Brainscape's Knowledge GenomeTM

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


See full index

Nutr 221 > Vit A > Flashcards

Vit A Flashcards

1
Q

initial transport of the fat soluble vitamins happens in the ___

A

chylomicron

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

There is no control on amount taken up for fat soluble vitamins because of ___cytosis

A

pino

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

what are the 3 forms of Vit A found in the body?

A

retinol, retinal, retinoic (and preformed vit A from animal foods–>retinol as retinyl ester)

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

only ___% of carotenes in foods are provitamin A

A

10; these are carotenes in plant-based foods

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

this provitamin A, when split in half, obtain 2 retinol

A

beta carotene

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

this provitamin A only forms one retinol

A

alpha-carotenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

examples of non provitamin A carotenes (provide no retinols)

A

lycopene (prostate cancer reduction) and lutein (role in eye)

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

what is the conversion factor for b-carotene –>retinol?

A

50 %

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

re-esterification prefers which fatty acid?

A

palmitate

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

what is the pathway of the chylomicron?

A

leave cell–>lymph–>blood–>liver

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

some retinal is converted to retinoic (irreversible) instead of retinol. Where does this go?

A

the blood

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

1 RAE = __ mcg retinol, ___ mcg beta carotene, __ mcg from b-carotene in supplements, ___ mcg from other provitamin carotenes

A

1; 12; 2; 24

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

holo-RBP needs ___ to transport retinol to sites of action

A

TTR (transthyretin)

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

zinc and amino acids are required to make and release this

A

apo-RBP

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

foods fortified with retinol in Canada

A

margarine, low fat milk, soy beverages

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

if the IU is from carotenes, to get RAE you divide by ___

A

20

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

if all carotene, 1 RE = ___ RAE

A

0.5

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

what is the DV of Vit A?

A

1000 RE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is rhodopsin?

A

11-cis retinal (made from retinol) and opsin

20
Q

xerophthalmia

A

dryness

21
Q

Bitot’s spots

A

foamy white spots of accumulated secretions

22
Q

keratomalacia

A

eye softens and becomes opaque

23
Q

The binding of retinoic acid to RXR and RAR promotes:

A

DNA transcription, which leads to cell differentiation and growth–>epithelial cells

24
Q

Consequences of too much retinol?

A

damage to bone and birth defects

25
Q

what is hyperkeratosis

A

obstruction and enlargement of hair follicles; this looks the same as vit. C deficiency

26
Q

This is the “final step” in vitamin A deficiency: the lens is covered so can’t see, ability for making tears is lost. This is irreversible

A

Corneal ulceration

27
Q

what is a static indicator of vitamin A status?

A

plasma retinol, showing whether liver stores are depleted

28
Q

VAD is responsible for ___ child deaths in places with Vit A deficiencies

A

1/4

29
Q

Examples of secondary deficiency?

A

fat malabsorption, protein deficiency, zinc deficiency, infectious diseases

30
Q

What is the EAR?

A

amount that meets needs of 1/2 population

31
Q

what is the EAR based on for fat soluble vitamins?

A

maintaining sufficient liver stores, using factorial methods

32
Q

EAR for women is ___ and ___ for men; only difference based on weight

A

500 mcg RAE; 625 mcg RAE

33
Q

what is the efficiency of storage of ingested vit A?

A

about 40%

34
Q

what is the minimum acceptable reserve of vit A?

A

20 mcg/g in liver

35
Q

how is RDA found from EAR?

A

standard deviation = 20%

36
Q

what is RDA for women? What about for men?

A

700 mcg RAE; 900 mcg RAE

37
Q

acute toxicity is called:

A

hypervitaminosis A

38
Q

what is the UL?

A

3000 mcg RAE (based on liver damage, alopecia, bone pain, teratogenic effect)

39
Q

NOAEL is:

A

No observable adverse effect lvl (studies w/ high intentional intakes)

40
Q

LOAEL is:

A

lowest observable adverse effect lvl–>look at case reports

41
Q

hepatotoxicity is found at the LOAEL of ___ mcg

A

14000

42
Q

if IU from retinol, divide by ____ to get mcg RAE

A

3.3333

43
Q

if IU from b-carotene in a supplement, divide by ____ to get mcg b-carotene, then divide by ___

A

3.33; 2

44
Q

supplemental b-carotene is harmful to ____

A

smokers (around 10 mg)

45
Q

what is lycopene found in?

A

makes red colour in tomatoes

46
Q

what is lutein found in?

A

yellow veg/fruit, green leafy veg

Nutr 221 (17 decks)

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