Antioxidants

Question 1

what are examples of stressors?

Answer 1

aging, wounding, xenobiotics, radiation/light, heat and cold, heavy metals, pollutants, hormones

Question 2

notable RNS?

Answer 2

nitric oxide, nitrogen dioxide

Question 3

places where free radicals are made?

Answer 3

mitochondria; vacuoles; nucleus, lysosomes, peroxisomes, ER, cyto, membrane

Question 4

what is singlet oxygen involved in?

Answer 4

skin, photodamage

Question 5

what cause production of free radicals?

Answer 5

smoking, strenuous exercise

Question 6

how is superoxide radical created?

Answer 6

O2 react with catecholamines, semiquinone intermediate in mito, NADPH oxidase in membrane, drug/toxin metabolism (WBCs)

Question 7

H2O2 is produced by ____

Answer 7

SODs (superoxide dismutases); rxn ascorbate with O2

Question 8

H2O2 is produced in:

Answer 8

peroxisomes, activated neutrophils, ischemia-reperfusion

Question 9

this radical is a “severe threat to living systems”, form when exposed to gamma rays and in Haber-Weiss and Fenton rxns

Answer 9

hydroxyl radical

Question 10

a peripheral e- excited to a higher state, and mroe rxtive than ground state Oxygen

Answer 10

singlet molecular oxygen

Question 11

how is singlet oxygen formed?

Answer 11

via photochemical rxn, enzymatic rxns (resp bursts), peroxidations

Question 12

in lipid peroxidation, O2 is slow oxidant in ___ phase, fast oxidant in ___ phase

Answer 12

initiation; propagation

Question 13

proteins most reactive?

Answer 13

proline, histidine, argenine, cysteine

Question 14

lipid peroxidation releases rxtive ___

Answer 14

aldehydes

Question 15

diseases involving oxidative stress

Answer 15

inflammation (arthritis, alzheimer’s, MS, infection), cancer, atherosclerosis, ischemia-reperfusion, aging

Question 16

ischemia is caused by:

Answer 16

cessation of blood/oxygen supply

Question 17

3 ways to defend against prooxidants:

Answer 17

prevent formation, intercept, repair damage

Question 18

interception can be by ___ antioxidants and ____ enzymes

Answer 18

classical; phase 2

Question 19

phase 2 enzymes catalytically remove proox and ___ for excretion

Answer 19

conjugate

Question 20

classical antiox prevent urther damaging activity, called “____” antioxidant

Answer 20

chain-breaking

Question 21

examples of small watersoluble antiox

Answer 21

glutathione, uric acid, vit. c

Question 22

ex. of small lipid soluble antiox

Answer 22

vit. E, betacarotene, coenzyme Q

Question 23

protein antiox intracellular examples

Answer 23

SOD 1+2,glutathione peroxidase, catalase, ferritin

Question 24

protein antiox cell mem examples

Answer 24

phopholipid hydroperoxide

Question 25

protein antiox extracell ex

Answer 25

SOD 3, ecGPx, plasma proteins (albumin)

Question 26

essential diet antiox

Answer 26

vit E and C, minerals, sulfur amino acids (glutathione)

Question 27

nonessential diet antiox

Answer 27

carotenoids, lipoic acid, uric acid, coenzyme Q, flavonoids, polyphenols, phytochemicals

Question 28

GPx (glutathione peroxidase) contains __ Se

Answer 28

4

Question 29

AH2 + H2O2 --> ?

Answer 29

DHA + 2 H2O

Question 30

2 GSH + H2O2 --> ?

Answer 30

GSSG + 2 H2O

Question 31

catalase largely present in ____

Answer 31

peroxisomes, WBC/RBC

Question 32

catalase turns 2 H2O2 into ___ + ___

Answer 32

2 H2O; O2

Question 33

scavengers of OH radical?

Answer 33

vit C, uric acid, DHLA, GSH, SH proteins

Question 34

AH2 + OH* --> ?

Answer 34

H2O + AH*

Question 35

AH2 + 1O2 --> ?

Answer 35

AH* + O2* + H

Question 36

carotenoid + 1O2 --> ?

Answer 36

carotenoid* +O2

Question 37

carotenoid* --> ?

Answer 37

carotenoid + heat

Question 38

1O2 is ___ by carotenoids

Answer 38

quenched

Question 39

vit E regen by:

Answer 39

ubiQH2, vit C

Question 40

ubiQH2 regen by:

Answer 40

mito reductases (NADH or succinate)

Question 41

vit C regen by:

Answer 41

dismutation, GSH, DHLA

Question 42

the reaction: 2 AH* -->AH2 + DHA is referred to as ____

Answer 42

dismutation