Reactive Oxygen Species

Question 1

Hypoxia inducing factor (HIF) is a_________in response to hypoxia

Answer 1

Transcriptional regulator

Question 2

HIF under normal conditions is recognized by the enzyme________which hydroxylate it which are then recognized by_______that ubiquinates it for degradation

Answer 2

PHD (Prolyl hydroxylase);VHL

Question 3

Under hypoxia conditions, HIF -1 alpha and HIF-1 beta bind to________on the DNA as a transcription factor to drive the expression of genes for_______

Answer 3

HRE (Hypoxia response element); glycolysis, increase RBC’s

Question 4

Mitochondrial diseases derive from the________of the ETC

Answer 4

Overuse

Question 5

Overuse of the electron transport chain causes a leakage of________which increases the likelihood of producing ROS

Answer 5

Electrons

Question 6

Oxidative phosphorylation disorders can derive from____________which are responsible for building the ETC

Answer 6

mutations in mitochondrial genome

Question 7

ROS’s have what kind of effect on mitochondria

Answer 7

Decrease ATP and electrochemical potential

Lactic acid build up

Question 8

Mitochondrial disorder effect what kinds of cells

Answer 8

Cells which require high ATP

Question 9

Name the common free radicals

Answer 9

Superoxide
Hydroxyl radical

Question 10

Superoxide formed by

Answer 10

adding 1 electron to O2

Question 11

Hydrogen peroxide is formed by

Answer 11

Adding 1 electron and 2 protons to superoxide

Question 12

An unavoidable byproduct of the ETC is

Answer 12

Superoxide

Question 13

_________is a major site of ROS production

Answer 13

Mitochondria

Question 14

Reacting hydrogen peroxide with an H ion and an electron forms the radical

Answer 14

Hydroxyl

Question 15

Superoxide is mainly generated in which sites of the ETC

Answer 15

Complex 1 and 3

Question 16

Peroxisomes are a sight for which ROS during fatty acid oxidation? How are they formed?

Answer 16

Hydrogen peroxide; transfer of electrons from FADH2 to O2

Question 17

This family of enzymes catalyzes the transfer of electrons from NADPH to O2 to form superoxide

Answer 17

NADPH oxidase

Question 18

NADPH oxidases are found in________ and produce ROS to kill engulfed microbes within the cell

Answer 18

Membranes of phagolysosomes in immune cells

Question 19

The enzyme_______catalyzes the formation of________from_______which then attacks bacteria

Answer 19

Myeloperoxidase; HOCL (Hypochlorus acid); hydrogen peroxide and Cl

Question 20

ROS can effect DNA by

Answer 20

Alterating nucleotide bases
Break the depxyribose backbone
Programmed cell death if DNA cannot be prepared

Question 21

ROS can effect Lipids by

Answer 21

Lipid peroxidation which changes membrane viscosity,

increasing membrane permeability for calcium

Increasing membrane permeability to increase swelling

Question 22

ROS can effect proteins by

Answer 22

Amino acid conversions
Cleavage of peptide bonds

Question 23

This enzyme is the primary defence against ROS which converts superoxide to hydrogen peroxide and O2

Answer 23

Superoxide dismutase

Question 24

The gene encodes for superoxide dismutase

Answer 24

SOD1

Question 25

Superoxide dismutase is found in

Answer 25

Mitochondria, cytosol, and extracellularly

Question 26

This enzyme promotes the reaction of converting H2O2 to water and O2

Answer 26

Catalase

Question 27

Catalases are found in_______and are high yield in the kidney and liver

Answer 27

Peroxisomes

Question 28

Catalases protect the cell from

Answer 28

Respiratory burst

Question 29

This enzyme exists as a family of selenium enzymes and are the means for converting H2O2 outside of peroxisomes

Answer 29

Glutathione

Question 30

__________is essential for protection against free radical injury and is provided by the penthouse phosphate pathway

Answer 30

NADPH

Question 31

GSH is oxidized to form GSSG which turns H2O2 into H2O using________as the enzyme

Answer 31

Glutathione peroxidase

Question 32

This enzyme in the pentode phosphate pathway maintains a high NADPH ratio and is the rate limiting step for the pentode phosphate pathway

Answer 32

G6PDH (glucose-6-phosphate-dehydrogenase)

Question 33

G6PDH is inhibited by_____ and activated by_____

Answer 33

NADPH; NADP

Question 34

Nrf2 is a______which activates the antioxidant response element

Answer 34

Transcription factor

Question 35

Antioxidant response element (ARE) dependent enzymes include

Answer 35

Catalase and superoxide dismutase

Question 36

Nrf2 is bound to an inactive form when bound to________which directs ubiquitination of Nrf2 under normal conditions

Answer 36

Keap1

Question 37

Nrf2 is activated under________by dissociation of Keap1

Answer 37

Oxidative stress