastrointestinal disturbances and diarrhea
* Increased possibility of forming renal oxalate and uric stones
* Can give a false positive urinary glucose test (Db test)
83
Vitamin C Promotes Fe absorption, but Fe can inhibit Cu absorption.
True or false
True
84
Vitamin C Prevents binding of Cu to metallothione in intestinal cells.
True or false
True
85
Vitamin C Prevents oxidation of tetrahydrofolate, Vit. A and PUFAs.
True or false
True
86
High Vit.C -> destroy B12.
| True or false
True
87
B1 coenzyme
TPP
88
B2 coenzyme
FAD FMN
89
B3 coenzyme
NAD/ NADP
90
B5 coenzyme
CoA
91
B6 coenzyme
PP
92
B12 coenzyme
5’ deoxyadenosylcobalamin
| Methylcobalamin
93
Biotin
Biocytin
94
Folate
tetrahydrofolate
95
VITAMIN B1 is also called
THIAMIN/Anti-Beriberi Vitamin
96
Stable in dry form and slightly acidic medium
| Sensitive to neutral or alkaline medium, sulfite treatment, high temperature and prolonged cooking
Vitamin B1/ Thiamin
97
TPP in GIT is hydrolyzed to ______.
thiamin
98
Vitamin B1 all are excreted into the _____.
urine
99
TPP is a coenzyme for three mitochondrial enzymes involved in the ____ ____ of ______.
oxidative decarboxylation of α-keto acids:
Pyruvate dehydrogenase complex
α-ketoglutarate dehydrogenase
Branched-chain α-keto acid dehydrogenase
100
1. The final common pathway for the oxidation of macronutrients
2. Major role in gluconeogenesis transamination, deamination, and lipogenesis
The TCA Cycle and TPP
101
a group of enzyme which catalyzes the oxidative decarboxylation of pyruvate to acetyl CoA
Pyruvate Dehydrogenase complex
102
enzyme that catalyzes in the oxidative decarboxylation of α-keto acids to yield succinyl CoA
α-Ketoglutarate Dehydrogenase
103
enzyme that catalyzes the oxidative decarboxylation of α-keto acids from valine, leucine and isoleucine
◦maple syrup urine disease: poor sucking, irregular respiration, periodic rigidity and seizures, appear after infants receive a protein-containing feed
Branched-chain α-ketoacid Dehydrogenase
104
TPP is a coenzyme for transketolase (found in the cytosol)
◦Transfer of two-carbon ketol unit from a donor molecule to an acceptor molecule in 2 transketolation reactions
True or false
True
105
* Nerve conduction: controls opening of chloride channels so it could act as a membrane stabilizer
* Nerve impulse transmission: deficiency of enzyme systems may lead to decreased synthesis of neurotransmitters (GABA, acetylcholine et al)
VItamin B1/Thiamin
106
Food Sources of VItamin B1/Thiamin
* Widely distributed, destroyed by heat, oxidation and ionizing radiation
* TPP: Lean pork, pork liver, pork glandular organs, liver and organ meats of other animals, egg yolk
* Free Thiamin: unpolished rice, whole grains, legumes, dried yeast, rice bran and wheat germ
107
DEFICIENCY OF THIAMIN Early stage:
◦Loss of appetite, weakness, easily fatigued, GIT disturbances (indigestion and severe constipation), poor reflexes, irritability, retarded growth, and numbness of extremities
108
DEFICIENCY OF THIAMIN Later stage:
◦Beriberi or Nutritional Polyneuritischanges in GI, cardiovascular, and nervous system
◦Infantile Beriberiin infants 2-5 months whose main nourishment is from a mother with beriberi
109
Type of beri-beri that has edema in the lower extremities which progresses to the body cavities (abdomen and chest); enlarged heart, arrhythmias, breathing difficulty
Wet Beriberi
110
Type of beri-beri that has muscle wasting, aphonia, whining cry, cyanosis, difficulty in breathing, may lead to death within a few hours.
Dry Beriberi
111
◦Seen in alcoholics (pregnant women with excessive vomiting)
◦Symptoms: short-term memory loss, mental deterioration, disorientation, abnormal perception, jerky eye movements, sudden heart failure if untreated
Wernicke-Korsakoff Syndrome
| - Vit B1/ Thiamin Deficiency
112
VITAMIN B2 is also called ____.
RIBOFLAVIN
113
Vit B2 or riboflavin is a component of coenzyme:
◦Flavin mononucleotide (FMN)
| ◦Flavin adenine dinucleotide (FAD) FADH2
114
Vitamin B2/ Riboflavin converts Tryptophan to ____.
Niacin
115
Helps maintain healthy skin, hair, nails, tongue, and mouth (Vitamin C)
Vit B2/RIBOFLAVIN
