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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. How does OTC def present
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
One
Two
Modifies N- oligosaccharides

2. What rxn creates ATP
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Malonyl coa
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

3. What is the activated carrier for aldehyddes
Wernicke - korsakoff - dry and wet beriberi
TTP
Phenylalanine
Anchor muscle fibers - primarily in skeletal and cardiac muscle

4. In what cells do the respiratory burst occur
PMNs
Uses ATP to add high energy phophate group onto substrate
Attachment of ubiquitin to defective proteins tag them for breakdown
Oxidative and nonoxidative - no ATP produced or used

5. How does warfarin work
Vit K antagonist
Phenylalanine hydroxylase
Liver hepatocytes and steroid producing cells of the adrenal cortex
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations

6. What does PURe As Gold and CUT The Py stand for
Each codon specifies only 1 amino acid
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Purines= A - G pyrimidine = C - T (U)

7. Which antifungal drugs work on microtubules
Hereditary spherocytosis
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Griseofulvin
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA

8. How is ammonium transported from muscle to the liver for urea cycle
Robertsonian translocation and mosaicism
Marasmus - muscle wasting
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
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra

9. Where do you find elastin and What does it do
Muscle
Schwann cells - lens - retina - kidneys
Chylomicrons
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

10. What tissues have both enzymes of sorbitol metabolism
G6PD
Liver - ovaries - seminal vesicles
Glucose - 2Pi - 2ADP - 2NAD+
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

11. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Mitochondria
Inc melt - dec fluidity

12. What happens with dry beriberi
Polyneuritis - symmetrical muscle wasting
PMNs
Inc glucagon - inc cAMP - inc PKA
Scrutinizes - hydrolyzes the bond

13. Describe robertsonian translocation
Four
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Cyclin dependent kinases;constitutive and inactive
Karyotyping

14. Fluorescent DNA or RNA probe binds to specific gene of interest - used for specific localization of genes and direct visualization of anomalies - like microdeletions - at molecular level
Degradation of TG stored in adipocytes
FISH
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Inc melt - dec fluidity

15. What is axonemal dynein
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
MEN - 2A and 2B with ret gene
Metanephrine

16. What does a defective Cl channel do
No - its non homologous
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

17. What is the breakdown product of epi
APC on chromosome 5
Transmitted only through mother - all offspring of affected females may show signs of disease
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Metanephrine

18. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
ADPKD
OTC has hyperammonemia - orotic aciduira does not
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

19. What are the findings in Down's syndrome
DTMP
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
The triphosphate bond

20. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Flagella - cilia - mitotic spindles
CGG

21. What does an umabiguous genetic code refer to...
O- oligosaccharaides
Each codon specifies only 1 amino acid
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Cofactor for LPL

22. What causes patau's syndrome and What is it
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Myeloperoxidase
Orotic acid to UMP

23. What substance inside the cells replenishes NADPH
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
G6PD

24. What enzyme results in classic galactosemia and What is the clinical
Conversion of NE to epi
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
In ER - glucose 6- P to glucose
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

25. How many ATP are produced by anearobic glycolysis per molecule of glucose
Conversion of NE to epi
Polycystic liver disease - berry aneurysm - mitral valve prolapse
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Two

26. inc glycogen in muscle but can't break it down - painful muscle cramps - myglobinuria with strenuous exercise - dz and enzyme

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27. How do cardia glycosides work
Deamination
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Phenylethamolamine N methyl transferase
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -

28. What is the function of biotin
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Arginine
Glycogen phosphorylase
ATP - citrate

29. What stretch of DNA that alters gene expression by binding of transcription factors
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Enhancers
Deamination
75 to 90 - cloverleaf

30. What are the blood glucose levels maintained by for days 1-3
Pyruvate to oxaloacetate (3C to 4C)
HMG- CoA synthase
Hepatic glycogenolysis - adipose tissue release of FFA - muslce and liver FFA - hepatic gluconeogenesis from peripheral tissue lactate and alanine and from adipose tissue glycerol and proprionyl - coA (odd chain FFA)
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

31. What is proteasomal degredation
Tryptophan
Carnitine acyltransferase I
CTG
Attachment of ubiquitin to defective proteins tag them for breakdown

32. What do neurofilaments stain for
Rotenone - CN- - antimycin A - CO
Muscle
Removes phosphate group from substrate
Neurons

33. What is the result of vit B5 def
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
HMG- CoA synthase
PCR - denaturation - annealing - elongation
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais

34. In mismatch repair - which strand is recognized and In what hereditary syndrome is this defective
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Dec DNA - dec lymphos leads to SCID
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Unmethylated - newly synthesized - HNPCC

35. characterize mitochondrial inheritance
Disorder of aromatic amino acid metabolism
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Williams syndrome
Transmitted only through mother - all offspring of affected females may show signs of disease

36. What is dominant negative mutation and give an example
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
HDL
Exons
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding

37. What kind of RNA is transported out of the nucleus
Binds to LDL receptor - mediates VLDL secretion
Adds an inorganic phosphate onto substrate without using ATP
Only processed RNA
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

38. What does apoCII do
APRT + PRPP
Cofactor for LPL
B48 - AIV - CII - E
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

39. What are the characteristics of prader willi syndrome How does it occur
Abnormal protein folding - degradation before reaching cell surface
HMG- CoA (HMG- CoA to mevalonate
Protective against malaria
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15

40. What 3 syndromes are associated with vit B1 def
Wernicke - korsakoff - dry and wet beriberi
GTP
Inc vit B6
HVA

41. What is variable expression and What is an example
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Result from phagocytic removal of heinz bodies my macs - G6PD def

42. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Ribose 5- P to PRPP
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
IMP precursor
Arginine

43. What is NADPH's role inside RBCs
Pseudomonas and s aureus
No - its non homologous
Four
Keep glutathione reduced so it can detoxify free radicals and peroxides

44. What are the only purely ketogenic amino acids
Four
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding
Lysine and leucine

45. What are purines made from
IMP precursor
Euchromatin
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Neurofibromatosis type 1 (von Recklinghausens disease)

46. What is a silent mutation
Antioxidant - protects RBCs and membrances from free radical damage
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Same AA - often base change in 3rd position of codon (tRNA wobble)
Lysine and leucine

47. What happens in hyperammonemia
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Marfans
Phenylketones in urine

48. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Transmitted only through mother - all offspring of affected females may show signs of disease
30 - 50 - 70
Reads usual codon but inserts wrong AA
LDL

49. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Locus heterogeneity - ocular albinism is x- linked recessive
Unwinds DNA template at replcation fork
More than 1 codon may code for the same amino acid
Essential fructosuria - fructokinase AR

50. What order kinetics does EtOH dehydrogenase have
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
GAA
Zero