Free Radical Injury

Question 1

Free radicals are chemical species with an _______ in their (inner or outer?) orbit.

Answer 1

unpaired electron

Outer

Question 2

Free radicals form when chemical bonds are ____ and each fragment keeps ______ in the outer shell (in ____ reactions)

Answer 2

broken

one electron

redox

Question 3

Physiologic generation of free radicals occurs during ___________ where ___________ (complex ____) transfers electrons to _______.

This Partial reduction yields _______,_______ or _______

Answer 3

oxidative phosphorylation.

Cytochrome C oxidase

IV

oxygen
Superoxide (O-), Hydrogen peroxide (H202), andHydroxyl radicals (OH-).

Question 4

Pathologic generation of free radicals arises with

Ionizing ____
______
______

Drugs and chemicals

Answer 4

radiation

Inflammation
Transition Metals

Question 5

Pathologic generation of free radicals arises with

Ionizing radiation — _____ hydrolyzed to ______________

Answer 5

water

hydroxyl free radical

Question 6

Pathologic generation of free radicals arises with

Inflammation — ______ generates ______ radical ions (__) as well as _____ free radical (____) during _____ dependent killing by _______.

Answer 6

NADPH oxidase

superoxide free; O-

peroxynitrite; ONOO-

oxygen; neutrophils

Question 7

Pathologic generation of free radicals arises with

Transition Metals (e.g., _____ and iron) —Fe generates _____ radicals ( ____reaction).

Answer 7

Copper

hydroxyl free

Fenton

Question 8

Pathologic generation of free radicals arises with

Drugs and chemicals — ____ system of liver metabolizes drugs (e.g., acetaminophen), generating free radicals.

Answer 8

P450

Question 9

Free radicals cause cellular injury via _______ of ______ and ______ of ______ and proteins;

Answer 9

peroxidation of lipids

oxidation of DNA

Question 10

DNA damage is implicated in ______ and _______

Answer 10

ageing and oncogenesis.

Question 11

Elimination of tree radicals occurs via multiple mechanisms:

______

_______

______

Answer 11

Antioxidants

Enzymes

Metal carrier proteins

Question 12

Elimination of tree radicals occurs via multiple mechanisms:

Metal carrier proteins (e.g., ____ for ____ and _____ for ______ )

Answer 12

transferrin ; iron

ceruloplasmin; copper

Question 13

Elimination of tree radicals occurs via multiple mechanisms:

Antioxidants (e.g., ______ and _______)

Answer 13

glutathione

vitamins A , C, and E

Question 14

Elimination of tree radicals occurs via multiple mechanisms:

Enzymes

_________ (in _______)

___________ (in _______)

_________ (in _______)

Answer 14

Superoxide dismutase ; mitochondria

Glutathione peroxidase; mitochondria

Catalase; peroxisomes

Question 15

Elimination of tree radicals occurs via multiple mechanisms:

Enzymes
Superoxide dismutase

—converts _______ (__) to _____

Answer 15

Superoxide; O-

H202

Question 16

Elimination of tree radicals occurs via multiple mechanisms:

Enzymes

Glutathione peroxidase

—___+ free radical (__) —> ______ and _____

Answer 16

GSH; OH

GSSG and H20

Question 17

Elimination of tree radicals occurs via multiple mechanisms:

Enzymes

Catalase

converts ______ to ____ and _____

Answer 17

H2O2

O2 and H2O

Question 18

Other important causes of free radical injury

Carbon tetrachloride (CCl4)

Is Converted to ____, a free radical by ____ system of hepatocytes

Results in cell injury with swelling of ____; consequently, _____ , impairing ____ synthesis.

Can also lead to ___ change

Answer 18

CCl3-

CYP450

RER

ribosomes detach

protein

fatty

Question 19

Carbon tetrachloride (___) is an ______ used in the ______ industry

Answer 19

CCl4

Organic solvent

dry cleaning

Question 20

Decreased _________ production lead to fatty change in the liver

Answer 20

apolipoproteins

Question 21

Other important causes of free radical injury

Ischemia-Reperfusion injury

Return of ____ to ____ tissue results in production of ___-derived free radicals, which further damage tissue.

Leads to a continued rise in ___ enzymes (e.g., ____) after reperfusion of _____ myocardial tissue

Answer 21

blood; ischemic; O2

cardiac; troponin; infarcted

Question 22

Ischemia- Reperfusion Injury

However, under certain circumstances the restoration of blood flow to cells that have been ischemic (reversibly injured) but have not died (irreversibly injured), can paradoxically exacerbate and produce injury at an accelerated pace.

Answer 22

reversible; irreversible

Question 23

Decreased blood flow to a tissue or organ is called ______.

Answer 23

ischemia

Question 24

If the involved cells of the tissue are reversibly injured, the restoration of blood flow (reperfusion) is often ________.

Answer 24

beneficial

Question 25

Ischemia- Reperfusion Injury

However, under certain circumstances the restoration of blood flow to cells that have been ischemic (reversibly injured) but have not died (irreversibly injured), can ______________________________

Answer 25

paradoxically exacerbate and produce injury at an accelerated pace.

Question 26

Mechanism of reperfusion injury

New damage that may be initiated during reoxygenation includes:

Increased generation of _____

________

______ influx

Answer 26

reactive oxygen species

Inflammation

Ca2+ ion

Question 27

Free radicals in reperfusion injury are mainly produced by infiltrating ______.

Answer 27

leukocytes

Question 28

Oxygen dependent reaction- AKA________

Answer 28

Oxidative burst

Question 29

______ helps to form bleach with the help of _____ enzyme

Answer 29

Superoxide ion

Myloperoxidase

Question 30

The Fenton reaction

___ + ____ ——> ____+ ____+____

Answer 30

Fe2+; H202

Fe3+

OH-

OH*

Question 31

The _____ free radical gotten from the Fenton reaction leads to damage of _____ and other bio molecules and this repeated insult leads to _______

Answer 31

Hydroxyl

DNA

Carcinogenesis

Question 32

The most damaging free radical is ______???

Answer 32

Hydrogen peroxide