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Biochemistry

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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1. facial lesions - hypopigmented 'ash leaf spots -' cortical and retinal hamartomas - seizures - mental retardation - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas - inc risk of astrocytomas
Tuberous sclerosis
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Transfers methyl units
Polyneuritis - symmetrical muscle wasting

2. What liberates glucose from glucose 6 P
Glucose 6 phosphatase
Rotenone - CN- - antimycin A - CO
Robertsonian translocation and mosaicism
Kidney - ears - eyes

3. What are the results of pancreatic insuff in CF
Degredation of TG circulating in chylomicrons and VLDLs
Malabsorption and steatorrhea (ADEK)
Karyotyping
Intermediate filaments

4. What are the function of vit C
Antioxidant - facilitates iron absorption by keeping iron in the Fe2+ reduced state - necessary for hydroxylation of proline and lysine collagen bridges - necessary for dopamine beta hydroxylase which converts DA to NE
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
P+q = 1

5. Describe the replication fork
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Glycogenolysis to form glucose
Y shaped region along the DNA template where leading nad lagging strands are synthesized

6. what happens in acyl coa dehyrdogenase def
Inc dicarboxylic acids - dec in glucose and ketones
Cleft palate - cardiac abnl - pregs test
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Modifies N- oligosaccharides

7. What is the energy source in the fed state right after a meal
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Glycolysis and aerobic respiration
Must be both activated and inactivated for cell cycle to progress
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA

8. What does inc phenylalanine lead to...
Procollagen - triple helix of 3 alpha collagen chains
Change resulting in early stop codon
Phenylketones in urine
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer

9. What is the defect in II A familial hypercholesterolemia
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle
Cofactor for LPL
Acetyl - CoA to malonyl - CoA (2C to 3C)

10. What happens to oxaloacetate in alcholism
Alpha 1 -4 glucosidase
Phosphorylation - glycosylation - hydroxylation
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Neither of 2 alleles is dominant - blood groups

11. How many rings do pyrimidines have
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Pyruvate - NAD+ - CoA
1 ring

12. What is the breakdown product of NE
VMA
Comlex II
O- oligosaccharaides
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

13. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Base + ribose + phosphate (3' -5') phosphodiester bond
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
X linked frame shif mutation
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

14. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
40 - 60 - 80
EtOH dehydrogenase and acetaldehyde dehydrogenase
Glucose 6 phosphatase
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle

15. Very Poor Carbohydrate Metabolism stands for 4 of the glycogen storage diseases - What are thy
Von Gierke's - Pompe - Cori - McArdle
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Degredation of TG circulating in chylomicrons and VLDLs

16. nucleotide repeat for fragile x
Niacin - constituent of NAD and NADP - derived from tryptophan
CGG
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR

17. What happens in a B12 def
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
Familial hypercholesterolemia - hyperlipidemia type IIA
Eu - methionine - pro - formyl - methionine
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

18. trinucleotide repeat fo myotonic dystrophy
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Glycogen and FFA oxidation; glucose conserved for final sprinting
CTG
Keep glutathione reduced so it can detoxify free radicals and peroxides

19. What does NADPH oxidase deficiency result in and why
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Avidin
Dermatitis - enteritis - alopecia - adrenal insuff

20. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Heterochromatin = HighlyCondensed
CGG

21. What does fomepizole do
RRNA
Vit K antagonist
Debranching enzyme
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

22. What are the glucogenic essential amino acids
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Krabbes - galactocerebrosidase - galactocerebroside - AR
Met - val - arg his
Dermatitis - enteritis - alopecia - adrenal insuff

23. What are the symptoms of vit A def
Orotic acid to UMP
Night blindness - dry skin
Neurofibromatosis type 1 (von Recklinghausens disease)
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

24. This is the site where negative regulators bind
Degredation of dietary TG in small intestine
Silencers
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin
Glucose - 2Pi - 2ADP - 2NAD+

25. What does vit B3 def result in
Exercise: inc NAD/NADH - inc ADP - inc Ca
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Fibroblast
Schilling test

26. What is the most common urea cycle disorder and What is the mode of inheritance?
Four
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Schwann cells - lens - retina - kidneys
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

27. What do def in in enzymes of gluconeogenesis cause
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Hypoglycemia

28. What co - factors are required for the pyruvated dehydrogenase complex
X- linked recessive
Vit K antagonist
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
PFK - rate limiting enzyme

29. What does hormone sensitive lipase do
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Degradation of TG stored in adipocytes
Myeloperoxidase
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

30. Milder form of type I with nl blood lactate levels - dz and enzyme
Glycogenolysis to form glucose
Comlex II
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Hereditary spherocytosis

31. nucleotide repeat for fredreich's ataxia
Nissl body - enzyme and NTs
GAA
2pq
Unmethylated - newly synthesized - HNPCC

32. What is imprinting and give an example
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
P2 +2pq+ = 1

33. What happens in zinc def
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Hypoglycemia
Glutamate

34. Which phase of the HMP shunt is reversible and Which is irreversible
Glucose 6 phosphate dehydrogenase (G6PD)
Oxidative is irreversible
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Disease

35. Infection with what organism can cause B12 def
Type II
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Diphyllobothrium latum
NADH - NADPH - FADH2

36. in a 100 meter sprint Where does energy come from
Stored ATP - creatine phosphate - anaerobic glycolysis
Palate - facial and cardiac defects
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
32 - malate aspartate shuttle

37. What drugs can cause folate def
1 -25 OH2 D3 = calcitriol
Phenytoin - MTX - and sulfonamides
Antibiotic use or excessive ingestion of raw eggs
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

38. What collagen type is most frequently affected in ehlers danlos and What are common complications
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Vit K antagonist
III - joint dislocation - anuerysms - organ rupture
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

39. What are the results of CF on male fertility
Cytosol
Males are infertile due to bilateral absence of vas deferens
Core proteins
FAP

40. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
Oligomycin
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
Nonsense > missense > silent
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

41. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Essential fructosuria - fructokinase AR
Wrinkles and acne
Vit K antagonist
1 ring

42. What can excess vit B3 cause
Facial flushing
Huntingtons
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

43. In what direction are DNA and RNA synthesized
In ER - glucose 6- P to glucose
Glucose 6 phosphate dehydrogenase (G6PD)
HGPRT - defective purine salvage - excess uric acid production
5' to 3'

44. What does hartnups disease cause
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Oligomycin
SnRNPs
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

45. What is kartageners syndrome
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Consesus sequenec of base pairs
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Liver - also in kidney and gut epithelium

46. Where is PEP carboxykinase found - What does it do - and What does it require
Inc insulin - dec cAMP - dec PKA
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

47. Type IV BM
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
4 under the floor
Site of steroid synthesis and detoxification of drugs and poisons

48. What does the TCA cycle produce per 1 acetyl CoA
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Ribos first then deoxyribos with ribonucleotide reductase
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
High output cardiac failure - dilated cardiomyopathy - edema

49. bilateral acoustic schwannomas - juvenile cataracts
Diphyllobothrium latum
NF2 on chromosome 22
Dec DNA - dec lymphos leads to SCID
Neuralgia

50. What defects characterize DiGeorge syndrome
Thymic - parathyroid and cardiac
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Same AA - often base change in 3rd position of codon (tRNA wobble)
VLDL

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