Stiner - Oxygen and Life

Question 1

The most prevalent ROS in the blood and tissue is ___________

Answer 1

hydrogen peroxide

Question 2

The _____ radical of ROS is the most reactive and damaging

Answer 2

OH

Question 3

ROS include ______ anion (first product) , ________ ion, and ________ radical

Answer 3

superoxide anion
hypochlorite ion
hydroperoxyl radical

Question 4

True or False

All ROS are bad

Answer 4

False, ROS are required for the thyroid gland to produce thyroxine and immune cells produce ROS to kill pathogens via pagocytosis

Question 5

ROS are formed by three major mechanisms in vivo:

1. via reaction of ______ with decompartmentalized ____ ____
2. As a side reaction of __________ _____ transport
3. Normal ______ reaction

Answer 5

oxygen
metal ions

mitochondrial electron

enzymatic

Question 6

One of the most sensitive site of ROS damage is the ____ ______; because it is rich with _____ ______ _____ which react readily with ROS; this can cause the cell to undergo ______

Answer 6

cell membrane
polyunsaturated fatty acids
apoptosis

Question 7

Cells have a variety of _______ defenses against the harmful effects of ROS

Answer 7

enzymatic

Question 8

________ ________ converts 2 superoxide anions into a molecule of hydrogen peroxide and one of oxygen and ________ coverts hydrogen peroxide to water

Answer 8

superoxide dismutase

catalase

Question 9

Some small molecules are antioxidants including vitamins ____, _____, ____, as well as ____ ____

Answer 9

A
C
E
uric acid

Question 10

Vitamin ____ reacts with organic radical, neutralizing it, converting to dehydroascorbate and dehydroascorbate reductase converts that back to vitamin _____

Answer 10

C

Question 11

Oxygen (O2) is usually ______, high heat causes it to become _______, with body temperature O2 is always activated by _______ _____

Answer 11

inert
reactive/activated
metal ions

Question 12

ROS are _______ ______, reactive forms of oxygen

Answer 12

partially reduced

Question 13

______ is the most unstable ROS

Answer 13

superoxide

Question 14

The hydroxyl radical reacts with _____, damaging the _______ _____ and the ______ ______

Answer 14

DNA
nucleotide bases
deoxyribose backbone

Question 15

True or False

ROS play a role in diseases involving inflammation (arthritis), infection, cancer-mutagenesis, and aging

Answer 15

True

Question 16

________ antioxidants are antioxidants we get from out diet by eating antioxidant rich foods and/or taking supplements; although it is nearly impossible to get enough antioxidants to neutralize all ROS generated

Answer 16

exogenous

Question 17

_________ antioxidants are made by our bodies; are the more potent of the 2 and can repair all of the free radical damage by initiating cell regeneration; includes GSH, ALA, SOD and catalase, Q10,

Answer 17

endogenous