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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 neuroanatomical strutures are injured in wernicke - korsakoff
MEN - 2A and 2B with ret gene
Medial dorsal nucleus of thalamus - mamillary bodies
30 - 50 - 70
Acetyl - CoA to malonyl - CoA (2C to 3C)

2. What are the findings in PKU
Glycolysis and aerobic respiration
Carbomoyl phosphate synthetase II
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL

3. What is a missense mutation
By inhibiting formation of the initiation complex and cause misreading of mRNA
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Cri du chat
Changed AA (convservative - new AA is similar in chemical structure)

4. Which carbon bears the triphosphate and the energy source for bond formation

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5. What does DNA poly I do?
CGG
Sulfation
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

6. Which enzyme involved in RNA synthesis does not require a template
MRNA
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Orotic acid to UMP
Poly A polymerase - signal is AAUAA

7. What is the RDE of de novo pyrimidine synthesis
PFK - rate limiting enzyme
Dec methionine - inc cystiene - inc B12/folate
RNA poly II
Carbomoyl phosphate synthetase II

8. What substances inhibit phosphofructokinase -1
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Skin
ATP - citrate
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

9. What substance inside the cell reduces glutatione
NADPH
Dermatitis - alopecia - enteritis
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

10. What is the RER called in neurons and What is made there
Mcardle's - skeletal muscle glycogen posphorylase
SnRNPs
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
Nissl body - enzyme and NTs

11. What is loss of heterozygosity and give an example
Protein kinase A
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
Locus heterogeneity - ocular albinism is x- linked recessive
Mediates extra remnant take up

12. Adenosine deaminase deficiency is an important cause of what immunodeficiency?
40 - 60 - 80
Dec DNA - dec lymphos leads to SCID
Krabbes - galactocerebrosidase - galactocerebroside - AR
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle

13. What are the function of vit C
Breaks down acyl - coa to acetyl coa groups in mito
Fed
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
Thymic - parathyroid and cardiac

14. What clotting factors require vit K
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
Targets the proteins for lysosome
Y shaped region along the DNA template where leading nad lagging strands are synthesized
II - VII - IX - X (1972) protein C and S

15. What is the source of energy in the fasting state between meals
Result from phagocytic removal of heinz bodies my macs - G6PD def
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele

16. What is the RDE of glycogen synthesis
Autosomal recessive diseases
VLDL
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Glycogen synthase

17. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
No
Lactate
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

18. What creates the musty body odor in PKU
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Disorder of aromatic amino acid metabolism
ATP and alanine
B12 and folate

19. What enzyme adds Cl - to the H202 to makes bleach
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Myeloperoxidase
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

20. How do glucagon/epi lead to glycogenolysis
Uses ATP to add high energy phophate group onto substrate
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Tyrosine
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis

21. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
TTP
Males are infertile due to bilateral absence of vas deferens
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

22. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Intermediate filaments
NF2 on chromosome 22
Neurons

23. What is trimming
Inhibits the Na/K pump by binding the K side
Metanephrine
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Removal of N or C termal propeptides from zymogens to generate mature proteins

24. What fxn does glucokinase serve in the liver
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
BOne
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Colchicine

25. What does Alports syndrome cause and why
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Lysine and leucine
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
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

26. What causes Down syndrome
Abnormal protein folding - degradation before reaching cell surface
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

27. Which phase of the HMP shunt is reversible and Which is irreversible
Oxidative is irreversible
Isocitrate dehydrogenase
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Rotenone - CN- - antimycin A - CO

28. What is the fxn of vit D
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Von gierkes - glucose 6 phosphatase

29. What collagen type is most frequently affected in ehlers danlos and What are common complications
III - joint dislocation - anuerysms - organ rupture
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Anabolic processes as a supply of reducing equivalents
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

30. How many ATP are produced by anearobic glycolysis per molecule of glucose
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
G6PD
Two
Dopa decarboxylase

31. What is the energy source after day 3 of starvation
Oral uridine administration
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
Disease
N to C

32. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Inc glucagon - inc cAMP - inc PKA
2 rings
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle

33. How many ATP are created by aerobic metobolism of glucose in muslce via what shuttle
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
FISH
30 - glycerol -3- phosphate shuttle
Supply sufficient glucose to brain and RBCs and to preserve protein

34. What is chediak higashi
Glucose 6 phosphatase
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Oxidized hemoglobin precipiated within RBCs

35. What makes up a nucleoside
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Attachment of ubiquitin to defective proteins tag them for breakdown
Base + ribose
Vit K antagonist

36. What apolipoproteins are on IDL
Glutamate
B100 and E
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Sucrose = glucose + fructose - lactose = glucose + galactose

37. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
IDL
Phosphorylation - glycosylation - hydroxylation
One

38. What are the complications/signs of familial hypercholesterolemia
Alanine
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Medial dorsal nucleus of thalamus - mamillary bodies
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

39. How do fluoroquinolones work
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Kwashiorkor - small child with swollen belly
Inhibit DNA gyrase specific for prokaryotic topoisomerase

40. What converts limit dextran to glucose
Debranching enzyme
Keep glutathione reduced so it can detoxify free radicals and peroxides
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Inc glucagon - inc cAMP - inc PKA

41. What drugs can cause folate def
2 -4 DNP - aspirin
Phenytoin - MTX - and sulfonamides
Cleft palate - cardiac abnl - pregs test
Anabolic processes as a supply of reducing equivalents

42. What is regeneration of methionine depedent on...
Nonsense > missense > silent
DNA
B12 and folate
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

43. What is the breakdown product of epi
EtOH dehydrogenase and acetaldehyde dehydrogenase
Cyclin dependent kinases;constitutive and inactive
Metanephrine
25OHD3

44. What is the function of folic acid
After day 1
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Removal of N or C termal propeptides from zymogens to generate mature proteins
Neimann - pick - sphingomyelinase - sphingomyelin - AR

45. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
Grows slowly - collapses quickly
F16BP
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Liver - also in kidney and gut epithelium

46. What does the start codon code for in eukaryotes and prokaryotes
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Eu - methionine - pro - formyl - methionine
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
CGG

47. How is ATP used by the cell
Initiate chains
Proline and glycine (non glycosylated forms)
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
ATP hyrdolysis couple to energetically unfavorable rxns

48. What is a silent mutation
UGA - UAA and UAG
Glycine
Same AA - often base change in 3rd position of codon (tRNA wobble)
Dec DNA - dec lymphos leads to SCID

49. What apolipoprotiens are on VLDL
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
B-100 - CII and E

50. What is the RDE of glycogenolysis
Glycogen phosphorylase
Night blindness - dry skin
Schilling test
Von Gierke's - Pompe - Cori - McArdle