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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. For eukaryotes - Where does replication begin?
Occurs when cells in the body have different genetic makeup - can be germline mosaic - which may produce a disease that is not carried by parents somatic cells - lyonization - random X inactivation in females
Consesus sequenec of base pairs
NADPH
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty

2. What are the symptoms of vit A excess
III - joint dislocation - anuerysms - organ rupture
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
Arginine
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

3. How do odd chain fatty acids participate in gluconeogenesis
Changed AA (convservative - new AA is similar in chemical structure)
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
HGPRT - defective purine salvage - excess uric acid production
Prevent strands from reannealing

4. What happens in termination of proteins synthesis
Modifies N- oligosaccharides
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)
BOne
Stop codon is recognized by release factor - and completed protein is released from ribosome

5. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Phenylketones in urine
Acetyl - CoA
9+2 arrangement of microtubules

6. What does CATCH 22 stand for and What causes is...
Kidney - ears - eyes
ADPKD
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

7. How do labile celss grow and regenerate and What are examples
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Alpha and beta tubulin - dimers have two GTP bound

8. What is the defect in cystinuria
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Free ribosomes
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

9. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
High output cardiac failure - dilated cardiomyopathy - edema
Inc insulin - dec cAMP - dec PKA
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais

10. What substances induce phosphofructokinase
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
After citruline
Free ribosomes
AMP - fructose 2 -6 BP

11. What does the golgi do to sugars in proteoglycans and of selected tyrosine on proteins
Essential fructosuria - fructokinase AR
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Sulfation
2pq

12. What is the function of biotin
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Binds to LDL receptor - mediates VLDL secretion
Mcardle's - skeletal muscle glycogen posphorylase

13. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Catabolic processes to carry reducing equivalents away as NADH
Alanine

14. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Ketone - methyl
Disease
Terminal regions - tropocollagen
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

15. What do def in in enzymes of gluconeogenesis cause
X linked frame shif mutation
Procollagen - triple helix of 3 alpha collagen chains
Hypoglycemia
Targets the proteins for lysosome

16. Which part of the DNA binds RNA polymerase and multiple other TFs upstream from gene locus
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Eu - methionine - pro - formyl - methionine
Promotor - TATA box - and CAAT box - AT rich
Wrinkles and acne

17. How do macrolides and clindamycin work
FISH
Binds 50S - blocking translocation
Abnormal protein folding - degradation before reaching cell surface
Zero

18. What are the blood glucose levels maintained by for days 1-3
Antioxidant - protects RBCs and membrances from free radical damage
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)
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Breaks down acyl - coa to acetyl coa groups in mito

19. When are glycogen reserves depleted
After day 1
Marasmus - muscle wasting
Inc glucagon - inc cAMP - inc PKA
Grows slowly - collapses quickly

20. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Glucose 6 phosphatase

21. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Adenosine to inosine
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
Microarrays

22. What is the longest time of RNA and shortest
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Bruton's agammaglobulinemia - wiskott - aldrich - fabrys disease - G6PD def - ocular albinism - Lesch - Nyhan syndrome - Duchenne and Becker Muscular Dystrophy - hunter's syndrome - hemophilia A and B
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
MRNA - tRNA

23. What is the fxn of vit D
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Stop codon is recognized by release factor - and completed protein is released from ribosome
Oxidizes substrate

24. What is trimming
Tuberous sclerosis
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Removal of N or C termal propeptides from zymogens to generate mature proteins
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor

25. How do stable (quiescent) cells grow and regenerate and What are examples
Griseofulvin
BOne
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
CGG

26. What does hormone sensitive lipase do
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Degradation of TG stored in adipocytes
In ER - glucose 6- P to glucose
Inc CPK and muscle biopsy

27. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
HMG- CoA synthase
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Intermediate filaments

28. What occurs to oxaloacetate in starvation and DKA
Tyrosine
Heterochromatin = HighlyCondensed
Dermatitis - glossitis - and diarrhea
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

29. What is variable expression and What is an example
ATP and methionine
Eu - methionine - pro - formyl - methionine
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

30. What converts DOPA to dopamine
Dopa decarboxylase
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Abnormal protein folding - degradation before reaching cell surface
CFTR gene - 7 - Phe 508

31. What enzyme results in classic galactosemia and What is the clinical
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Disorder of aromatic amino acid metabolism
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Diphyllobothrium latum

32. Name 5 drugs that interfere with nucleotide synthesis
Glycine
Medial dorsal nucleus of thalamus - mamillary bodies
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR

33. What enzyme converts adenine to AMP
30 - glycerol -3- phosphate shuttle
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
APRT + PRPP

34. What happens on the nonoxidative arm of the HMP shunt and What is the key enzyme and cofactor
Attachment of ubiquitin to defective proteins tag them for breakdown
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Zero
Semiconservative - continuous and discontinuous strands (okazaki fragments)

35. what disease can cause pellagra
SnRNPs and other proteins
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Oxidizes substrate

36. What is the RDE of the HMP shunt
Neg to pos
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Mcardle's - skeletal muscle glycogen posphorylase
Glucose 6 phosphate dehydrogenase (G6PD)

37. What is the amino acid precursor for histamine
Marfans
Histidine
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea

38. What catacholamine step is SAM required for
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
L form
Conversion of NE to epi
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

39. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Actin and myosin
Wrinkles and acne
Superoxide dismutase

40. What tissues have only aldose reductase
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Schwann cells - lens - retina - kidneys
Purines= A - G pyrimidine = C - T (U)

41. What order kinetics does EtOH dehydrogenase have
NAD+
Neuralgia
Liver - also in kidney and gut epithelium
Zero

42. In a marathon Where does energy come from
ATP - citrate
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Glycogen and FFA oxidation; glucose conserved for final sprinting

43. What happens at the smooth ER
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Site of steroid synthesis and detoxification of drugs and poisons
Biotin
Carnitine shuttle - acyl - coa from cyto to mito

44. What initiates protein synthesis
Defect in fibrillin
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
HMG- CoA synthase
SNP

45. What are the findings in Down's syndrome
Transmitted only through mother - all offspring of affected females may show signs of disease
Liver hepatocytes and steroid producing cells of the adrenal cortex
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
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

46. Which antihelminthe drugs work on microtubules
Q -
Sucrose = glucose + fructose - lactose = glucose + galactose
Mebendazole/thiabendazole
Alpha 1 -6 and alpha 1 -4

47. What is the structure of elastin
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Orotate precursor - with PRPP added later
Tropoelastin with fibrillin scafolding
Palate - facial and cardiac defects

48. What does primase do
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
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
Oxidized hemoglobin precipiated within RBCs
Makes RNA primer on which DNA poly III can initiate replication

49. What is regeneration of methionine depedent on...
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
B12 and folate
Attachment of ubiquitin to defective proteins tag them for breakdown
B100

50. How do you diagnose CFTR
Inc Cl - in sweat
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
CTG
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood