Exam 2 Flashcards
(35 cards)
Which one of the following is NOT true regarding glycogen storage?
a) Glycogen to maintain blood glucose is stored in the liver
b) Glycogen stored in skeletal muscle is reserved for anaerobic metabolism IN THE MUSCLE only
c) Glycogen stored in liver is depleted within 12-24 hours
d) Glycogen stored in the muscle is depleted within 8 hours of vigorous exercise
d) Glycogen stored in the muscle is depleted within 8 hours of vigorous exercise…false….within 1 hour
Glycogen breakdown (glycogenolysis) is catalyzed by 3 enzymes. Which one is NOT of of those 3?
a) transketolase
b) glycogen phosphorylase
c) debranching enzyme
d) phosphoglucomutase
a) transketolase (a mutation in this enzyme and severe deficiency in thiamine (vitamin B1) causes Wernicke-Korsakoff syndrome)
b) glycogen phosphorylase (cleaves glucose from non-reducing end, releasing glucose-1-phosphate)
c) debranching enzyme (bifunctional enzyme which 1st cleaves and transfers 3 glucose from branchpoint to NR end then cleaves off single remaining glucose from branchpoint as free glucose)
d) phoshoglucomutase (converts glucose-1-phosphate to glucose-6-phosphate)
Debranching enzyme is bifunctional. What are the 2 functions of this enzyme?
1) transferase (cleaves and transfers 3 glucose from branchpoint to non-reducing end)
2) a1–6 glucosidase (cleaves single remaining glucose from branchpoint as free glucose)
Which one of the following is NOT true regarding glycogen synthesis?
a) reducing end is attached to the core protein
b) glycogen synthase adds glucose from UPD-glucose carrier to non-reducing end of growing glycogen chain
c) gylcogen-branching enzyme is used
d) glycogen synthase does not require a “primer”
d) glycogen synthase does not require a “primer”…false…its does and glycogenin provides that primer.
* The glycogenin dimer uses manganese as a cofactor
Which one of the following is NOT true?
a) Both skeletal muscles and the liver respond to both epinephrine and glucagon
b) glycogenesis is energy storage, while glycolysis is energy production
c) insulin promotes glycogen synthesis (fed state), while glucagon promotes glycogen breakdown (fasting state)
d) The pentose phosphate pathway has an oxidative and a non-oxidative phase
a) Both skeletal muscles and the liver respond to both epinephrine and glucagon…false….the liver has receptors for both, however, muscles only have receptors for epinephrine, not glucagon
Which of the following is NOT true?
a) Most free radicals are produced by cellular respiration
b) It is important to keep high levels of NADPH to protect RBC’s from oxidative stress
b) Deficiency in G6PDH is an X-linked disorder and protects AGAINST Malaria
c) A pt with a G6PDH deficiency should be on a low-dose aspirin regimen
c) A pt with a G6PDH deficiency should be on a low-dose aspirin regimen….false…exposure to aspirin can cause acute hemolysis (breakdown of RBC’s)
- *Pt’s with 6DPDH deficiency can experience acute hemolysis if exposed to these 5 chemicals (remember “FSNAP”)
1) Fava beans (divicine)
2) Sulfonamides (antibiotic type)
3) Napthalene (moth balls)
4) Aspirin (NSAIDS)
5) Primaquine (anti-malarial)
Which of the following is NOT true?
a) The non-oxidative phase of the pentose phosphate pathway recycles ribulose-5-phosphate to make glucose-6-phosphate in order to generate NADPH in abundance
b) The end product of the oxidative phase of the PPP is ribose-5-phosphate and 2 NADPH
c) The enzyme associated with the oxidative phase of the PPP is ribose-5-phosphate dehydrogenase
d) The enzymes associated with the non-oxidative phase of PPP is transketolase and transaldolase
c) The enzyme associated with the oxidative phase of the PPP is ribose-5-phosphate dehydrogenase…false…its glucose-6-phosphate dehydrogenase
Which one of the following is NOT true?
a) ribulose is the “ketose” form of ribose, while ribose is the “aldose” form of ribulose
b) transaldolase requires a cofactor
c) transketolase transfers 2 carbons, while transaldolase transfers 3 crabons
d) G6PDH deficiency is found in the same geographical region as HbS (sickle cell anemia)
b) transalsolase requires a cofactor…false…because the ketose group attaches directly to lysine residue of transaldolase
What are the 5 cofactors for PDH (pyruvate dehydrogenase)?
1) Thiamine-TPP (vit B1)
2) Riboflavin-FAD (vit B2)
3) Niacin-NAD+ (vit B3)
4) Panthothenate-Coenzyme A (vit B5)
5) lipoate
Which one of the following is not 1 of the 3 enzymes that make up the PDH (pyruvate dehydrogenase) complex?
a) E1: pyruvate dehydrogenase (TPP is a cofactor)
b) E2: Dihydrolipoyl transacetylase (coenzyme A and lipoate are components)
c) E3 Dihydrolipoyl dehydrogenase (FAD is a component and NAD+ is a cofactor)
d) all of the above are correct
d) all of the above are correct
Which one of the following is NOT true?
a) The starting components of pyruvate dehydrogenase are pyruvate and NAD+
b) The end products of pyruvate dehydrogenase are Acetyl-CoA and NADH
c) The products of the TCA cycle are: 1 CO2, 3 NADH, 1 FADH2, 1 GTP
d) all of the above are true
d) all of the above are true
Which one of the following is NOT one of the 3 enzymes that produce NADH in the TCA cycle?
a) isocitrate dehygrogenase
b) alpha ketoglutarate dehydrogenase complex
c) malate dehydrogenase
d) all of the above are all 3
d) all of the above are all 3
Match the enzymecomplex with its prosthetic group:
1) NADH dehydrogenase
2) Succinate dehydrogenase
3) ubiquinone/cytochrome c oxidoreductase
4) cytochrome c
5) cytochrome oxidase
a) Fe-S
b) Heme,Fe-S
c) Heme
1) NADH dehydrogenase–a) Fe-S
2) Succinate dehydrogenase–a) Fe-S
3) ubiquinone/cytochrome c oxidoreductase–b) Heme,Fe-S
4) cytochrome c–c) Heme
5) cytochrome oxidase–c) Heme
Which one of the following is NOT true?
a) Amphibolic refers to both catabolic and anabolic nature of TCA cycle intermediates
b) A Niacin deficiency is characterized by the 3 D’s: dermatitis, diarrhea, and dementia
c) Wilson’s disease is a copper overload and treated with chelation therapy
d) there are 2 iodine deficiency disorders, called goiter and cretinism caused by a deficient synthesis of thyroxine (T4) and triiodothyrinine (T3)
e) deficiency in vitamin A is related to spina bifida
e) deficiency in vitamin A is related to spina bifida…false…vitamin A is a major teratogen and spina bifida is caused by a folate (vit B9) deficiency
Which one of the following is NOT true?
a) The polyol pathway increases NADPH levels needed to neutralize reactive oxygen species (ROS’s)
b) The hydroxyl radical (HO*) is the most reactive free radical
c) Retinal is a component of rhodopsin
d) Lipid (fat) soluable vitamins are: A,D,E, and K
a) The polyol pathway increases NADPH levels needed to neutralize reactive oxygen species (ROS’s)…false…it contributes to ROS’s by depleting NADPH
Which one of the following is NOT true?
a) a deficiency in vitamin A can lead to night blindness
b) antioxidant vitamins are A,C, and E
c) Vitamin K is an anti-clotting vitamin
d) Rickets and osteomalacia are vitamin D deficiencies
c) Vitamin K is an anti-clotting vitamin…false…its function is to help with blood clotting
Which one of the following is NOT true?
a) Beriberi is a deficiency in thiamine (B1)
b) Pellagra is a deficiency in Niacin (B3)
c) spina bifida is caused from too much folate (B9) in pregnancy
d) Pernicious anemia is a deficiency in cobalamin (B12)
c) spina bifida is caused from too much folate (B9) in pregnancy…false…spina bifida is caused from folate deficiency during pregnancy
Which one of the following is NOT true?
1) Wilson’s disease presents with Kayser-fleisher rings
2) Lathyrism is a pyroxidine (B6) deficiency
3) Linolenic acid is the least important fatty acid
4) Barth sydrome is an x-linked disorder caused by a defect in cardolipin processing protein
3) Linolenic acid is the least important fatty acid…false…its the most important. It is an Omega 3 that is anti-arrhythmic, anti-infammatory, and anti- thrombotic
Which one of the following is NOT true?
a) the ETC (electron transport chain) occurs in the inner membrane of the mitochondria
b) The goal of the ETC is to produce a proton gradient that drives ATP synthase
c) The 2 mobile carriers in the ETC are ubiquinone and cytochrome C
d) cytochrome C carries electrons between complex II and complex III
d) cytochrome C carries electrons between complex II and complex III….false, its between complex III and IV
Which one of the following is NOT true?
a) cyanide blocks ETC, therefore blocking ATP production
b) 2 disorders caused by mitochondrial genome mutations are LHON and MERFF (Lebers hereditary optic neuropathy and Myoclonic epilepsy and regged-red fiber)
c) cytochrome C acts as a trigger for apoptosis by stimulating the activation of a family of proteases called capsases
d) all of the above are true
d) all of the above are true
Which of the following is NOT true?
a) sphingolipids are derived from fat
b) Tay-Sachs disease is a lysosomal storage disorder
c) Pt’s with Tay-sachs disease present with cherry red maculae
d) bile salts are the most abundant product of cholesterol
a) sphingolipids are derived from fat….false…they are derived from serine
Which one of the following is NOT true?
a) Eicosinoids are derived from arachodonic acid
b) During apoptosis of a cell, phosphatidylserine flips to the outside to signal macrophages
c) Botox promotes exocytosis
d) Lipid rafts are stable microdomains of cholesterol and sphingolipids that serve as sites for lipid-linked protein attachment to the lipid bilayer
c) Botox promotes exocytosis…false…Botox blocks the signal for exocytosis
Describe the 6 integral membrane proteins
1 and 2: single transmembrane helix
- *1: amino terminal outside the cell
- *2: amino terminal inside the cell
3: single protein, multiple transmembrane helices
4: multiple proteins, single transmembrane proteins
5: lipid-linked proteins
6: both transmembrane and lipid-linked domains
(T/F) People who inherit 2 defective (mutant) genes for the LDL receptor have receptors that function poorly or not at all creating excessively high levels of LDL in their blood and predisposes them to atherosclerosis and heart attacks. This disorder is called Familial hypercholesteremia
true
