Pentose phosphate pathway & GAGs

Question 1

The pentose phosphate pathway involves the oxidation of Glucose-6-phosphate to this

Answer 1

Pentose-5-phosphate

Question 2

The pentose phosphate pathway involves the oxidation of this to pentose-5-phosphate

Answer 2

Glucose-6-phosphate

Question 3

Used in RBCs to determine thiamine status/deficiency

Answer 3

Transketolase assay

Question 4

Transketolase assay is used in RBCs to determine the status of this

Answer 4

Thiamine

Question 5

Is the NADPH:NADP+ ratio high or low in the cytoplasm?

Answer 5

High, favors reduction

Question 6

Is the NADH:NAD+ ratio high or low in the cytoplasm?

Answer 6

Low, favors oxidation

Question 7

3 main functions of the pentose phosphate pathway

Answer 7

Reduction of NADP+ to NADPH
Reduction of glutathione (for destruction of ROS)
Synthesis of ribose-5-phosphate

Question 8

Enzyme that provides protection against ROS

Answer 8

Glucose-6-phosphate dehydrogenase

Question 9

Oxidation product derived from unsaturated fatty acids used to test for ROS

Answer 9

Malondialdehyde

Question 10

Main cellular source of ROS in normoxia, hypoxia, and especially after oxygen reperfusion after a period of hypoxia

Answer 10

Mitochondria

Question 11

ROS formed by the mitochondria when ATP is high or low?

Answer 11

High ATP

Question 12

ROS formed by the mitochondria when membrane potential is high or low?

Answer 12

High membrane potential

Question 13

ROS formed by the mitochondria when electron transport is slow or fast?

Answer 13

Slow rate of electron transport

Question 14

Peroxisomal oxidation of very long chain fatty acids produces this

Answer 14

H2O2

Question 15

Hydroxyl radicals form in the presence of these:

Answer 15

Hydrogen peroxide and either superoxide or iron

Question 16

Iron in the presence of hydrogen peroxide may form this

Answer 16

Hydroxyl radicals

Question 17

When oxygen is reintroduced to tissue after a period of deprivation and results in lots of ROS formation and tissue damage

Answer 17

Reperfusion injury

Question 18

Protective enzyme that converts superoxides to hydrogen peroxide

Answer 18

Superoxide dismutase (SOD)

Question 19

Superoxide dismutase (SOD) converts superoxides to this

Answer 19

Hydrogen peroxide

Question 20

Loss of this gradient during anoxia is related to ROS formation on reperfusion

Answer 20

Loss of Ca2+ gradient

Question 21

Source of ROS that is regulated by Ca2+ and stimulates relaxation of smooth muscle, vasodilation of vessels

Answer 21

Endothelial nitric oxide synthase (eNOS)

Question 22

Source of ROS that provides a protective mechanism in macrophages and astroglia
Provides high levels of NO to kill bacteria

Answer 22

Inducible nitric oxide synthase (iNOS)

Question 23

Enzyme in phagocytic cells that produces superoxide, which is converted to H2O2

Answer 23

NADPH oxidase

Question 24

Enzyme in phagocytic cells that produces HOCl (bleach) to kill bacteria

Answer 24

Myeloperoxidase

Question 25

Enzyme in phagocytic cells that produces NO to kill bacteria and pathogens

Answer 25

Nitric oxide synthase II

Question 26

Condition that involves a lack of NADPH oxidase
Results in susceptibility to bacterial, fungal infections and abnormal inflammatory responses

Answer 26

Chronic granulomatous disease

Question 27

Some amytropic lateral sclerosis (Lou Gehrig’s disease) is caused by a genetic defect in this

Answer 27

Superoxide dismutase (SOD)

Question 28

Effect of a total lack of superoxide dismutase (SOD)

Answer 28

Fatal

Question 29

Peroxisomal enzyme that works with SOD to protect against ROS

Answer 29

Catalase

Question 30

Vitamin E, flavenoids, and ascorbic acid are examples of this

Answer 30

Antioxidants

Question 31

Non-enzymatic free radial terminators

Answer 31

Antioxidants

Question 32

Tripeptide of y-glutamyl-cysteinyl-glycine that protects against ROS

Answer 32

Glutathione

Question 33

Enzyme that reduces glutathione using NADPH from the pentose phosphate pathway

Answer 33

Glutathione reductase

Question 34

This enzyme is often deficient in people with origins in the malarial belt because it is protective against malaria

Answer 34

Glucose-6-phosphate dehydrogenase

Question 35

Deficiency of Glucose-6-phosphate dehydrogenase causes protection against malaria, but lowers levels of this

Answer 35

NADPH –> results in oxidative damage from H2O2

Question 36

Particles of damaged hemoglobin from ROS

Answer 36

Heinz bodies

Question 37

Glycosaminoglycan that is non-sulfated and serves as lubricant and shock absorbant

Answer 37

Hyaluronic acid

Question 38

Most abundant GAG in the body
Bind to collagen in cartilage and hold fibers in a tight, strong network

Answer 38

Chondroitin 4- and 6- sulfates

Question 39

Mucopolysaccharidosis that is very severe and is a alpha-L-iduronidase deficiency
Corneal clouding, mental retardation, dwarfing, coarse facial features
Degradation of dermatan sulfate and heparan sulfate are affected

Answer 39

Hurler syndrome

Question 40

Mucopolysaccharidosis that is an iduronate sulfatase deficiency
X-linked
Wide range of severity; no corneal clouding but physical deformity and mental retardation (mild to severe)
Degradation of dermatan sulfate and heparan sulfate are affected

Answer 40

Hunter syndrome

Question 41

Lysosomal storage disease that is severe and involves corneal clouding

Answer 41

Hurler syndrome

Question 42

Lysosomal storage disease that is X-linked and involves no corneal clouding

Answer 42

Hunter syndrome

Question 43

Deficiency of the ability to phosphorylate mannose
Skeletal abnormalities, restricted joint movement, coarse facial feature, severe psychomotor impairment

Answer 43

I-cell disease