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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. What happens in vit D def
By inhibiting formation of the initiation complex and cause misreading of mRNA
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Lysine and leucine

2. What does the addition of mannose -6 phosphate do
Antibiotic use or excessive ingestion of raw eggs
Targets the proteins for lysosome
Inc melt - dec fluidity
LDL

3. What are the glucogenic/ketogenic amino acids
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Elastase - inhibited by alpha1 antitrypsin
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Ile - phe - thr - trp

4. What does GFAP stain for
Exons
Fasting
Acetly- CoA - CO2 - NADH
Neuralgia

5. What is the defect in fructose intolerance and What does it cause
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Phenylketones in urine
Mediates extra remnant take up
DTMP

6. What enzyme converts adenine to AMP
Polyneuritis - symmetrical muscle wasting
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
APRT + PRPP

7. What is the amino acid precursor for porphyrin and heme
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Glycine
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Prevent strands from reannealing

8. What rxn creates ATP
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
1 ring
Fed

9. What does PURe As Gold and CUT The Py stand for
Purines= A - G pyrimidine = C - T (U)
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
RNA poly II
TTP

10. What metabolic rxns occur in the mitochondria
Nine
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

11. What is the purpose of the HMP shunt
Read from a fixed starting point as a continuous sequence of bases
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Conversion of NE to epi
APKD1 on chromosome 16

12. What drugs can cause folate def
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Acetyl - CoA
Peroxide
Phenytoin - MTX - and sulfonamides

13. Give an example of a mitochondrial inherited disease
Isocitrate dehydrogenase
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Adenosine to inosine

14. What catacholamine step is SAM required for
Conversion of NE to epi
RER
Neuralgia
17 - 17 letters in von Recklinghausen

15. trinucleotide repeat for huntingtons
CAG
Modifies N- oligosaccharides
Failure to track objects or develop a social smile
Liver - ovaries - seminal vesicles

16. What is the function and name of vit B6
Unmethylated - newly synthesized - HNPCC
Pyroxidine - converted to pyroxidine phosphate a cofactor used in transamination - decarboxylation - glycogen phosphorylase - cystathionine synthesis and heme synthesis - required for synthesis of niacin and tryptophan
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

17. How many rings do pyrimidines have
Muscle
Thymic - parathyroid and cardiac
1 ring
II - VII - IX - X (1972) protein C and S

18. Patients with chronic granulomatous disease are at increased risk of infection From which kind of organisms
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
3' end (with CCA)
BOne
Pyroxidine - converted to pyroxidine phosphate a cofactor used in transamination - decarboxylation - glycogen phosphorylase - cystathionine synthesis and heme synthesis - required for synthesis of niacin and tryptophan

19. What are the characteristics of prader willi syndrome How does it occur
Lactate
RER
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Neuralgia

20. 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
ATP
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
30 - 50 - 70

21. What does apoE do
F16BP
Arginine
Mediates extra remnant take up
Glucose 6 phosphate dehydrogenase (G6PD)

22. What is the function of biotin
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

23. What ribosomes do prokaryotes have
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
30 - 50 - 70
Fibroblast
Epithelial cells

24. Where is vit B12 found
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Histidine
GTP
Fructose 1 -6 bisphosphate

25. Describe robertsonian translocation
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Exercise: inc NAD/NADH - inc ADP - inc Ca
Inc glucagon - inc cAMP - inc PKA
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

26. What does desmin stain for
Dermatitis - enteritis - alopecia - adrenal insuff
Muscle
APC on chromosome 5
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

27. RNA poly can't proofread - but What can it do
Proton gradient
IMP precursor
Initiate chains
Antibiotic use or excessive ingestion of raw eggs

28. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
RER
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Purines= A - G pyrimidine = C - T (U)
CG- 3 > AT-2 - More CG content - melting point goes up

29. How does chloramphenicol work
SAM
Inhibits 50S peptidyltransferase
Lysine and arginine
Degredation of dietary TG in small intestine

30. In eukaryotes - What does RNA poly II make
IDL
RER
MRNA
Malapsorption syndromes like sprue or CF or mineral oil intake

31. What are cyclins
Not all individuals with a mutant genotype show the mutant phenotype
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Zero
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond

32. What does apoA 1 do
Activates LCAT
Phenylketones in urine
P2 +2pq+ = 1
Tuberous sclerosis

33. what gene is implicated in fragile X syndrome - and What is the mutation
Inc CPK and muscle biopsy
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
HMG- CoA synthase
FMR1 gene - methylation - associated with chromosomal breakage

34. In what cells do the respiratory burst occur
Von Gierke's - Pompe - Cori - McArdle
PMNs
Alpha - ketoglutarate dehydrogenase complex
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

35. What two amino acids are required druing periods of growth and why
IMP precursor
Arg and his inc in histones Which bind negatively charged DNA
1 -25 OH2 D3 = calcitriol
EtOH dehydrogenase and acetaldehyde dehydrogenase

36. What is the activated carrier for aldehyddes
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
TTP
Pseudomonas and s aureus
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR

37. What part of the pre mRNA contains the actual genetic information coding for protein
Exons
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
BOne
CAG - 4

38. What is the treatment for cystathionine synthase def
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Dec methionine - inc cystiene - inc B12/folate
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

39. The pyruvate dehydorgenase complex serves In what reaction: reactants
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Kidney - ears - eyes
Pyruvate - NAD+ - CoA
Oxidized hemoglobin precipiated within RBCs

40. What happens to oxaloacetate in alcholism
Glutamate
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Protective against malaria
Bind 30s subunit preventing attachment of aminoacyl - tRNA

41. What are ketone bodies made from - where are they metabolized and how are they excreted
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Polyneuritis - symmetrical muscle wasting
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Defect in fibrillin

42. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Inc melt - dec fluidity
Proton gradient
DTMP
Phenylalanine

43. 1 g of protein or cabrohydrate = ?kcal
Four
5' to 3'
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Conversion of NE to epi

44. What is the RDE of de novo purine synthesis
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
Neither of 2 alleles is dominant - blood groups
UDP glucose pyrophosphorylase
Glutamine PRPP amidotransferase

45. What makes up a nucleoside
Actin and myosin
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
Base + ribose
B100

46. What is the result of vit B5 def
Dermatitis - enteritis - alopecia - adrenal insuff
Paclitaxel
HVA
Dermatitis - glossitis - and diarrhea

47. What does vit C def cause
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Arg and his inc in histones Which bind negatively charged DNA

48. What 3 amino acids are necessary for purine synthesis
5' of the incoming nucleotide
Glycine - aspartate - glutamine
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Zero

49. What is pleiotropy and given an example
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Peroxide
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Hypoglycemia

50. Why enzyme breaks down elastin and what enzyme inhibits it
Base + ribose + phosphate (3' -5') phosphodiester bond
Elastase - inhibited by alpha1 antitrypsin
Leu - lys
Phenytoin - MTX - and sulfonamides