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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 two pathways is carbomoyl phosphate involved in - and what enzyme deficiency leads to a build of carbamoyl phosphate leading to what element in pyrimidine synthesis
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Neither of 2 alleles is dominant - blood groups
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway

2. What does a decrease in decrease in NADPH lead to and why
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
OTC has hyperammonemia - orotic aciduira does not
Glycogen synthase

3. Mild Hurlurs + aggressive behavior no corneal clouding
Scrutinizes - hydrolyzes the bond
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Colchicine
Phenytoin - MTX - and sulfonamides

4. What does hepatic TG lipase do
Silencers
Degradation of TG remaining in IDL
Initiate chains
Liver - also in kidney and gut epithelium

5. What is the origin of replication
Particular sequence of DNA where replicatino begins - may be single of multiple
Polyneuritis - symmetrical muscle wasting
Arginine
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

6. What is the TX for PKU
Disorder of aromatic amino acid metabolism
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Asp and Glu
4 under the floor

7. What is the structure of elastin
Kidney - ears - eyes
Metanephrine
Tropoelastin with fibrillin scafolding
The triphosphate bond

8. Why enzyme breaks down elastin and what enzyme inhibits it
Elastase - inhibited by alpha1 antitrypsin
HGPRT - defective purine salvage - excess uric acid production
Schwann cells - lens - retina - kidneys
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

9. What is the energy source for tRNA actication (charging)
Lariat shape in order and remove intron precisely and join 2 exons
ATP
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
Phenylketones in urine

10. What is RNAi used for
Consesus sequenec of base pairs
Wobble
DsRNA promotes degradation of target mRNA knocking down gene expression
Mebendazole/thiabendazole

11. What causes Marfan syndrome
Adds an inorganic phosphate onto substrate without using ATP
Mediates extra remnant take up
Tropoelastin with fibrillin scafolding
Defect in fibrillin

12. What are bite cells and when do you see them
Oral uridine administration
Ile - phe - thr - trp
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Result from phagocytic removal of heinz bodies my macs - G6PD def

13. Which amino acids are elastin rich in
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Proline and glycine (non glycosylated forms)
Glycine - aspartate - glutamine
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations

14. What happens do glycogen in skeletal muscle during exercise
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Asp and Glu
32 - malate aspartate shuttle
Glycogenolysis to form glucose

15. What are the fat soluble vitamins and What does their absorption depend on...
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Thymic - parathyroid and cardiac
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
THFs

16. Where do you find elastin and What does it do
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Griseofulvin
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

17. What happens in vit B2 def
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
THFs
DNA
ADPKD

18. several distinct syndromes characterized by familial tumors of endocrine glands including pancreas - parathyroid - pituitary - thryoid and adrenal medulla - disorders and gene association
Medial dorsal nucleus of thalamus - mamillary bodies
Dec methionine - inc cystiene - inc B12/folate
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
MEN - 2A and 2B with ret gene

19. What is the amino acid precuror for creatine - urea and nitric oxide
Arginine
Liver and leafy veggies
Abnormal protein folding - degradation before reaching cell surface
X linked frame shif mutation

20. Where is fructose 1 -6 bisphosphatase found and What does it do
ATP - citrate
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Glycine

21. What are the findings in orotic aciduria
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Heterochromatin = HighlyCondensed
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

22. What form of amino acids are found in proteins
Modifies N- oligosaccharides
L form
Vit K antagonist
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

23. in a 100 meter sprint Where does energy come from
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Stored ATP - creatine phosphate - anaerobic glycolysis
Malonyl coa
Phenylalanine hydroxylase

24. What co - factors are required for the pyruvated dehydrogenase complex
Q -
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Removal of N or C termal propeptides from zymogens to generate mature proteins
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

25. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
Sucrose = glucose + fructose - lactose = glucose + galactose
X linked frame shif mutation
Neg to pos
Wrinkles and acne

26. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Superoxide dismutase
X linked frame shif mutation
Oligomycin
HMG- CoA (HMG- CoA to mevalonate

27. What enzyme def can cause emphysema
Each codon specifies only 1 amino acid
Alpha1 antitrypsin
NF2 on chromosome 22
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis

28. congenital deficiency of homogentisic acid oxidase in the degradative pathway of tyrosine to fumarate leading to dark connective tissue - brown pigmented sclera - urine turns black on standing - dz and worst complication
Infection - free radicals generated by inflammatory response
Conversion of NE to epi
Alkaptonuria - may have debiliating arthralgias
Activates LCAT

29. What is the RDE of de novo pyrimidine synthesis
Carbomoyl phosphate synthetase II
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Targets the proteins for lysosome
Alanine

30. What causes Down syndrome
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Kidney - ears - eyes
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

31. nucleotide repeat for fredreich's ataxia
GAA
Breaks down acyl - coa to acetyl coa groups in mito
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Disease

32. How is Lesch Neyhan inherited
Antibiotic use or excessive ingestion of raw eggs
X- linked recessive
Modifies N- oligosaccharides
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

33. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Achondroplasia
Inc glucagon - inc cAMP - inc PKA
Pyruvate to oxaloacetate (3C to 4C)
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

34. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Tropoelastin with fibrillin scafolding
Proline and glycine (non glycosylated forms)
Nature and severity of phenotype vary from 1 individual to another - NF type 1

35. What is the function of biotin
DsRNA promotes degradation of target mRNA knocking down gene expression
Inc CPK and muscle biopsy
PFK - rate limiting enzyme
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

36. What components come together to make S- adenosyl methionine
Avidin
Malapsorption syndromes like sprue or CF or mineral oil intake
Diphyllobothrium latum
ATP and methionine

37. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
Cleft palate - cardiac abnl - pregs test
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Alpha - ketoglutarate dehydrogenase complex
ATP

38. How is orotic aciduria inherited
AR
Metanephrine
Essential fructosuria - fructokinase AR
Lysine and leucine

39. What induces pyruvate kinase
F16BP
Orotic acid to UMP
Wernicke - korsakoff - dry and wet beriberi
Neimann - pick - sphingomyelinase - sphingomyelin - AR

40. Mediates reverse cholesterol transport from periphery to liver - acts as respository for apoC an apoE - secreted from both liver and small intestine
Targets the proteins for lysosome
HDL
Glycine
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

41. What is the activated carrier for 1 carbon units
THFs
SnRNPs and other proteins
APKD1 on chromosome 16
Hyperlipidemia

42. What is kartageners syndrome
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Wrinkles and acne

43. What enzyme does fructose metabolism bypass to reach glycolysis
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
PFK - rate limiting enzyme
Karyotyping
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

44. What substances inhibit phosphofructokinase -1
Robertsonian translocation and mosaicism
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
ATP - citrate
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx

45. bilateral acoustic schwannomas - juvenile cataracts
NF2 on chromosome 22
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Arg and his inc in histones Which bind negatively charged DNA
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis

46. What is the activated carrier for electrons
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
II - VII - IX - X (1972) protein C and S
HVA
NADH - NADPH - FADH2

47. What does biotin def cause
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Dermatitis - alopecia - enteritis
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue

48. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Hypoxanthine to xanthing and xanthine to uric acid
Oligomycin
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

49. This is the site where negative regulators bind
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Males are infertile due to bilateral absence of vas deferens
Silencers

50. What 3 amino acids are necessary for purine synthesis
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Glycine - aspartate - glutamine
II - VII - IX - X (1972) protein C and S
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase