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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 function of Zinc
Dopamine beta hydroxylase
P2 +2pq+ = 1
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Stop codon is recognized by release factor - and completed protein is released from ribosome

2. What is pleiotropy and given an example
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Purines= A - G pyrimidine = C - T (U)
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes

3. Which aspect of the spliceosome do patients with lupus make antibodies against
Robertsonian translocation and mosaicism
SnRNPs
Tryptophan
Zero

4. What happens in vit D def
African Americans and Asians
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
RRNA

5. What is the RDE of de novo purine synthesis
Von gierkes - glucose 6 phosphatase
Oxidized hemoglobin precipiated within RBCs
Glutamine PRPP amidotransferase
BOne

6. What is the activated carrier for phosphoryl
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Dopa decarboxylase
PFK - rate limiting enzyme
ATP

7. 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
Conversion of NE to epi
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Autosomal recessive diseases
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

8. 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
Alkaptonuria - may have debiliating arthralgias
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Supply sufficient glucose to brain and RBCs and to preserve protein
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

9. What form of amino acids are found in proteins
L form
Phosphofructokinase 1
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Tropoelastin with fibrillin scafolding

10. What substances are uncouling agents
Activates LCAT
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
2 -4 DNP - aspirin
Glycine

11. Which enzyme involved in RNA synthesis does not require a template
Zero
IDL
Dopamine beta hydroxylase
Poly A polymerase - signal is AAUAA

12. Type IV BM
Protein
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
4 under the floor
RER

13. What happens in vit D excess
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Same AA - often base change in 3rd position of codon (tRNA wobble)
Removes phosphate group from substrate

14. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
B12 and folate
Paclitaxel
1 ring
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

15. What step of uric acid synthesis does xanthine oxidase catalyze
Promotor - TATA box - and CAAT box - AT rich
The triphosphate bond
Hypoxanthine to xanthing and xanthine to uric acid
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

16. What is the physiologic role of dystrophin
HMG- CoA synthase
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Achondroplasia
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)

17. Type IV collagen
Q -
Dopa decarboxylase
Core proteins
Basement membrane or basal lamina

18. What is the source of energy in the fasting state between meals
Kidney - ears - eyes
Adenosine to inosine
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

19. What substance in egg whites binds biotin
MEN - 2A and 2B with ret gene
Fibrofatty replacement of muscle - cardiac myopathy
Site of steroid synthesis and detoxification of drugs and poisons
Avidin

20. When does aspartate enter the urea cycle
DNA
After citruline
Active secretion in lungs and GI - reabsorbs in skin
RER

21. In eukaryotes - What does RNA poly II make
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Lysine and leucine
Active secretion in lungs and GI - reabsorbs in skin
MRNA

22. recurrent pulmonary infxns in CF are due to what organisms
Dec DNA - dec lymphos leads to SCID
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Pseudomonas and s aureus
Change resulting in early stop codon

23. What substances induce phosphofructokinase
Change resulting in early stop codon
AMP - fructose 2 -6 BP
Phosphofructokinase 1
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

24. What are covalent alterations
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Microtubules
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Phosphorylation - glycosylation - hydroxylation

25. What enzyme results in classic galactosemia and What is the clinical
Mebendazole/thiabendazole
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
Palate - facial and cardiac defects
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

26. What does PURe As Gold and CUT The Py stand for
Result from phagocytic removal of heinz bodies my macs - G6PD def
Purines= A - G pyrimidine = C - T (U)
Comlex II
Neither of 2 alleles is dominant - blood groups

27. What substance inside the cell serves to oxidize glutatione
Microtubules
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Attachment of ubiquitin to defective proteins tag them for breakdown
Peroxide

28. What is the amino acid precursor for histamine
Uses ATP to add high energy phophate group onto substrate
Histidine
Mucus secreting globlet cells and antibody secreting plasma cells
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR

29. In what direction are DNA and RNA synthesized

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30. Acetyl - CoA carboxylase catalyzes what rxn
Niacin - constituent of NAD and NADP - derived from tryptophan
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
75 to 90 - cloverleaf
Acetyl - CoA to malonyl - CoA (2C to 3C)

31. Gene imprinting implies that How many alleles are active at a single locus
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Dermatitis - alopecia - enteritis
One
Fasting

32. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
Arg and his inc in histones Which bind negatively charged DNA
HDL
Schwann cells - lens - retina - kidneys

33. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
Microarrays
1 kind with multiple subunits
Hypoglycemia
African Americans and Asians

34. What produces NADPH
Microarrays
HMP shunt
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

35. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
PMNs
RER
Williams syndrome

36. 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
Isocitrate dehydrogenase
Phenylalanine
Base + ribose + phosphate (3' -5') phosphodiester bond

37. characterize x linked recessive
Must be both activated and inactivated for cell cycle to progress
Stored ATP - creatine phosphate - anaerobic glycolysis
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 orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive

38. What are the findings in PKU
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Diphyllobothrium latum
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor

39. cell signaling defect of fibroblast growth factor (FGF) receptor 3 - results in dwarfism - short limbs - head/trunk nl size - associated with advanced paternal age
40 - 60 - 80
Achondroplasia
Pseudomonas and s aureus
Ribos first then deoxyribos with ribonucleotide reductase

40. What creates the musty body odor in PKU
Essential fructosuria - fructokinase AR
Biotin
Disorder of aromatic amino acid metabolism
Conversion of NE to epi

41. What CETP do
Activates LCAT
Intermediate filaments
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Scrutinizes - hydrolyzes the bond

42. What is the TX for CF and What does it do
Silencers
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Free ribosomes
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

43. Where is vit B12 found
Ile - phe - thr - trp
Infection - free radicals generated by inflammatory response
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Dermatitis - alopecia - enteritis

44. What is dominant negative mutation and give an example
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
CAG
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
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

45. What initiates protein synthesis
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Abnormal protein folding - degradation before reaching cell surface
Ribose 5- P to PRPP

46. What enzymes metabolize fatty acids and amino acids
Foliage - small reserve in liver - eat green leaves
High output cardiac failure - dilated cardiomyopathy - edema
Acetoacetate and beta hydroxybutyrate
Krabbes - galactocerebrosidase - galactocerebroside - AR

47. What regulates whether FBPase -2 or PFK-2 is active
DsRNA promotes degradation of target mRNA knocking down gene expression
MRNA
Liver hepatocytes and steroid producing cells of the adrenal cortex
Protein kinase A

48. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Eu - methionine - pro - formyl - methionine
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
FMR1 gene - methylation - associated with chromosomal breakage

49. Milder form of type I with nl blood lactate levels - dz and enzyme

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50. What does the golgi assemble proteoglycans from
Core proteins
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Enhancers
Sulfation