Lecture 13 - Antioxidants Flashcards Preview

Food and Nutrition 1030 > Lecture 13 - Antioxidants > Flashcards

Flashcards in Lecture 13 - Antioxidants Deck (54)
Loading flashcards...
1

What is the role of antioxidants?

To protect cells from oxidative damage

2

What are the agents that protect from oxidative damage?

Vitamins quench the radicals

Minerals act as cofactors for enzymes

Phytochemcials

3

What is a free radical?

Something with an unpaired electron which damages lipids DNA RNA and proteins

4

What neutralizes free radicals?

Antioxidants

5

What is the definition of quench?

To get rid of, eliminate

6

What can antioxidants be thought of?

Dominos, a vitamin would sit inform of the domino to prevent the others from following

7

Why are minerals required for antioxidants?

They themselves aren't antioxidants, but they are just required for the function

8

What creates free radicals?

Any normal reaction in the body

Sun

9

What are the available forms of vitamin A?

Retinyl Esters: True vitamin a

Beta Carotene: Precursor for vitamin a (not true)

10

Where are Retinyl esters in the body?

Bonded to fat in the body. Esters will separate from fat to just have retynil

11

What is the storage form of Vitamin a

Retinal

12

What is retinol involved in?

Vision related

13

How do we end up with retinal?

Retinyl (from animal foods) > Converted to retinol > converted into retinal

Beta-carotene (from plants) > Converted to retinal

14

In the body, what are the different conversions of all the retinoids?

Retinol< >Retinal> Retanoic acid

15

What happens when we have too much retinal?

It can be converted back to retinol

16

What is the hormone version of vitamin a?

Retanoic Acid
-involved in DNA, transcription, Cell division, growth, reproduction

17

Do carotenoids all have the same antioxidant activity?

Yes, but not all of them are converted to vitamin a

18

What is the pathway for vitamin a once it has been ingested?

It is fat soluble and will end up in the chylomicrons then into the lymph and blood. Once in the blood it binds to binding proteins to be carried within the body

19

Where is vitamin a role in protein synthesis and cell differentiation

Takes place in epithelial cells on the skin and in the mucos membranes. Vitamin a is there to make sure those cells divide properly
-promotes differentiation of epithelial and goblet cells

20

How does vitamin a help with reproduction and growth?

Sperm development
Fetal development
Bone remodelling
Failure of growth in children

21

What does vitamin a deficiency look like?

Vitamin a status

22

What is vitamin a status?

Amount of vitamin a for you to use is dependant on how much is in your liver as well as your protein status

23

What happens to vitamin a when you don't have enough protein?

It won't transport vitamin a

24

What is vitamin a deficiency dependent on?

Vitamin a status and protein tatus

25

Where is vitamin a stored?

In the liver

26

What results from a vitamin a deficiency?

-Infectious disease
-Night blindness (lack of rhodopsin and inability to recover from changes in light)
-Xerophthalmia (total blindness due to drying and softening of cornea)
-Keratinization

27

How does vitamin a toxicity occur?

When binding proteins in the blood become swamped, the vitamin isn't excreted quickly so the free vitamin a can cause damage
-not seen with beta-carotene

28

Why isn't vitamin a a treatment for acne?

Vitamin a itself is not used as a treatment for acne but the retinoid used to treat acne have no vitamin a activity

29

What are some sources of beta carotene?

Yellow+Green veggies
-any vegetable really

Preformed vitamin a in any animal protein with some fat

30

What is RAE and what are the conversions??

Retinal activity equivalent

1microgram of preformed vitamin a= 1RAE

12micrograms of beta-carotene= 1RAE