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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 RDE of the HMP shunt
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Degradation of TG remaining in IDL
Glucose 6 phosphate dehydrogenase (G6PD)
Active secretion in lungs and GI - reabsorbs in skin

2. What defects characterize DiGeorge syndrome
Initiate chains
Thymic - parathyroid and cardiac
Consesus sequenec of base pairs
B12 and folate

3. Which direction does dynein go
Post to neg
Disorder of aromatic amino acid metabolism
RRNA
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes

4. What does vit E def cause
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Colchicine
Orotic acid to UMP

5. What substances inhibit phosphofructokinase -1
Cartilage - hyaline - vitreous body - nucleus pulposus
Dopa decarboxylase
P2 +2pq+ = 1
ATP - citrate

6. characterize x linked recessive
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
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
Glycogen phosphorylase
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

7. 1 g of protein or cabrohydrate = ?kcal
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Arg and his inc in histones Which bind negatively charged DNA
Four
Phenylethamolamine N methyl transferase

8. Which cells are rich in smooth ER
Phenylketones in urine
Liver hepatocytes and steroid producing cells of the adrenal cortex
Inc melt - dec fluidity
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

9. What are possilbe presentation for galactokinase def
AR
Lysine and leucine
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Failure to track objects or develop a social smile

10. What is used to diagnose muscular dystrophies
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Inc CPK and muscle biopsy
Two
Sulfation

11. What is NADPH used for
Anabolic processes as a supply of reducing equivalents
Changed AA (convservative - new AA is similar in chemical structure)
HMG- CoA synthase
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

12. What causes B12 def
IMP precursor
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
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
Makes RNA primer on which DNA poly III can initiate replication

13. What happens with wet beriberi
Alpha1 antitrypsin
High output cardiac failure - dilated cardiomyopathy - edema
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Ribos first then deoxyribos with ribonucleotide reductase

14. What happens in carnitine def
Glycogenolysis to form glucose
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
1/4 of offspring from 2 carrier parents are affected - often enzyme def - usually only seen in 1 generation - often more sever than AD - presents in childhood
ATP

15. FAP is due to deletion On what gene On what chromosome
Kidney - ears - eyes
Oxidized hemoglobin precipiated within RBCs
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
APC on chromosome 5

16. What does an umabiguous genetic code refer to...
Modifies N- oligosaccharides
Each codon specifies only 1 amino acid
FMR1 gene - methylation - associated with chromosomal breakage
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma

17. When does aspartate enter the urea cycle
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
After citruline
Antioxidant - facilitates iron absorption by keeping iron in the Fe2+ reduced state - necessary for hydroxylation of proline and lysine collagen bridges - necessary for dopamine beta hydroxylase which converts DA to NE
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

18. What enzyme converts glucose 1 p to UDP glucose
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
Oxidizes substrate
UDP glucose pyrophosphorylase
Particular sequence of DNA where replicatino begins - may be single of multiple

19. What causes Edwards syndrome and What is it
Degredation of TG circulating in chylomicrons and VLDLs
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year

20. What is the activated carrier for phosphoryl
40 - 60 - 80
ATP
Essential fructosuria - fructokinase AR
Transfers methyl units

21. What are the purely ketogenic amino acids
MEN - 2A and 2B with ret gene
Leu - lys
Karyotyping
LCAT (lecithin cholesterol acyltransferase)

22. What is imprinting and give an example

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23. What enzyme converts phenylalanine to tyrosin
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Phenylalanine hydroxylase
Type II
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome

24. What drugs can cause folate def
Pyruvate - NAD+ - CoA
Mucus secreting globlet cells and antibody secreting plasma cells
30 - glycerol -3- phosphate shuttle
Phenytoin - MTX - and sulfonamides

25. What are the priorities for the body in fasting and starvation
Supply sufficient glucose to brain and RBCs and to preserve protein
EtOH dehydrogenase and acetaldehyde dehydrogenase
In ER - glucose 6- P to glucose
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

26. what findings are associated with marfans
Arg - lys - his - arg is most basic - has has no charge at body pH
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Connective tissue
Actin and myosin

27. What does a phosphorylase do
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Adds an inorganic phosphate onto substrate without using ATP
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact

28. What is the RER called in neurons and What is made there
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Nissl body - enzyme and NTs
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Actin and myosin

29. What kind of RNA is transported out of the nucleus
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
Only processed RNA
Protein kinase A
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

30. What is regeneration of methionine depedent on...
CAG
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Mebendazole/thiabendazole
B12 and folate

31. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Oxidizes substrate
Pyruvate - NAD+ - CoA
1 -25 OH2 D3 = calcitriol
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

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

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33. What part of the pre mRNA contains the actual genetic information coding for protein
Base + ribose + phosphate (3' -5') phosphodiester bond
Polycystic liver disease - berry aneurysm - mitral valve prolapse
NADPH
Exons

34. Where is vit A found in the diet
Met - val - arg his
Liver and leafy veggies
Exons
Polyneuritis - symmetrical muscle wasting

35. What is the RDE of cholesterol synthesis
UDP glucose pyrophosphorylase
HMG- CoA reductase
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Q -

36. What is the longest time of RNA and shortest
HGPRT - defective purine salvage - excess uric acid production
MRNA - tRNA
Debranching enzyme
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

37. What does the golgi assemble proteoglycans from
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Core proteins
Must be both activated and inactivated for cell cycle to progress
AMP - fructose 2 -6 BP

38. What is the energy source in the fed state right after a meal
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Skin
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Glycolysis and aerobic respiration

39. Broadly - What can cause fat - soluble vitamin deficiencies
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Malapsorption syndromes like sprue or CF or mineral oil intake
Inc CPK and muscle biopsy
PMNs

40. What occurs to oxaloacetate in starvation and DKA
Oxidized hemoglobin precipiated within RBCs
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Disease

41. What is a frame shift
Ribose 5- P to PRPP
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Abnormal protein folding - degradation before reaching cell surface
Conversion of NE to epi

42. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Oxidative and nonoxidative - no ATP produced or used
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Dec methionine - inc cystiene - inc B12/folate
BOne

43. What is disulfiram used for
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms

44. What does the CFTR channel do in the lungs - GI tract and skin
B6
Active secretion in lungs and GI - reabsorbs in skin
Euchromatin
Catabolic processes to carry reducing equivalents away as NADH

45. Which phase of the HMP shunt is reversible and Which is irreversible
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Oxidative is irreversible
B-100 - CII and E

46. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Acetyl - CoA
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Epithelial cells
Cytosol

47. What substance in egg whites binds biotin
Avidin
MRNA - tRNA
Zero
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

48. What does amino acid catabolsim results in the formation of what?
Stop codon is recognized by release factor - and completed protein is released from ribosome
5' to 3'
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Scrutinizes - hydrolyzes the bond

49. What is the order of severity for the different types of mutations
1 ring
Arginine
Nonsense > missense > silent
No - its non homologous

50. What does inc phenylalanine lead to...
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Enhancers
Phenylketones in urine
Mediates chylomicron secretion