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 a northern blot use as its sample
Orotic acid to UMP
RNA
PFK - rate limiting enzyme
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

2. What rxn creates ATP
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
RRNA
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

3. What is the wernicke - korsakoff clinical picture
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Mcardle's - skeletal muscle glycogen posphorylase
Hyperlipidemia
Night blindness - dry skin

4. What is the activated carrier for electrons
Liver - also in kidney and gut epithelium
Binds 50S - blocking translocation
NADH - NADPH - FADH2
Exons

5. What does primase do
Makes RNA primer on which DNA poly III can initiate replication
Alpha1 antitrypsin
Eu - methionine - pro - formyl - methionine
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond

6. What happens do glycogen in skeletal muscle during exercise
Myeloperoxidase
Glycogenolysis to form glucose
HMG- CoA (HMG- CoA to mevalonate
Euchromatin

7. What metabolic rxns occur in both the cytoplasm and mitochondria
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Transfers methyl units
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Phenylketones in urine

8. cardiomegaly - systemic findings leading to early death - dz and enzyme

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

9. What does a kinase do
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Proline and lysine - vit C
Uses ATP to add high energy phophate group onto substrate
IMP precursor

10. What is mosaicism and give an example
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Proline and lysine - vit C
Consesus sequenec of base pairs
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

11. How do you diagnose CFTR
Alkaptonuria - may have debiliating arthralgias
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
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Inc Cl - in sweat

12. 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
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Males are infertile due to bilateral absence of vas deferens

13. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
Citrate - acetyl coa from mito to cyto
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Exercise: inc NAD/NADH - inc ADP - inc Ca
Oligomycin

14. What are the symptoms of vit A def
Vincritsine/vinblastine
Microtubules
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Night blindness - dry skin

15. What kind of RNA is transported out of the nucleus
Oxidized hemoglobin precipiated within RBCs
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Only processed RNA
ATP and methionine

16. recurrent pulmonary infxns in CF are due to what organisms
Kwashiorkor - small child with swollen belly
Pseudomonas and s aureus
Facial flushing
Neurons

17. What are the glucogenic/ketogenic amino acids
Ile - phe - thr - trp
ATP - citrate
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

18. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
DsRNA promotes degradation of target mRNA knocking down gene expression
Glucose - 2Pi - 2ADP - 2NAD+
OTC has hyperammonemia - orotic aciduira does not

19. What is the energy source after day 3 of starvation
RRNA
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
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
Night blindness - dry skin

20. What substances induce phosphofructokinase
Modifies N- oligosaccharides
2pq
Catabolic processes to carry reducing equivalents away as NADH
AMP - fructose 2 -6 BP

21. What are purines made from
Fibrofatty replacement of muscle - cardiac myopathy
Liver - ovaries - seminal vesicles
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
IMP precursor

22. What happens in termination of proteins synthesis
Phenylketones in urine
Stop codon is recognized by release factor - and completed protein is released from ribosome
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
More than 1 codon may code for the same amino acid

23. What does the primary transcript combine with to form the spliceosome
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
SnRNPs and other proteins
Williams syndrome
Fed

24. Why does alpha amanitin cause liver failure and Where is it found
P2 +2pq+ = 1
Purines= A - G pyrimidine = C - T (U)
Glucose -6 phosphate
Inhibits RNA polymerase II - found in death cap mushrooms

25. What does a phosphorylase do
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Wernicke - korsakoff - dry and wet beriberi
Adds an inorganic phosphate onto substrate without using ATP

26. What two amino acids are required druing periods of growth and why
TRNA
HMG- CoA reductase
Arg and his inc in histones Which bind negatively charged DNA
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

27. CF - is AR deletion In what gene On what chromosome resulting in a deletion inf what?
Each codon specifies only 1 amino acid
CGG
CFTR gene - 7 - Phe 508
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)

28. What do neurofilaments stain for
Heterochromatin = HighlyCondensed
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Mediates extra remnant take up
Neurons

29. Why is albinism inheritnace varialbe due to...
Locus heterogeneity - ocular albinism is x- linked recessive
Particular sequence of DNA where replicatino begins - may be single of multiple
Base + ribose
Arginine

30. What is the TX for CF and What does it do
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
The triphosphate bond
Lysine and arginine
Foliage - small reserve in liver - eat green leaves

31. In a marathon Where does energy come from
Degredation of TG circulating in chylomicrons and VLDLs
Glycogen and FFA oxidation; glucose conserved for final sprinting
5' to 3'
Carnitine shuttle - acyl - coa from cyto to mito

32. What are the findings in Lesch - Nyhan
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Basement membrane or basal lamina

33. What does arsenic do and What are th results of poisoning
Defect in fibrillin
Scrutinizes - hydrolyzes the bond
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

34. The pyruvate dehydrogenase complex serves In what reaction: products
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Procollagen - triple helix of 3 alpha collagen chains
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Acetly- CoA - CO2 - NADH

35. What does the start codon code for in eukaryotes and prokaryotes
P+q = 1
Procollagen - triple helix of 3 alpha collagen chains
Eu - methionine - pro - formyl - methionine
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate

36. How does abetalipoproteinemia present and What is the defect
MRNA
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
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Poly A polymerase - signal is AAUAA

37. What happens in folate def
OTC has hyperammonemia - orotic aciduira does not
Medial dorsal nucleus of thalamus - mamillary bodies
Eu - methionine - pro - formyl - methionine
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs

38. What converts DOPA to dopamine
Antibiotic use or excessive ingestion of raw eggs
Silencers
Dopa decarboxylase
Phenylalanine hydroxylase

39. How does cytosine become uracil
Site of steroid synthesis and detoxification of drugs and poisons
Deamination
Terminal regions - tropocollagen
The triphosphate bond

40. What enzyme converts phenylalanine to tyrosin
Only processed RNA
NADH - NADPH - FADH2
Adds an inorganic phosphate onto substrate without using ATP
Phenylalanine hydroxylase

41. How does insulin inhibit glycogenolysis
Elastase - inhibited by alpha1 antitrypsin
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Ketone - methyl

42. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Oxalacetate
No
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

43. In what cell is collagen synthesis initiated
40 - 60 - 80
Fibroblast
Promotor - TATA box - and CAAT box - AT rich
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

44. What are Heinz bodies
Phosphofructokinase 1
Hereditary spherocytosis
Oxidized hemoglobin precipiated within RBCs
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

45. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Disorder of aromatic amino acid metabolism
Cri du chat
Inc melt - dec fluidity
Dec methionine - inc cystiene - inc B12/folate

46. If two alleles are present - but the active allele is deleted - what happens
Disease
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Tryosine hydroxylase
Ile - phe - thr - trp

47. What happens in carnitine def
Acetyl - CoA carboxylase (ACC)
Assistance of upper extremities to stand up
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

48. What does universal genetic code refer to and What are some exception
Promotor - TATA box - and CAAT box - AT rich
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

49. How does chloramphenicol work
Inhibits 50S peptidyltransferase
Achondroplasia
Active secretion in lungs and GI - reabsorbs in skin
Protein

50. What does Ehlers Danlos cause and why
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
ATP - citrate