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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 pleiotropy and given an example
Cre - lox system
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Neuralgia
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

2. What metabolic rxns occur in the cytoplasm
Methionine encode by only 1 codon (AUG)
Silencers
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Flagella - cilia - mitotic spindles

3. What is RNAi used for
Alpha and beta tubulin - dimers have two GTP bound
DsRNA promotes degradation of target mRNA knocking down gene expression
UDP glucose pyrophosphorylase
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

4. What is kartageners syndrome
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
MEN - 2A and 2B with ret gene
Terminal regions - tropocollagen
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

5. What ribosomes do eukaryotes have
Acetyl - CoA
Essential fructosuria - fructokinase AR
40 - 60 - 80
Bind 30s subunit preventing attachment of aminoacyl - tRNA

6. CF - is AR deletion In what gene On what chromosome resulting in a deletion inf what?
EtOH dehydrogenase and acetaldehyde dehydrogenase
Acetyl - CoA carboxylase (ACC)
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
CFTR gene - 7 - Phe 508

7. What tissues have both enzymes of sorbitol metabolism
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Hypoxanthine to xanthing and xanthine to uric acid
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Liver - ovaries - seminal vesicles

8. In a marathon Where does energy come from
Night blindness - dry skin
Glycogen and FFA oxidation; glucose conserved for final sprinting
ATP
Inhibits 50S peptidyltransferase

9. What is the exception to genetic redundancy
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Glycogen phosphorylase
Methionine encode by only 1 codon (AUG)
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

10. What does primase do
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Stored ATP - creatine phosphate - anaerobic glycolysis
Makes RNA primer on which DNA poly III can initiate replication
Activates LCAT

11. What does a kinase do
Uses ATP to add high energy phophate group onto substrate
Lysine and arginine
1 kind with multiple subunits
G6PD

12. What are cyclins
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
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
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
HMP shunt

13. What is the defect in I- hyperchylomicronemia
Transmitted only through mother - all offspring of affected females may show signs of disease
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Hyperlipidemia
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

14. Name 5 drugs that interfere with nucleotide synthesis
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
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Phosphofructokinase 1
Superoxide dismutase

15. decreases In what substances can cause PKU
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
SAM
Carnitine acyltransferase I
MRNA

16. characterize autosomal domint inheritance
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Cleft palate - cardiac abnl - pregs test
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

17. What does DNA poly I do?
Inhibits the Na/K pump by binding the K side
Carbomoyl phosphate synthetase I
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Mcardle's - skeletal muscle glycogen posphorylase

18. Describe the location and fxn of the Na/K ATPase
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
N to C
Mutated dystrophin gene - less severe - adolescence
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side

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

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20. What happens in vit D def
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Comlex II
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)

21. in a 100 meter sprint Where does energy come from
Cleft palate - cardiac abnl - pregs test
Degradation of TG remaining in IDL
DNA
Stored ATP - creatine phosphate - anaerobic glycolysis

22. What causes Down syndrome
Glucose -6 phosphate
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Dopamine beta hydroxylase
HMP shunt

23. What defects characterize velocardiofacial syndrome
Reads usual codon but inserts wrong AA
Palate - facial and cardiac defects
AR
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

24. Where is glucokinase found - What are the Km and Vmax - and what induces it
Nissl body - enzyme and NTs
3' end (with CCA)
Microtubules
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

25. congenital microdeletion of long arm of chromosoe 7 with findings of elfin facies - mental retardation - hypercalcemia - well developed verbal skills - extreme friendliness with strangers - cardiovascular problems
Marasmus - muscle wasting
Oxidized hemoglobin precipiated within RBCs
Williams syndrome
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

26. delivers hepatic TGs to peripheral tissue - secreted by liver
VLDL
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

27. What co - factors are required for the pyruvated dehydrogenase complex
Protein kinase A
Vit K antagonist
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

28. What happens in termination of proteins synthesis
1 -25 OH2 D3 = calcitriol
Stop codon is recognized by release factor - and completed protein is released from ribosome
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Liver - also in kidney and gut epithelium

29. What enzyme converts glucose 1 p to UDP glucose
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Karyotyping
Phenylalanine hydroxylase
UDP glucose pyrophosphorylase

30. Which direction does kinesin go
Neg to pos
B-100 - CII and E
Glutamate
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR

31. What is loss of heterozygosity and give an example
1 kind with multiple subunits
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
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
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

32. What are the physical findings of fragile x syndrome
Isocitrate dehydrogenase
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
VLDL
Alkaptonuria - may have debiliating arthralgias

33. What is the activated carrier for electrons
NADH - NADPH - FADH2
Avidin
ATP and methionine
MRNA

34. What is the purpose of the HMP shunt
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Pyruvate - NAD+ - CoA
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE

35. What is the function of folic acid
Zero
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Free ribosomes

36. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
Only processed RNA
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

37. What is the prevalence of an X- linked recessive disease in males and in females
Glutamine PRPP amidotransferase
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Q -

38. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Each codon specifies only 1 amino acid
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Infection - free radicals generated by inflammatory response

39. What causes patau's syndrome and What is it
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Rotenone - CN- - antimycin A - CO
Mcardle's - skeletal muscle glycogen posphorylase
Exercise: inc NAD/NADH - inc ADP - inc Ca

40. What are the findings with homocystinuria and What amino acid is needs to be supplemented
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
THFs
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine

41. What are pyrimidines made from
Keep glutathione reduced so it can detoxify free radicals and peroxides
Orotate precursor - with PRPP added later
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Assistance of upper extremities to stand up

42. developmental delay - gargoylism - airway obstruction - corneal clouding - hepatosplenomegaly
III - joint dislocation - anuerysms - organ rupture
PMNs
Medial dorsal nucleus of thalamus - mamillary bodies
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR

43. What are purines made from
IMP precursor
Keep glutathione reduced so it can detoxify free radicals and peroxides
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Liver and leafy veggies

44. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Lysine and arginine
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Changed AA (convservative - new AA is similar in chemical structure)

45. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
LDL
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Leu - lys

46. Which are the basic amino acids
UGA - UAA and UAG
Arg - lys - his - arg is most basic - has has no charge at body pH
SNP
THFs

47. What does the mutation in the gene cause in protein synthesis
Glucose 6 phosphate dehydrogenase (G6PD)
III - joint dislocation - anuerysms - organ rupture
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Abnormal protein folding - degradation before reaching cell surface

48. What is the treatment for orotic aciduria
N to C
Glucose - 2Pi - 2ADP - 2NAD+
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Oral uridine administration

49. Describe robertsonian translocation
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Neural tube

50. What is Retin A used topically for
Tyrosine
HVA
Wrinkles and acne
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase