Vitamin E 2.0

Question 1

LOO*

Answer 1

Lipid peroxyl radical

Question 2

LOOH

Answer 2

Lipid hydrogen peroxide

Stablized PUFA; however, it has been modified so the function of this lipid is going to be different.

Question 3

L*

Answer 3

Lipid radical

Question 4

HOO*

Answer 4

Hydroperoxyl radical

Question 5

O2*

Answer 5

Superoxide radical

Question 6

OH*

Answer 6

Hydroxyl radical

Question 7

H2O2

Answer 7

Hydrogen peroxide

Question 8

Explain:

LH + OH* ———> L* + H2O

Answer 8

Free hydroxyl radical steals an electron from PUFA

Resulting in a lipid radical and water

Question 9

Explain:

LH + O2 ——> L* + HO*2

Answer 9

A PUFA can also spontaneously react with molecular oxygen

Resulting in a lipid radical and a hydroperoxyl radical

This reaction results in two radicals

Question 10

If L* reacts with O2, what does it form?

Answer 10

LOO* (lipid peroxyl radical—HIGHLY reactive)

Question 11

Once LOO* is formed, what will happen next?

Answer 11

LOO* + LH ——> L* + LOOH

The lipid peroxyl radical will react with a PUFA

Resulting in a lipid radical and LOOH (lipid hydrogen peroxide)

this is a self-propagating reaction

Question 12

Endogenous antioxidants

Answer 12

Glutathione
Superoxide dismutase

Question 13

Exogenous antioxidants

Answer 13

Vitamin C and vitamin E

Question 14

What are 2 radicals that vitamin E can react with?

Answer 14

HOO* (hydroperoxyl radical)
L*

Question 15

What is the principal function of vitamin E?

Answer 15

Maintenance of cell membrane integrity by preventing the oxidation of PUFAs in phospholipids of the cellular membranes by free radicals

Question 16

What tissues are at the highest risk to oxidation?

Answer 16

Lung
Brain
RBCs