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Flashcards in Free Radicals and Antioxidants Deck (38):
1

propertoes of oxygen in ground state

can absorb energy from light, porphyrins or other sources and get to the exicted state

2

how is superoxide anion generated

one electron reduction of molecular oxygen, usually invovling a metalb catalyst

3

how is hydrogen peroxide generated

transfer of 2 electrons

4

how is hydroxyl radical generates

transfer of 3 electrons.

5

which of the oxygen radicals is the most reactive

hydroxyl radical

6

how do you get reactive oxygen from ETC

quinone in complex III gets oxidized to form superoxide anion

7

how do you get reactice oxyen from NADPH/cytochrome oxidases

if second transfer of electrons fails, superoxide anion is released from enzyme

8

chronic alcohol consumption stresses the liver in what 2 ways

oxidative stress from hydrogen peroxide
DNA damage

9

what reactive oxygen does the xanthine oxidase reaction produce

hydrogen peroxide

10

how are iron and copper involved in free radicals

free iron and copper irons can donate an electron to molecular oxygen or hydrogen peroxide

11

what is iron boudn to

ferritin and transferrin

12

what is copper bound to

ceruloplasmin

13

what causes hereditary hemochromatosis

mutation in HFE gene

14

symptoms of hereditary hemochromtosis

destruction of liver, pancreaus, and heart muscle cells

15

where is superoxide dismutase (SOD) exxpressed

cytoplasm and mitochondria

16

SOD function

convert superoxided into hydroen perodxide

17

catalase

heme containing enzyme that detoxes hydrogen perdoixe

18

glutathione peroxidase

uses electrons to reudce hydrogen peroxide

19

ascorbic acid

water soluble electron donor to free radicals

20

vitamine E

lipi solube radical scapventure

21

waht does vit E protect against

damage from free radicals as well as from lipid peroxidation

22

how does vit A reduce oxidative damage to membranes

electron donor for reduction of radicals
quenches vibration energy of singlet oxygen

23

GSH

has thiol group that can donate elctron to radical, becomes oxidized

24

how is GSSG reduceed back to GSH

glutathione reductase

25

polyphenols

water soluble antioxidants that are in plant extracts

26

where do most electrons originate from

NADPH

27

how does glutathione peroxidase help fight radical damage in RHCs

destroy hydrogen and organic peroxides

28

how does SOD help fight radical damage in RBCS

destroy superoxide

29

how does catalase right radical damage in RBCs

convert hydrogen peroxide

30

what in RBCs directly reacts with ROS

RSH, vit C, vit E

31

how does methemoglobin help fight radical damage in RBCs

methemoglobin reductase reparis oxidative damage by reducing iron, convert methemoglboin back to hemoglobin

32

when is oxidative stress present

when conc of ROS exceeds cell capcity for detox

33

what is oxidative stress daaming to

lipids, DNA, proteins

34

the most serious damage by hydroxyl radical to membrans is what

peroxidation of polyunsaturated fatty acids

35

process of lipid peroxidation

1) hydroxyl radical takes electron from PUFA, produces lipid radical
2) lipid radical react with oxygen to form lipid peroxides
3) liipd peroixes are unstable and take elctrons

36

what is a good marker for oxidative stress

plasma malondialedhyde conc

37

how does hydroxyl radical fuck up DNA

produces DNA double stranded breaks

38

what forms peroxynitirite

superoxide and peroxynitrate anions