PENTOSE PHOSPHATE PATHWAY AND NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE

Question 1

an alternative pathway to glycolysis for breaking down glucose

Answer 1

Pentose Phosphate Pathway (Hexose Monophosphate Shunt)

Question 2

a reducing agent that is essential for many cellular processes, such as the synthesis of fatty acids and cholesterol, and the detoxification of reactive oxygen species.

Answer 2

NADPH

Question 3

a precursor for the synthesis of nucleotides, which are the building blocks of DNA and RNA.

Answer 3

ribose 5-phosphate

Question 4

In this phase, glucose 6-phosphate is converted to ribose 5- phosphate and NADPH. Carbon 1 of glucose 6-phosphate is released as CO2.

Answer 4

Oxidative phase

Question 5

In this phase, ribose 5-phosphate can be converted back to glucose 6-phosphate, or it can be used to synthesize other five-carbon sugars

Answer 5

Non-oxidative phase:

Question 6

is required for the synthesis of fatty acids and cholesterol.

Answer 6

NADPH

Question 7

is a series of biochemical reactions that convert glucose 6-phosphate(G6P) to produce ribose 5-phosphate (R5P), NADPH, and other molecules.

Answer 7

PPP

Question 8

(irreversible; produces NADPH)

Answer 8

Oxidative phase

Question 9

(reversible)

Converts ribulose 5-phosphate (Ru5P) into ribose 5-phosphate (R5P).

Answer 9

Non-oxidative phase

Question 10

first step in the pentose phosphate pathway, and it produces NADPH

Answer 10

Dehydrogenation of glucose 6-phosphate

Question 11

an enzyme that catalyzes the oxidation of glucose 6-phosphate to 6- phosphogluconolactone.

Answer 11

Glucose 6-phosphate dehydrogenase (G6PD)

Question 12

is a competitive inhibitor of G6PD.

Answer 12

NADPH

Question 13

When the NADPH/NADP+ ratio is high, G6PD activity is ______

Answer 13

inhibited

Question 14

When the NADPH/NADP+ ratio is low, G6PD activity is _______

Answer 14

increased.

Question 15

If insulin is increased, it upregulates the expression of G6PD ____ the amount of G6PD protein that is produced in the cell.

Answer 15

increases

Question 16

second step in the oxidative phase of the pentose phosphate pathway, and it produces NADPH.

Answer 16

Formation of ribulose 5-phosphate

Question 17

6-Phosphogluconolactone is hydrolyzed by

Answer 17

6-phosphogluconolactone hydrolase.

Question 18

Oxidation of 6-phosphogluconate to ribulose 5-phosphate is catalyzed by

Answer 18

6-phosphogluconate dehydrogenase.

Question 19

allow the cell to convert ribulose 5-phosphate (produced by the oxidative phase of the pathway) to either ribose 5-phosphate (needed for nucleotide synthesis) or to intermediates of glycolysis (fructose 6-phosphate and glyceraldehyde 3- phosphate)

Answer 19

REVERSIBLE NON- OXIDATIVE REACTIONS

Question 20

If the cell needs more NADPH than ribose 5-phosphate:

Answer 20

the transketolase and transaldolase enzymes will convert ribulose 5-phosphate to glyceraldehyde 3-phosphate and fructose 6-phosphate, which can then be fed into glycolysis to produce NADPH.

Question 21

If the cell needs more ribose 5-phosphate than NADPH:

Answer 21

then the transketolase and transaldolase enzymes will convert glyceraldehyde 3-phosphate and fructose 6-phosphate to ribose 5-phosphate

Question 22

is a coenzyme that is similar to NADH, but it has an additional phosphate group.

Answer 22

NADPH

Question 23

Some examples of reductive biosynthetic reactions that use NADPH include:

Answer 23

Fatty acid synthesis
Cholesterol synthesis
Nucleotide synthesis
Amino acid synthesis

Question 24

is the process of building molecules by adding hydrogen atoms.

Answer 24

REDUCTIVE BIOSYNTHESIS

Question 25

is a reactive oxygen species (ROS) that can damage cells.

Answer 25

Hydrogen peroxide (H2O2)

Question 26

NADPH is used by the enzyme ______ to reduce H2O2 to water.

Answer 26

glutathione peroxidase

Question 27

is found in all cells in the body, and it is especially important in cells that are exposed to high levels of ROS, such as liver cells.

Answer 27

Glutathione peroxidase

Question 28

A condition in which there is an imbalance between ROS production and ROS detoxification. contribute to a variety of diseases, including cancer, heart disease, and Alzheimer's disease

Answer 28

Oxidative stress

Question 29

Uses NADPH to reduce hydrogen peroxide (H2O2) to water. This protects cells from the damaging effects of H2O2.

Answer 29

Glutathione peroxidase

Question 30

Regenerates reduced glutathione, which is used by glutathione peroxidase to reduce H2O2. NADPH is also used in this reaction.

Answer 30

Glutathione reductase

Question 31

Converts superoxide to H2O2. Superoxide can damage cells even more than H2O2.

Answer 31

Superoxide dismutase

Question 32

Converts H2O2 to water and oxygen.

Answer 32

Catalase

Question 33

Antioxidant chemicals

Answer 33

Ascorbate (vitamin C) Vitamin E β-carotene

Question 34

Reduces ROS, including H2O2 and superoxide.

Answer 34

Ascorbate (vitamin C) Vitamin E β-carotene

Question 35

is a process by which white blood cells (such as neutrophils) engulf and kill bacteria and other foreign particles. This is an important part of the immune system's defense against infection.

Answer 35

Phagocytosis

Question 36

These mechanisms use pH changes in phagolysosomes and lysosomal enzymes to destroy pathogens.

Answer 36

Oxygen-independent mechanisms

Question 37

These mechanisms use the enzymes NADPH oxidase and myeloperoxidase (MPO) to generate reactive oxygen species (ROS), which kill bacteria

Answer 37

Oxygen-dependent mechanisms

Question 38

rare genetic disorder caused by a deficiency in NADPH oxidase. People with CGD are more susceptible to severe, persistent infections.

Answer 38

Chronic granulomatous disease (CGD)

Question 39

Highly reactive molecules that can damage cells. produced as byproducts of normal metabolism, but they can also be produced in response to stress or exposure to toxins.

Answer 39

Reactive oxygen species (ROS)

Question 40

A vesicle formed by the fusion of a phagosome and a lysosome.

Answer 40

Phagolysosome

Question 41

contain bacteria or other foreign particles that have been engulfed by the cell.

Answer 41

Phagosomes

Question 42

contain enzymes that can break down bacteria and other foreign particles.

Answer 42

Lysosomes

Question 43

is a gas produced by many cells in the body, including the lining of blood vessels, nerve cells, and immune cells.

Answer 43

Nitric oxide (NO)

Question 44

NO causes blood vessels to relax and widen, which _____blood flow to tissues.

Answer 44

increases

Question 45

has a very short half-life in the body, meaning that it breaks down quickly. This is because it is a free radical, which means that it has an unpaired electron

Answer 45

NO

Question 46

is an enzyme that produces nitric oxide (NO).

Answer 46

Nitric oxide synthase (NOS)

Question 47

3 types of NOS:

Answer 47

Endothelial NOS (eNOS) Neuronal NOS (nNOS) Inducible NOS (iNOS)

Question 48

is found in the lining of blood vessels and produces NO to keep blood vessels open and relaxed.

Answer 48

Endothelial NOS (eNOS)

Question 49

is found in nerve cells and produces NO to regulate nerve signaling.

Answer 49

Neuronal NOS (nNOS):

Question 50

is found in many cells, including macrophages and neutrophils, and is produced in response to infection or inflammation

Answer 50

Inducible NOS (iNOS)

Question 51

NO causes blood vessels to relax and widen, which increases blood flow. It does this by activating an enzyme called guanylate cyclase, which produces

Answer 51

cyclic guanosine monophosphate (cGMP).

Question 52

is a signaling molecule that causes smooth muscle cells in the blood vessel walls to relax.

Answer 52

cGMP cyclic guanosine monophosphate

Question 53

are immune cells that help to fight infection. iNOS produces NO in macrophages, which can kill bacteria and other pathogens.

Answer 53

Macrophages

Question 54

- is a X-linked genetic disorder characterized by hemolytic anemia caused by the inability to detoxify oxidizing agents.

Answer 54

G6PD deficiency

Question 55

is a condition in which the body's red blood cells are destroyed faster than they can be replaced

Answer 55

Hemolytic anemia

Question 56

If G6PD activity is ___ , red blood cells are more likely to be damaged by free radicals.

Answer 56

reduced

Question 57

NADPH is used to reduce:

Answer 57

glutathione (GSH)

Question 58

an antioxidant that helps to neutralize free radicals

Answer 58

glutathione (GSH)

Question 59

Commonly used drugs that produce hemolytic anemia in patients with G6PD deficiency: “AAA”

Answer 59

antibiotics (for example, sulfamethoxazole and chloramphenicol), antimalarials (for example, primaquine), and antipyretics (for example, acetanilid).

Question 60

the hemolytic effect of ingesting fava beans, is not observed in all individuals with G6PD deficiency

Answer 60

Favism

Question 61

is the most common precipitating factor of hemolysis in G6PD deficiency

Answer 61

Infection