Test your basic knowledge |

Biochemistry

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What does arsenic do and What are th results of poisoning
Pyruvate - NAD+ - CoA
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais

2. What does apoE do
Ketone - methyl
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Oxidative and nonoxidative - no ATP produced or used
Mediates extra remnant take up

3. What are uncoupling agents
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
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
ATP hyrdolysis couple to energetically unfavorable rxns
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

4. What is the amino acid precursor for GABA and glutathione
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Glutamate
Mcardle's - skeletal muscle glycogen posphorylase
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

5. What happens in a B12 def
Achondroplasia
Nonsense > missense > silent
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

6. What does the start codon code for in eukaryotes and prokaryotes
Oxalacetate
Eu - methionine - pro - formyl - methionine
Lacks glucose 6 phophatase
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly

7. Acetyl - CoA carboxylase catalyzes what rxn
Acetyl - CoA to malonyl - CoA (2C to 3C)
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Neuralgia
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA

8. What shuttle is involved in fatty acid synthesis and What does it move From where to where
APKD1 on chromosome 16
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Ribos first then deoxyribos with ribonucleotide reductase
Citrate - acetyl coa from mito to cyto

9. What enzyme converts phenylalanine to tyrosin
Nine
Paclitaxel
Phenylalanine hydroxylase
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

10. What is the RDE of ketogenesis
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
HMG- CoA synthase
Alkaptonuria - may have debiliating arthralgias
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

11. What metabolic rxns occur in the cytoplasm
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Transfers methyl units
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

12. What does DNA ligase do
Changed AA (convservative - new AA is similar in chemical structure)
Seals.
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Methionine encode by only 1 codon (AUG)

13. What feedback inhibits hexokinase
Glucose -6 phosphate
Flank pain - hematuria - HTN - progressive renal failure
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
CGG

14. How do stable (quiescent) cells grow and regenerate and What are examples
Phenylethamolamine N methyl transferase
Debranching enzyme
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
RNA poly II

15. Where is glucokinase found - What are the Km and Vmax - and what induces it
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Alanine
Superoxide dismutase

16. What substance accumulates in galactokinase def and What is the clinical picture
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Isocitrate dehydrogenase
25OHD3
Modifies N- oligosaccharides

17. The pyruvate dehydorgenase complex serves In what reaction: reactants
32 - malate aspartate shuttle
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Pyruvate - NAD+ - CoA

18. Mediates reverse cholesterol transport from periphery to liver - acts as respository for apoC an apoE - secreted from both liver and small intestine
HDL
APC on chromosome 5
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Rotenone - CN- - antimycin A - CO

19. Mild Hurlurs + aggressive behavior no corneal clouding
MRNA - tRNA
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Unwinds DNA template at replcation fork
Muscle

20. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
RRNA
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Base + ribose + phosphate (3' -5') phosphodiester bond

21. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
They yield only acetyl - CoA equivalents
Peroxide
Fibroblast

22. What fxn does glucokinase serve in the liver
Karyotyping
Must be both activated and inactivated for cell cycle to progress
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Phosphorylation - glycosylation - hydroxylation

23. What is the RER called in neurons and What is made there
Adipse tissue stores - keton bodies become the main source of energy fo the brain and heart - after these are depleted - vital protein degradation accelerates - leading to organ failure and death
Lariat shape in order and remove intron precisely and join 2 exons
Nissl body - enzyme and NTs
APKD1 on chromosome 16

24. How many rings do pyrimidines have
Intermediate filaments
Liver - ovaries - seminal vesicles
1 ring
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR

25. Why can't muscle produce in gluconeogenesis
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Initiate chains
Lacks glucose 6 phophatase
Conversion of NE to epi

26. How is Lesch Neyhan inherited
X- linked recessive
Glucose -6 phosphate
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

27. How do odd chain fatty acids participate in gluconeogenesis
Conversion of NE to epi
RER
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two

28. What happens to oxaloacetate in alcholism
Oral uridine administration
Basement membrane or basal lamina
Glycogenolysis to form glucose
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

29. What causes B12 def
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Dermatitis - enteritis - alopecia - adrenal insuff
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss

30. A small proportion of Down syndrome is due to What two genetic events
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Griseofulvin
Robertsonian translocation and mosaicism

31. Name as many x- linked recessive disorders as you can

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

32. How many nucTIDEs is a tRNA and What does the secondary sturcture form
9+2 arrangement of microtubules
ATP - citrate
75 to 90 - cloverleaf
Neurons

33. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Lysine and arginine
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

34. What converts tyrosine to DOPA
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Tryosine hydroxylase
Hypoxanthine to xanthing and xanthine to uric acid
Vincritsine/vinblastine

35. What converts limit dextran to glucose
Lacks glucose 6 phophatase
Glycogen synthase
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Debranching enzyme

36. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Glycine
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Fibrofatty replacement of muscle - cardiac myopathy
Cartilage - hyaline - vitreous body - nucleus pulposus

37. In which structures do you find microtubules
Dopa decarboxylase
Colchicine
Flagella - cilia - mitotic spindles
PFK - rate limiting enzyme

38. What do def in in enzymes of gluconeogenesis cause
Vit K antagonist
Mebendazole/thiabendazole
Biotin
Hypoglycemia

39. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
CTG
Intermediate filaments
After day 1
Phenylketones in urine

40. Which type of chromatin is less condensed - transcriptionally active - sterically accesible
Pyruvate - NAD+ - CoA
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Euchromatin
Each codon specifies only 1 amino acid

41. RNA poly can't proofread - but What can it do
Facial flushing
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Inc CPK and muscle biopsy
Initiate chains

42. What is the defectin IV - hypertriglyceridemia
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Heterochromatin = HighlyCondensed
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL

43. Where are cytosolic and organellar proteins made
APRT + PRPP
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Free ribosomes
P+q = 1

44. What does glycosylation of pro alpha chian yield and What is the structure
B100 and E
Procollagen - triple helix of 3 alpha collagen chains
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
HMP shunt

45. What does apoB100 do
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Binds to LDL receptor - mediates VLDL secretion
Rotenone - CN- - antimycin A - CO
Oligomycin

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

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

47. What is the result of vit B5 def
Dermatitis - enteritis - alopecia - adrenal insuff
HMG- CoA reductase
Familial hypercholesterolemia - hyperlipidemia type IIA
Biotin

48. What does DNA poly I do?
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Inc dicarboxylic acids - dec in glucose and ketones
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
30 - 50 - 70

49. In eukaryotes - What does RNA poly I make
Neuralgia
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Consesus sequenec of base pairs
RRNA

50. Why does alpha amanitin cause liver failure and Where is it found
Inhibits RNA polymerase II - found in death cap mushrooms
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
VMA
HDL