HMP Shunt Pathway

Question 1

What is the overall point of the HMP Shunt Pathway?

Answer 1

Alternate Pathway for Glucose Metabolism

Question 2

Roles of HMP Shunt Pathway

Answer 2

Question 3

What Pathway will require 5 carbon Sugars

glycolysis?

glycogen storage

fatty acid synthesis

RNA synthesis

TCA Cycle

Answer 3

RNA synthesis — we can make the 5 carbon sugars needed for RNA (and DNA?)

Question 4

Oxidative vs. Non-Oxidative Pathways

Answer 4

Question 5

Transketolase vs. Transaldolase

Answer 5

Question 6

Transaldolase requires

Answer 6

a lysine in the active site.

Question 7

Which other enzyme requires thiamin as a cofactor?

Pyruvate kinase

Pyruvate dehydrogenase

Isocitrate dehydrogenase

Aldolase

Aminoacylt tRNA

Alpha KG Dehydrogenase

Answer 7

Pyruvate dehydrogenase

Alpha KG Dehydrogenase

Question 8

Review of Thiamine Deficiency

Answer 8

Question 9

The Oxidative Steps of HMP

Answer 9

Question 10

Epimerization and Isomerization of Ru5P

Answer 10

Question 11

What other reaction pathway contains a similar Epimerization reaction?

Glycolysis

Fructose Metabolism

Galactose Metabolism

TCA Cycle

Mitochondrial Shunts

Answer 11

Galactose Metabolism — C4 Epimerase

TCA Cycle — Isomerase but not epimerization

Question 12

First Transketolase Reaction

Answer 12

Question 13

First TransALDOLASE Reaction

Answer 13

Question 14

What happens to the E4P produced?

Answer 14

Question 15

Regulation of the HMP Shunt Pathway

Answer 15

Question 16

Which pathway requires NADPH?

Glycolysis

Gluconeogenesis

Xenobiotic Detoxification

Fatty Acid oxidation

TCA Cycle

Ox. Phos.

Answer 16

Xenobiotic Detoxification — Cytochrome System requires NADPH

Question 17

What are the 3 types of Cells?

Answer 17

1. Cells require more R5P than NADPH
2. Cells that need equal amounts of R5P than NADPH
3. Cells require NADPH but not R5P

Question 18

Cells that require more R5P than NADPH

Answer 18

Question 19

Cells that Need Equal Amounts of NADPH and R5P

Answer 19

Question 20

Cells that Require NADPH, but not R5P

Answer 20

Question 21

Rationale behind the different Pathways

Answer 21

Question 22

Cells that need NADPH and Carbons for Biosynthesis

Answer 22

Question 23

Overview of the Metabolism

Answer 23

Question 24

Summary of Directions of the HMP Pathway

Answer 24

Question 25

Biochemical Consequences of G6PDH Deficiency

Answer 25

Question 26

Symptoms of People with G6PDH Deficiency

Answer 26

Soldiers got the following symptoms: Scleral Icterus Jaundice Hemolytic Anemia Mediterranean descent Mutation on X-Chromosome that was G6P They were aysomptomatic until they received drugs at home. Drugs are oxidizing agents which triggered the disorder. RBC’s are primarily affected. Remember RBC’s have no mitochondria. THE RBC use transhydrogenase as their only means of generating NADPH

Question 27

Consequences of G6PDH Deficiency Continued

Answer 27

Question 28

Glutathione Pathway

Answer 28

Question 29

G6PDH Deficiency Defined

Answer 29

Question 30

G6PDH Resistance to Malaria

Answer 30

Question 31

Sickle Cell Carrier Resistance to Malaria

Answer 31

Question 32

Overview of Eythrocyte Metabolism

Answer 32

Erythrocyte has pathways that some other cells don’t. Upper Right Branch of the pathway is dependent on NADP concentration. Iron atom in center of heme binds oxygen but it can only bind…... not the ferric state. Methemoglobin gets converted back to the hemoglobin by met reductase. Whenever we go through the 2,3 BPG shunt we’re by passing the generation of an ATP.

Question 33

Reactive Oxygen Species

Answer 33

Question 34

Which organelle would you expect to exhibit the most damage from ROS? ## Footnote Lysosome Mitochondria Golgi Apparatus Endoplasmic reticulum Nucleus

Answer 34

Mitochondria

Question 35

Enzymes which use Molecular Oxygen

Answer 35

Question 36

Cytochrome P450 Family

Answer 36

Question 37

More on Cytochrome P450

Answer 37

Question 38

Tylenol Toxicity

Answer 38

Question 39

Radical Damage and Chain Terminators

Answer 39

Question 40

Anti-Oxidant Enzymes

Answer 40

Question 41

A major role of the HMP shunt pathway is? Generate ATP Generate NADH Generate FADH Bypass PFK1 Provide cofactor for anabolic pathways Providing cofactor for catabolic pathways

Answer 41

Provide cofactor for anabolic pathways

Question 42

Production of glucose from ribose 5-phsophate in the liver would require which one of the following enzymes? Pyruvate carboxylase pyruvate dehydrogenase PEP Carboxykinase G3P DH Fructose 1,6 Bisphosphatatse

Answer 42

Fructose 1,6 Bisphosphatatse

Question 43

Level of oxidative damage is 10 times greater than nuclear DNA Why? Superoxide dismutase is present in the mitochondria Nucleus lacks glutathione Nuclear membrane presents a barrier to ROS Mitochondrial membrane is permeable to ROS Mitochondria DNA Lacks Histones

Answer 43

Mitochondria DNA Lacks Histones — So it’s not protected from ROS

Question 44

Answer 44

G6PDH Deficiency?

Question 45

Chronic Alcoholic has nystagmus, inability to balance, easily confused. Which enzyme assay would likely demonstrate a reduction of activity?

Answer 45

Alphaketoglutarate dehydrogenase — only enzyme listed that requires Thamine

Question 46

See Above. Assay of which of the following enzymes can determine a biochemical reason for these symptoms? ## Footnote Isocitrate DH Transaldolase Transketolase G3PDH G6pDH

Answer 46

Transketolase

Question 47

New born gets treated with thiamin to alleviate symptoms of lactic acidosis lethargy and poor muscle tone. Why is the treatment successful? Such treatment allows the mutated enzyme to produce NADPH The mutated enzyme has a reduced Km for thiamine The mutated enzyme has an increased Km for thiamine Such treatment allows cells to produce 5 carbon sugars which are necessary for cell division

Answer 47

The mutated enzyme has an increased Km for thiamine (I.e. Reduced Affinity)

Question 48

The conversion of Ribose 5 Phosphate to free glucose in liver requires? G6PDH Pyruvate Kinase Malate Dehydrogenase Aldolase G3PDH

Answer 48

Aldolase

Question 49

American american male had fave beans he was fatigued and shows anemia. What is the likely defect? ## Footnote NADH NAD Reduced Glutathione Oxidized Glutathione Cystine Homocystine

Answer 49

Reduced Glutathione

Question 50

Glutamic Acid can be converted into alpha KG in one step which enzyme below is required for the alpha ketoglutarated to be covered to free glucose? ## Footnote Citrate Synthase PFK1 Pyruvate Kinase Pyruvate Carboxylase Aldolase

Answer 50

Aldolase — you need aldolase to make Fructose 1,6 BP

Question 51

Individual of mediterranean descent develops hemolytic anemia can still generate 5 carbon sugars from glucose requiring the participation of which of the following enzymes below? G6PDH G3PDH PFK1 Pyruvate Kinase F1,6BP

Answer 51

PFK1

Question 52

A drug developed to inhibit PEP carboxykinase would not block gluconeogenesis from which substrate? Aspartate Lactate Glutamate Glycerol Succinyl CoA

Answer 52

Glycerol

Question 53

New born exhibits hypoglycemia during periods of fasting. Enzyme assays reveal a defective phoshoglucomutase. This led to reduced glucose production from which on e of the following? Glycogen F6P Glycerol Lactate Aspartate G6P

Answer 53

Glycogen — only one requires phosphoglucomutase

Question 54

AN individual inherited a mutation in the gen for the UDP Glucose pyrophosphorylase such that it is 95% inactive? This is the consequence of which disorder? Inability to use either galactose or glycogen as an energy source Inability to make glycogen from any sugar or to utilize galactose as an energy source.

Answer 54

Inability to make glycogen from any sugar or to utilize galactose as an energy source.

Question 55

Individual has a mutation of UDPGLucose Epimerase. What is the likely consequence of this disorder?

Answer 55

Inability to use galactose as an energy source with no effect on the ability to use glycogen