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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. What is the amino acid precuror for creatine - urea and nitric oxide
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
2pq
Arginine
Thymic - parathyroid and cardiac

2. How is vit D stored
25OHD3
Williams syndrome
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

3. Which antifungal drugs work on microtubules
Poly A polymerase - signal is AAUAA
Griseofulvin
CAG
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

4. What happens on the nonoxidative arm of the HMP shunt and What is the key enzyme and cofactor
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Phenylalanine
Assistance of upper extremities to stand up

5. What does a southern blot use as its sample
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
DNA
CTG
Fibrofatty replacement of muscle - cardiac myopathy

6. What enzyme becomes essential in PKU
Keep glutathione reduced so it can detoxify free radicals and peroxides
Tyrosine
30 - glycerol -3- phosphate shuttle
Phenylethamolamine N methyl transferase

7. What inhibits pyruvate kinase
2 rings
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
ATP and alanine
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

8. What are the two transgenic strategies in mice
2pq
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Rb and p53
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

9. What are the characteristics of angelmans syndrome and How does it occur
Early in life - AR - inability to synthesize lipoproteins due to def in apoB100 and B48 - intestinal biopsy shows accumulation within enterocytes due to inability to export absorbed lipid as chylomicrons - failure to thrive - steatorrhea - acanthocyt
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
B-100 - CII and E
Essential fructosuria - fructokinase AR

10. What is the purpose of the HMP shunt
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
MRNA
Acetyl - CoA to malonyl - CoA (2C to 3C)

11. What form of amino acids are found in proteins
Oxidative and nonoxidative - no ATP produced or used
African Americans and Asians
Glycogen synthase
L form

12. Gene imprinting implies that How many alleles are active at a single locus
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Alpha1 antitrypsin
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
One

13. What does arsenic do and What are th results of poisoning
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
N to C
Niacin - constituent of NAD and NADP - derived from tryptophan
Inhibits the Na/K pump by binding the K side

14. What is the breakdown product of dopamine
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
HVA
Reads usual codon but inserts wrong AA
HMG- CoA synthase

15. What is the energy source for translocation
Degredation of dietary TG in small intestine
NADPH
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
GTP

16. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
LCAT (lecithin cholesterol acyltransferase)
Microtubules
Dopa decarboxylase

17. What happens in a B12 def
Transmitted only through mother - all offspring of affected females may show signs of disease
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Thymic - parathyroid and cardiac
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

18. What are the findings in PKU
DsRNA promotes degradation of target mRNA knocking down gene expression
Ile - phe - thr - trp
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Dopamine beta hydroxylase

19. How is Lesch Neyhan inherited
NF2 on chromosome 22
X- linked recessive
Liver hepatocytes and steroid producing cells of the adrenal cortex
Dec methionine - inc cystiene - inc B12/folate

20. What happens in zinc def
They yield only acetyl - CoA equivalents
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
High output cardiac failure - dilated cardiomyopathy - edema
Acetyl - CoA to malonyl - CoA (2C to 3C)

21. What step of uric acid synthesis does xanthine oxidase catalyze
Glutamine PRPP amidotransferase
Alpha 1 -6 and alpha 1 -4
Hypoxanthine to xanthing and xanthine to uric acid
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage

22. What does the TCA cycle produce per 1 acetyl CoA
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Degredation of dietary TG in small intestine
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Acetly- CoA - CO2 - NADH

23. What are the physical findings of fragile x syndrome
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Medial dorsal nucleus of thalamus - mamillary bodies
No

24. What enzyme converts phenylalanine to tyrosin
Phenylalanine hydroxylase
Inc melt - dec fluidity
Not all individuals with a mutant genotype show the mutant phenotype
Acetyl - CoA

25. What is the origin of replication
Mucus secreting globlet cells and antibody secreting plasma cells
Inc vit B6
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Particular sequence of DNA where replicatino begins - may be single of multiple

26. What neuroanatomical strutures are injured in wernicke - korsakoff
5' to 3'
MRNA
Transmitted only through mother - all offspring of affected females may show signs of disease
Medial dorsal nucleus of thalamus - mamillary bodies

27. Do balanced translocations cause abnl phenotype
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Modifies N- oligosaccharides
Sulfation
No

28. Where is fructose 1 -6 bisphosphatase found and What does it do
Cytosol - F 1 -6 BP to fructose 6 Phosphate
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
X linked frame shif mutation
Glutamate

29. What does amino acid catabolsim results in the formation of what?
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Post to neg
Hyperlipidemia
UGA - UAA and UAG

30. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
In ER - glucose 6- P to glucose
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Hereditary spherocytosis

31. What activates the pyruvate dehydrogenase complex
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
HDL
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Exercise: inc NAD/NADH - inc ADP - inc Ca

32. What converts limit dextran to glucose
Debranching enzyme
Mitochondria
Microtubules
Oxidative and nonoxidative - no ATP produced or used

33. An inability to convert orotic acid to UMP would be caused by a deficiency either of which two enzymes

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34. What do def in in enzymes of gluconeogenesis cause
Hypoglycemia
Binds to LDL receptor - mediates VLDL secretion
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
CGG

35. trinucleotide repeat for huntingtons
75 to 90 - cloverleaf
CAG
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Inc dicarboxylic acids - dec in glucose and ketones

36. Where do you find elastin and What does it do
Inc insulin - dec cAMP - dec PKA
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Lactate
Pyroxidine - converted to pyroxidine phosphate a cofactor used in transamination - decarboxylation - glycogen phosphorylase - cystathionine synthesis and heme synthesis - required for synthesis of niacin and tryptophan

37. What is the RDE of de novo purine synthesis
Fed
Males are infertile due to bilateral absence of vas deferens
Glutamine PRPP amidotransferase
NAD+

38. What ribosomes do prokaryotes have
Keep glutathione reduced so it can detoxify free radicals and peroxides
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Transmitted only through mother - all offspring of affected females may show signs of disease
30 - 50 - 70

39. In eukaryotes - What does RNA poly I make
Cre - lox system
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Night blindness - dry skin
RRNA

40. What is incomplete penetrence and give an example
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Not all individuals with a mutant genotype show the mutant phenotype
Malapsorption syndromes like sprue or CF or mineral oil intake
Protein kinase A

41. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Change resulting in early stop codon
Fibrofatty replacement of muscle - cardiac myopathy
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

42. What does hormone sensitive lipase do
Degradation of TG stored in adipocytes
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Connective tissue

43. What enzyme degrades a small amount of glycogen in lysosomes
Cri du chat
FISH
Alpha 1 -4 glucosidase
Mcardle's - skeletal muscle glycogen posphorylase

44. cardiomegaly - systemic findings leading to early death - dz and enzyme

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45. What collagen type is most frequently affected in ehlers danlos and What are common complications
III - joint dislocation - anuerysms - organ rupture
Polyneuritis - symmetrical muscle wasting
Males are infertile due to bilateral absence of vas deferens
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

46. Which cells are rich in smooth ER
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
2 -4 DNP - aspirin
Liver hepatocytes and steroid producing cells of the adrenal cortex
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

47. What are the names and sources of the two types of vit D found in nature
2pq
IDL
Pyruvate to oxaloacetate (3C to 4C)
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

48. What are pyrimidines made from
Cartilage - hyaline - vitreous body - nucleus pulposus
Adenosine to inosine
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Orotate precursor - with PRPP added later

49. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
OTC has hyperammonemia - orotic aciduira does not
Vit K antagonist
Alpha 1 -4 glucosidase
Uses ATP to add high energy phophate group onto substrate

50. What drugs can cause folate def
Phenytoin - MTX - and sulfonamides
Glycine - aspartate - glutamine
Epithelial cells
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis