Nutrition Flashcards
1
Q
What are vitamins?
A
Small organics used as coenzymes
2
Q
How much vitamins are required?
A
µg to mg
3
Q
What are minerals?
A
Inorganic elements
4
Q
How much minerals are required?
A
µg to g
5
Q
What percentage of the population are satisfied by the RNI?
A
97.5
6
Q
What are the water soluble vitamins?
A
Vitamins B1-B12, Vitamin C
7
Q
What is Vitamin B1?
A
Thiamin
8
Q
What is B2?
A
Riboflavin
9
Q
What is B3?
A
Niacin
10
Q
What is B5?
A
Panthothenic Acid
11
Q
What is biotin?
A
B7
12
Q
What is Pyridoxine?
A
B6
13
Q
What is B12?
A
Cobabulim
14
Q
What is B9?
A
Folic Acid
15
Q
What is thiamin used for?
A
Thiamin pyrophosphate in pyruvate decarboxylase and α-ketogluterate dehydrogenase
16
Q
What does B1 deficiency cause?
A
Beri Beri disease
Muscle weakness, nerve damage and heart failure
17
Q
What is riboflavin used for?
A
FAD/FMN cofactors
18
Q
What is B3 used for?
A
Nicotinamide coenzymes
19
Q
What does B3 deficiency cause?
A
Pellegra: dermatitus, diarrohea, depression and death.
20
Q
What can B3 be synthesised from?
A
Tryptophan in low levels
21
Q
How can Pellegra be treated?
A
Pharmacological doses of niacin to lower LDL and trigylcerides, nicotinamide to improve skin and neurological disorders
22
Q
What do prolonged high doses of niacin cause?
A
liver damage
23
Q
How common is Pellegra?
A
Rare except for in eating disorders
24
Q
What is B5 used in?
A
Acetyl CoA
25
Is Panthothenic acid deficiency common?
No
26
What is biotin used for?
Added to 4 carboxylases by holocarboxylase synthase
| Incorporated into Histones
27
How is biotin recycled?
Via biocytin by the biotinidase enzyme
28
How much biotin is incorporated into histones?
29
How is Pyridoxine used?
PLP cofactor
30
What enzymes use PLP?
```
~100
Transaminases
Glycogen breakdown
neurotransmitter synthesis
haem synthesis
modulation/antagonists of steriod hormones
```
31
How common is B6 deficiency?
Poor intake is common
32
What does excess Pyridoxine cause?
Permanent nerve damage
33
What structure does B12 have?
Porphyrin ring with cobalt III ion
34
What is cobabulim used for?
methionine synthase
| L-methylmalonyl CoA mutase
35
What is pernicious anaemia caused by?
Inability to absorb B12
autoimmune attack or in elderly
Lack of intrinsic factor to transport from from duodenum
36
How is B12 absorbed?
Bound in stomach by R factor
Degraded in duodenum/small intestine
Bound by intrinsic factor for absorption
37
What is B12 deficiency?
Macrocytic anaemia and neurological problems caused by disruption of myelin and inflammations
Raised homocysteine and CVD
38
Where is B12 found?
Animal food sources
39
What is the structure of Folic acid?
PABA
Glutamate
Pteridine ring
40
What does B9 do?
Transports interconvertable 1C units for biosynthesis of Serine, Methionine, Glycine, Choline, Purines and dTMP
41
What does Folate deficiency cause?
```
Megaloblastic anaemia (large immature RBCs)
neural tube defects (no RBC growth or cell division)
Macrocytic anaemia
```
42
Why does B12 deficiency cause macrocytic anaemia?
B12 required to convert homocysteine to methionine for folate recycling.
Can mask B9 deficiency
43
What does the B9/B12 pathway control?
dTMP synthesis
DNA methylation
Protein synthesis
44
Which part of B12/B9 pathway can be targetted by anticancer drugs?
dTMP synthesis
45
What is vitamin C?
Ascorbic acid
46
What is Vit C used for?
Cofactor for prolyl and lyslyl hydroxylases to act after translation to stabilise structure
Adrenaline, bile acid, collagen synthesis
47
What is Vitamin C deficiency?
Scurvy
48
What are the symptoms of vitamin C deficiency?
Skin, gum disease
| Weak collagen for healing, bones and muscle
49
How common is Scurvy?
Affects 25% of low economic population and elderly
50
Which vitamins have antioxidant properties?
Vitamins C A and E
51
What are the fat soluble vitamins?
Vitamin A D E K
52
When is vitamin E deficiency found?
In rare digestive disorders
53
Where is vitamin a found?
In diet as β-carotene
54
What is vitamin A used for?
antioxidant
retinol for converted between cis and trans in vision cycle
retionic acid binds to RXR receptors for cell differentiation and proliferation
55
What does vitamin A deficiency cause?
Blindness
| Increased CVD and cancer due to antioxidants
56
What does excess vitamin A cause?
foetal malformations- teratogenic
57
What evidence is there that antioxidants prevent CVD and cancer?
Massachesetts review showed reduced disease in elderly people
Cochrane review of 78 studies showed potential mortality of overdose
58
Where is vitamin K found?
Phylloquinone in plants
| menaquinone in intestinal bacteria
59
What is vitamin K used for?
conenzyme for carboxylation of γ-Glutamate for to bind Ca in clotting factors 2,7,9,10
60
How does warfarin inhibit Vitamin K cycle?
Blocks regeration by reduction using a disulphide bond
61
How is vitamin D synthesised?
7-dehydrocholesterol
cholecalciferol (skin/UV)
25-hydroxyvitamin D3 (Liver)
1,25-dihydroxyvitamin D3 (Kidney)
62
What is another name for vitamin D3?
calcitrol
63
What is the function of vitamin D?
```
Transcriptional activation of 200 genes
Regulation of Ca/P
Cell cycle regulation
Immune system
Skeletal muscle function
```
64
What does Vitamin D deficiency cause?
Osteomalacia/Ricketts
| Potential link to cancer
65
How can vitamin D deficiency be caused?
```
autoimmune diseases
geographical location
age
racial factors
genetic factors
```
66
What are minerals used for?
Coenzymes or prostethic groups of enzymes
67
What is Iron used for?
Electron carriers in cytochromes
| Oxygen carriers in haems
68
What is the main cause of iron deficiency anaemia?
Poor absorption
69
How is iron absorbed?
From animal sources using a Hepcidin controlled transporter
70
What are the symptoms of iron deficiency anaemia?
Microcytic hyperchromic RBCs
71
Which mineral deficiencies are most common worldwide?
Iron and Iodine
72
How is Calcium deficiency reduced?
Addition to flour by law
73
What is calcium used for?
```
Neurones
secretion
muscles
cytoskeleton
signalling
bone mineralisation
coagulation
```
74
What does hypocalcaemia cause?
Tetany
| Osteoporosis
75
How is [plasma calcium] controlled?
Detected by Pituitary to release Parathyroid hormone
Release from bones, increased reabsorption, stimutlation of Vitamin D release
and Vitamin D increases gut uptake, stimulates PTH release and sensitises bone to PTH
76
How is iodine absorbed?
Absorbed from blood by NA+ symport into thyroid follicle
combines with thyroglobulin
cleavage into inactive thyroxine and active triiodothyronine in epithelium
77
What does iodine deficiency cause?
Cretinism from pregnancy (mental and physical growth retardation)
Giotre in adults
78
What is iodine used for?
Thyriod hormone production only
79
What does excess vitamin C cause?
kidney stones
