Micronutrients as Antioxidants

Question 1

Define Antioxidant

Answer 1

Agent that functions to stop oxidative stress

Question 2

Radical Scavenging

Answer 2

accept or donate electrons to terminate chain reactions

Question 3

Radical pro-oxidants

Answer 3

superoxide, Hydroxyl radical, nitric oxide, peroxyl radical

Question 4

Non-radical oxidants

Answer 4

hydrogen peroxide, ozone, disulfide, hypochlorous acid

Question 5

What are the antioxidants

Answer 5

Selenium, C, E, A, Beta-carotene, Lutein, Lycopene, Flavonoids, Glutathione, Superoxide dismutase, Glutathione peroxidase, Catalase, Thioredoxin reductase

Question 6

Vitamin C Overview

Answer 6

ascorbate, ascorbic acid, water-soluble, ascorbic acid is an electron donor

Question 7

Good sources of Vitamin C:

Answer 7

strawberries, oranges, kiwis, red pepper, broccoli, tomatoes

Question 8

What is the UI of Vit C?

Answer 8

2 g/d (bloating, diarrhea)

Question 9

Who might benefit from a vit c supplement?

Answer 9

endurance athletes

Question 10

How is vitamin C absorbed and stored?

Answer 10

In small intestine through sodium-dependent vitamin c transporters, 80% of what is ingested is absorbed, acorbate is primary circulating form, water soluble

Question 11

Vitamin C functions

Answer 11

Cofactor for oxygenase reactions: 
-neurotransmitter synthesis
-carinitine synthesis
-collagen synthesis
Antioxidant electron donor
-Increases absorption of non-heme iron absorption
-prevention of protein oxidation
-prevention of ldl oxidation
-quenching of ros
-quenching of lipid peroxidation

Question 12

Vitamin C deficiency

Answer 12

Scurvy!
Symptoms: petechial hemorrhage, bleeding gums, ecchymoses, hyperkeratosis, joint pain, shortness of breath
At risk: cancer cachexia, poor intake, malabsorption, alcoholism

Question 13

Vitamin E overview

Answer 13

group of fat-soluble compounds, alpha-tocopherol is the only form recognized to meet human requirements

Question 14

Sources of Vit E

Answer 14

nuts, oils, mango, pumpkin, sweet potato,

Question 15

RDA and UI of Vit E

Answer 15

RDA for Adult, 15mg, UL: 1,000 mg/d based on risk of hemorrhage (increases blood coagulation time)

Question 16

Vitamin E absorption

Answer 16

taken into enterocyte, incorporated into chylomicrons->lymph-> blood about half of vit E consumed is absorbed

Question 17

Functions of Vitamin E

Answer 17

Free radical scavenging antioxidant
cell signaling
regulation of gene expression
protection of endothelial integrity

Question 18

Vitamin E deficiency and toxicity

Answer 18

rate, there is no storage organ for Vit E

Question 19

Carotinoids overview

Answer 19

family of 600 fat- soluble plant pigments

alpha carotene, beta carotene, beta cryptoxanthin, lutein, zeaxantin, lycopene

Question 20

carotenoids functions

Answer 20

antioxidant activity, light filtering, cellular communication, provitamin A activity

Question 21

flavenoids overview

Answer 21

anthocyandidins, flavanols, flavanones, flavonols, flavones, isoflavones,

Question 22

flavonoid functions

Answer 22

antioxidant activity, cell-signaling effects

Question 23

Define oxidative stress

Answer 23

an imbalance in pro-oxidant and antioxidant reactions that causes macromolecular damage or disrupts biologic redox signaling