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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 NADPH's role inside RBCs
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
Degredation of dietary TG in small intestine
Keep glutathione reduced so it can detoxify free radicals and peroxides
Scrutinizes - hydrolyzes the bond

2. Who typically has lactase def
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Krabbes - galactocerebrosidase - galactocerebroside - AR
Comlex II
African Americans and Asians

3. What rxn creates ATP
Neither of 2 alleles is dominant - blood groups
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Diphyllobothrium latum

4. What co - factors are required for the pyruvated dehydrogenase complex
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Isocitrate dehydrogenase
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Kwashiorkor - small child with swollen belly

5. peripheral neuropathy of hands/feet - angiokeratomas - CV/renal disease - dz - def enzyme - acc substrate - inherit
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Proton gradient
Lactate
Phenylketones in urine

6. What is DNA cloning and How do you do it?
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Von Gierke's - Pompe - Cori - McArdle
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Change resulting in early stop codon

7. If two alleles are present - but the active allele is deleted - what happens
Adds 2 carbon with the help of biotin
Antibiotic use or excessive ingestion of raw eggs
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Disease

8. What is dominant negative mutation and give an example
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
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
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

9. what happens in acyl coa dehyrdogenase def
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Inc dicarboxylic acids - dec in glucose and ketones
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Connective tissue

10. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Hypoxanthine to xanthing and xanthine to uric acid
Autosomal recessive diseases
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Base + ribose

11. 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
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Lariat shape in order and remove intron precisely and join 2 exons

12. What is the RDE of gluconeogenesis
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Fructose 1 -6 bisphosphate
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Removes phosphate group from substrate

13. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Inc glucagon - inc cAMP - inc PKA
ATP hyrdolysis couple to energetically unfavorable rxns
Ca/calmodulin in muscle to coordinate with muscle activity
Conversion of NE to epi

14. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
Initiate chains
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Mediates chylomicron secretion
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

15. What is the TX for CF and What does it do
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
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Fibrofatty replacement of muscle - cardiac myopathy

16. In what direction are DNA and RNA synthesized

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17. What ribosomes do eukaryotes have
40 - 60 - 80
Proline and glycine (non glycosylated forms)
Debranching enzyme
APKD1 on chromosome 16

18. What happens in the first stage of collagen synthesis - and Where does it happen
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Abnormal protein folding - degradation before reaching cell surface
Uses ATP to add high energy phophate group onto substrate
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)

19. What is the TX for pyruvate dehydrogenase deficiency
Binds 50S - blocking translocation
Failure to track objects or develop a social smile
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Alcohol version of glucose - can trap glucose in cell - aldose reductase

20. What converts DOPA to dopamine
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
No
4 under the floor
Dopa decarboxylase

21. What collagen type is most frequently affected in ehlers danlos and What are common complications
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
III - joint dislocation - anuerysms - organ rupture

22. What happens in folate def
Proline and lysine - vit C
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Mediates extra remnant take up
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs

23. Acetyl - CoA carboxylase catalyzes what rxn
Ketone - methyl
Glycogenolysis to form glucose
Acetyl - CoA to malonyl - CoA (2C to 3C)
Fructose 1 -6 bisphosphate

24. What do the single stranded binding proteins do
Seals.
Site of steroid synthesis and detoxification of drugs and poisons
Prevent strands from reannealing
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

25. What is the TX for PKU
Base + ribose + phosphate (3' -5') phosphodiester bond
Avidin
B48 - AIV - CII - E
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

26. What is the structure of elastin
P+q = 1
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Tropoelastin with fibrillin scafolding

27. What are the priorities for the body in fasting and starvation
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
HVA
Supply sufficient glucose to brain and RBCs and to preserve protein
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

28. depression - progressive dementia - choreiform movements - caudate atrophy and dec levels of GABA and ACH in the brain
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Huntingtons
Conversion of NE to epi

29. What causes B12 def
Conversion of NE to epi
Post to neg
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
DNA

30. What is the RDE of the HMP shunt
Creat a nick in the helix to relieave supercoils created during replication
Dermatitis - glossitis - and diarrhea
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Glucose 6 phosphate dehydrogenase (G6PD)

31. What does lactase deficiency cause
Terminal regions - tropocollagen
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

32. What inhibits pyruvate kinase
Von hippel lindau - 3
Medial dorsal nucleus of thalamus - mamillary bodies
ATP and alanine
GAA

33. What is the fxn of vit D
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Facial flushing
Rotenone - CN- - antimycin A - CO
Glycogen phosphorylase

34. What is heteroplasmy
Acetly- CoA - CO2 - NADH
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Same as sprint + OXPHOS
Glycogen phosphorylase

35. What is the function of Zinc
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
HDL
Same AA - often base change in 3rd position of codon (tRNA wobble)
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

36. What does a carboxylase do
Adds 2 carbon with the help of biotin
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Protective against malaria
CGG

37. The pyruvate dehydorgenase complex serves In what reaction: reactants
Mediates extra remnant take up
Pyruvate - NAD+ - CoA
Carbomoyl phosphate synthetase II
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)

38. what disease can cause pellagra
B48 - AIV - CII - E
UGA - UAA and UAG
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate

39. What are the symptoms of vit A def
Night blindness - dry skin
Same as sprint + OXPHOS
Acetoacetate and beta hydroxybutyrate
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

40. How does chloramphenicol work
Inhibits 50S peptidyltransferase
Must be both activated and inactivated for cell cycle to progress
Phenylethamolamine N methyl transferase
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

41. Which direction does dynein go
Biotin
HMG- CoA (HMG- CoA to mevalonate
Post to neg
Failure to track objects or develop a social smile

42. What is Gowers maneuver
Assistance of upper extremities to stand up
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Flank pain - hematuria - HTN - progressive renal failure
Keep glutathione reduced so it can detoxify free radicals and peroxides

43. What are the only purely ketogenic amino acids
Lysine and leucine
UGA - UAA and UAG
Ketone - methyl
Neg to pos

44. What substance accumulates in galactokinase def and What is the clinical picture
Ile - phe - thr - trp
Males are infertile due to bilateral absence of vas deferens
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

45. What test is used for B12 def
Schilling test
Seals.
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
After citruline

46. What converts NE to epi
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Phenylethamolamine N methyl transferase
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

47. What is the RDE of fatty acid synthesis
Acetyl - CoA carboxylase (ACC)
Specific glycosylases - AP endonuclease
40 - 60 - 80
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin

48. What does helicase do
Unwinds DNA template at replcation fork
Protective against malaria
Base + ribose + phosphate (3' -5') phosphodiester bond
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine

49. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
III - joint dislocation - anuerysms - organ rupture
APC on chromosome 5
OTC has hyperammonemia - orotic aciduira does not
Protein kinase A

50. 90% of ADPKD cases are due to a mutation In what gene
CFTR gene - 7 - Phe 508
APKD1 on chromosome 16
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Stop codon is recognized by release factor - and completed protein is released from ribosome