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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 are the results of pancreatic insuff in CF
Schilling test
Malabsorption and steatorrhea (ADEK)
LDL
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

2. What does CATCH 22 stand for and What causes is...
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Mutated dystrophin gene - less severe - adolescence
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

3. What is NADPH used for
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Promotor - TATA box - and CAAT box - AT rich
Anabolic processes as a supply of reducing equivalents
HMP shunt

4. What initiates protein synthesis
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Covalent cross - linking by lysyl oxidase to make collagen fibrils
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

5. What is the limiting reagent in EtOH metabolism
AMP - fructose 2 -6 BP
NAD+
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

6. What substance inside the cells replenishes NADPH
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
G6PD

7. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
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
Orotic acid to UMP

8. What does hormone sensitive lipase do
Glucose -6 phosphate
Biotin
Degradation of TG stored in adipocytes
Makes RNA primer on which DNA poly III can initiate replication

9. What is the TX for hyper ammonemia
Superoxide dismutase
B100
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels

10. What does acetyl - CoA become before becoming palmitate
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Arg - lys - his - arg is most basic - has has no charge at body pH
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
CG- 3 > AT-2 - More CG content - melting point goes up

11. What is the amino acid precuros for niacin and serotonin/melatonin
Tryptophan
The triphosphate bond
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Kwashiorkor - small child with swollen belly

12. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
32 - malate aspartate shuttle
HMG- CoA reductase
Glycogen and FFA oxidation; glucose conserved for final sprinting
CTG

13. What catacholamine step is SAM required for
Conversion of NE to epi
Four
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR

14. What is the RDE of the urea cycle
VMA
Wernicke - korsakoff - dry and wet beriberi
Post to neg
Carbomoyl phosphate synthetase I

15. What are the fat soluble vitamins and What does their absorption depend on...
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
Makes RNA primer on which DNA poly III can initiate replication
Purines= A - G pyrimidine = C - T (U)
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

16. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Poly A polymerase - signal is AAUAA
Alanine
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Procollagen - triple helix of 3 alpha collagen chains

17. What does a western blot use for its sample
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
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
Protein
Keep glutathione reduced so it can detoxify free radicals and peroxides

18. What happens on the nonoxidative arm of the HMP shunt and What is the key enzyme and cofactor
They yield only acetyl - CoA equivalents
African Americans and Asians
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA

19. Which antihelminthe drugs work on microtubules
Four
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
DNA
Mebendazole/thiabendazole

20. What is the RDE of cholesterol synthesis
HMG- CoA reductase
III - joint dislocation - anuerysms - organ rupture
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Biotin

21. What happens in hyperammonemia
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
RNA

22. Where is PEP carboxykinase found - What does it do - and What does it require
SnRNPs and other proteins
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
UDP glucose pyrophosphorylase
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

23. What are the water soluble vitamins - which ones are stored
Alanine
Palate - facial and cardiac defects
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

24. What test is used for B12 def
Schilling test
Vit K antagonist
ATP
Initiate chains

25. What happens in vit B2 def
Glycogenolysis to form glucose
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
AMP - fructose 2 -6 BP

26. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Fibrofatty replacement of muscle - cardiac myopathy
Catabolic processes to carry reducing equivalents away as NADH
Lactate

27. What substance accumulates in galactokinase def and What is the clinical picture
Phosphofructokinase 1
Inc Cl - in sweat
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR

28. nucleotide repeat for fragile x
CGG
Keep glutathione reduced so it can detoxify free radicals and peroxides
3' end (with CCA)
Locus heterogeneity - ocular albinism is x- linked recessive

29. Which antifungal drugs work on microtubules
Griseofulvin
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
FISH
Marasmus - muscle wasting

30. What is the RDE of ketogenesis
HGPRT - defective purine salvage - excess uric acid production
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
HMG- CoA synthase
Type II

31. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
Cre - lox system
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Dec methionine - inc cystiene - inc B12/folate
Palate - facial and cardiac defects

32. How is ammonium transported from muscle to the liver for urea cycle
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
Vincritsine/vinblastine
Cre - lox system
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

33. How does ethanol induce hypoglycemia
NADH - NADPH - FADH2
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
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
Nonsense > missense > silent

34. decreases In what substances can cause PKU
Glycine - aspartate - glutamine
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
TTP
B48 - AIV - CII - E

35. What does NADPH oxidase deficiency result in and why
Ca/calmodulin in muscle to coordinate with muscle activity
Hereditary spherocytosis
Ribos first then deoxyribos with ribonucleotide reductase
Chronic granulomatous disease - no respiatory burst - no formatino of ROS

36. What does the ELISA test for
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Antioxidant - protects RBCs and membrances from free radical damage
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
ADPKD

37. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
Diphyllobothrium latum
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Exons
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15

38. cell signaling defect of fibroblast growth factor (FGF) receptor 3 - results in dwarfism - short limbs - head/trunk nl size - associated with advanced paternal age
Polyneuritis - symmetrical muscle wasting
Consesus sequenec of base pairs
Terminal regions - tropocollagen
Achondroplasia

39. What is the RDE of fatty acid oxidation
Euchromatin
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Carnitine acyltransferase I
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O

40. How do tetracyclines work
Active secretion in lungs and GI - reabsorbs in skin
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Semiconservative - continuous and discontinuous strands (okazaki fragments)
30 - glycerol -3- phosphate shuttle

41. What is locus heterogeneity and give an example
Oxidized hemoglobin precipiated within RBCs
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15

42. What is the composition of urea and where do each part derive from
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Read from a fixed starting point as a continuous sequence of bases
Essential fructosuria - fructokinase AR

43. What is the treatment for orotic aciduria
Oral uridine administration
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Liver - ovaries - seminal vesicles
Chronic granulomatous disease - no respiatory burst - no formatino of ROS

44. What are the function of vit C
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
ATP and alanine
Phenytoin - MTX - and sulfonamides
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

45. cytoskeletal elements in micorvilli - muscle contracting fibers - cytokenesis - adherens jxns
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Asp and Glu
Nissl body - enzyme and NTs
Actin and myosin

46. What does DNA ligase do
Seals.
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Carbomoyl phosphate synthetase II
DsRNA promotes degradation of target mRNA knocking down gene expression

47. CF - is AR deletion In what gene On what chromosome resulting in a deletion inf what?
CFTR gene - 7 - Phe 508
Procollagen - triple helix of 3 alpha collagen chains
Initiate chains
Keep glutathione reduced so it can detoxify free radicals and peroxides

48. What are the two transgenic strategies in mice
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Mitochondria
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

49. What enzyme converts glucose 1 p to UDP glucose
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Williams syndrome
Nature and severity of phenotype vary from 1 individual to another - NF type 1
UDP glucose pyrophosphorylase

50. What is the fxn of vit D
Uses ATP to add high energy phophate group onto substrate
Degradation of TG stored in adipocytes
Ribose 5- P to PRPP
Inc intestinal absorption fo calcium and phosphate - inc bone resorption