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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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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. How does warfarin work
Vit K antagonist
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

2. trinucleotide repeat fo myotonic dystrophy
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
CTG
Niacin - constituent of NAD and NADP - derived from tryptophan
ATP

3. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Fasting
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
IDL
Alcohol version of glucose - can trap glucose in cell - aldose reductase

4. How does insulin inhibit glycogenolysis
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Uses ATP to add high energy phophate group onto substrate
Oxidizes substrate
Von hippel lindau - 3

5. What does the mutation in the gene cause in protein synthesis
Abnormal protein folding - degradation before reaching cell surface
No
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
CAG

6. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
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
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate

7. What 3 steps in RNA processing occur after transcription

8. RNA poly can't proofread - but What can it do
HMG- CoA reductase
Initiate chains
HVA
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons

9. What co - factors are required for the pyruvated dehydrogenase complex
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Superoxide dismutase
Eu - methionine - pro - formyl - methionine
RER

10. What does desmin stain for
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Adds an inorganic phosphate onto substrate without using ATP
Muscle
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

11. What is a frame shift
Unmethylated - newly synthesized - HNPCC
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Eu - methionine - pro - formyl - methionine
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

12. delivers hepatic TGs to peripheral tissue - secreted by liver
VLDL
Ile - phe - thr - trp
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms

13. What does Ehlers Danlos cause and why
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Inhibits RNA polymerase II - found in death cap mushrooms
Deamination
Y shaped region along the DNA template where leading nad lagging strands are synthesized

14. What step of uric acid synthesis does xanthine oxidase catalyze
F16BP
1 ring
Assistance of upper extremities to stand up
Hypoxanthine to xanthing and xanthine to uric acid

15. What do def in in enzymes of gluconeogenesis cause
Inhibits the Na/K pump by binding the K side
Carbomoyl phosphate synthetase II
Read from a fixed starting point as a continuous sequence of bases
Hypoglycemia

16. What is the complication of cystinuria
Uses ATP to add high energy phophate group onto substrate
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Asp and Glu
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

17. What are the results of pancreatic insuff in CF
Wernicke - korsakoff - dry and wet beriberi
Malabsorption and steatorrhea (ADEK)
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Stored ATP - creatine phosphate - anaerobic glycolysis

18. What enzymes metabolize fatty acids and amino acids
Skin
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Acetoacetate and beta hydroxybutyrate

19. What is the mutation in beckers muscular dystrophy - What is the severity and time of onset
Avidin
Mutated dystrophin gene - less severe - adolescence
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

20. What is the RDE of gluconeogenesis
3' end (with CCA)
Mutated dystrophin gene - less severe - adolescence
Protective against malaria
Fructose 1 -6 bisphosphate

21. What is the function of folic acid
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Post to neg
CGG
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

22. What is the most abundant type of RNA
RRNA
Disorder of aromatic amino acid metabolism
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
HMG- CoA (HMG- CoA to mevalonate

23. What liberates glucose from glucose 6 P
Prevent strands from reannealing
Glucose 6 phosphatase
Glycogen synthase
Arg and his inc in histones Which bind negatively charged DNA

24. caf
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Neurofibromatosis type 1 (von Recklinghausens disease)
32 - malate aspartate shuttle
Griseofulvin

25. What enzyme converts glucose 1 p to UDP glucose
UDP glucose pyrophosphorylase
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Binds 50S - blocking translocation

26. What are the fetal screening measures for Down
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Exons
Abnormal protein folding - degradation before reaching cell surface
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

27. FAP is due to deletion On what gene On what chromosome
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
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
APC on chromosome 5
Familial hypercholesterolemia - hyperlipidemia type IIA

28. What is the activated carrier for aldehyddes
TTP
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Nonsense > missense > silent

29. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
After citruline
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
Makes RNA primer on which DNA poly III can initiate replication

30. Which direction does kinesin go
Creat a nick in the helix to relieave supercoils created during replication
Neg to pos
Dermatitis - enteritis - alopecia - adrenal insuff
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

31. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
Arg - lys - his - arg is most basic - has has no charge at body pH
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Hereditary spherocytosis
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

32. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Liver - ovaries - seminal vesicles
Kwashiorkor - small child with swollen belly
Inc melt - dec fluidity
Bruton's agammaglobulinemia - wiskott - aldrich - fabrys disease - G6PD def - ocular albinism - Lesch - Nyhan syndrome - Duchenne and Becker Muscular Dystrophy - hunter's syndrome - hemophilia A and B

33. What is locus heterogeneity and give an example
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Abnormal protein folding - degradation before reaching cell surface
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

34. What neuroanatomical strutures are injured in wernicke - korsakoff
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year
Medial dorsal nucleus of thalamus - mamillary bodies
2 rings

35. Type I collagen
Disorder of aromatic amino acid metabolism
Oligomycin
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
ATP

36. What is the origin of replication
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
P+q = 1
Particular sequence of DNA where replicatino begins - may be single of multiple
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)

37. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
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

38. What happens in folate def
Arg - lys - his - arg is most basic - has has no charge at body pH
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
ADPKD

39. How does chloramphenicol work
Alanine
CG- 3 > AT-2 - More CG content - melting point goes up
Inhibits 50S peptidyltransferase
1 -25 OH2 D3 = calcitriol

40. What does the golgi apparatus do on asparagine
Modifies N- oligosaccharides
Wrinkles and acne
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Huntingtons

41. Why is G6PD def more common among patients of african decent
Euchromatin
Protective against malaria
Night blindness - dry skin
Type II

42. What is the treatment for dec affinity of cystathionine synthase for pyroxidal phosphate
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Inc vit B6
Wernicke - korsakoff - dry and wet beriberi
DTMP

43. What shuttle is used in fatty acid degredation and What does it move and From where to where
Carnitine shuttle - acyl - coa from cyto to mito
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Rotenone - CN- - antimycin A - CO
EtOH dehydrogenase and acetaldehyde dehydrogenase

44. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Schwann cells - lens - retina - kidneys

45. What ribosomes do prokaryotes have
Wernicke - korsakoff - dry and wet beriberi
Nine
30 - 50 - 70
Schwann cells - lens - retina - kidneys

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

47. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
After citruline
Infection - free radicals generated by inflammatory response
Diphyllobothrium latum
The triphosphate bond

48. What enzyme converts adenine to AMP
B48 - AIV - CII - E
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
APRT + PRPP
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

49. How does abetalipoproteinemia present and What is the defect
CarTWOlage
Acetyl - CoA carboxylase (ACC)
Post to neg
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

50. Which amino acids are elastin rich in
Proline and glycine (non glycosylated forms)
Mebendazole/thiabendazole
Wobble
UGA - UAA and UAG