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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 drugs can cause folate def
Phenytoin - MTX - and sulfonamides
Wernicke - korsakoff - dry and wet beriberi
Y shaped region along the DNA template where leading nad lagging strands are synthesized
RRNA

2. What substances directly inhibit electron transport chain
Rotenone - CN- - antimycin A - CO
Peroxide
Read from a fixed starting point as a continuous sequence of bases
Glycolysis and aerobic respiration

3. What kind of RNA is transported out of the nucleus
Dec methionine - inc cystiene - inc B12/folate
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Only processed RNA
Lysine and leucine

4. What two cells are particularly rich in RER
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
Liver hepatocytes and steroid producing cells of the adrenal cortex
Supply sufficient glucose to brain and RBCs and to preserve protein
Mucus secreting globlet cells and antibody secreting plasma cells

5. What are the fat soluble vitamins and What does their absorption depend on...
Mediates chylomicron secretion
Euchromatin
Glutamate
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

6. What is NAD+ generally used for
Catabolic processes to carry reducing equivalents away as NADH
Vincritsine/vinblastine
Liver - ovaries - seminal vesicles
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

7. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Ribose 5- P to PRPP
Niacin - constituent of NAD and NADP - derived from tryptophan
Lariat shape in order and remove intron precisely and join 2 exons
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

8. What does fomepizole do
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Acetly- CoA - CO2 - NADH
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O

9. delivers hepatic TGs to peripheral tissue - secreted by liver
Biotin
African Americans and Asians
VLDL
Fasting

10. The pyruvate dehydorgenase complex serves In what reaction: reactants
Zero
Consesus sequenec of base pairs
Pyruvate - NAD+ - CoA
ATP

11. Which antihelminthe drugs work on microtubules
Mebendazole/thiabendazole
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Carnitine acyltransferase I
EtOH dehydrogenase and acetaldehyde dehydrogenase

12. What are the names and sources of the two types of vit D found in nature
Anchor muscle fibers - primarily in skeletal and cardiac muscle
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Inc melt - dec fluidity
Facial flushing

13. What apolipoproteins are on IDL
Kidney - ears - eyes
Modifies N- oligosaccharides
B100 and E
CGG

14. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
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
Pseudomonas and s aureus
Binds 50S - blocking translocation
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

15. What is variable expression and What is an example
Seals.
CAG - 4
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR

16. What is the target of the 3' hydroxyl attack
The triphosphate bond
Exercise: inc NAD/NADH - inc ADP - inc Ca
Phosphofructokinase 1
Marasmus - muscle wasting

17. Where is vit B12 found
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Eu - methionine - pro - formyl - methionine
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver

18. What shuttle is involved in fatty acid synthesis and What does it move From where to where
Flagella - cilia - mitotic spindles
Reads usual codon but inserts wrong AA
Citrate - acetyl coa from mito to cyto
Von gierkes - glucose 6 phosphatase

19. I g fat = ? Kcal
Nine
VLDL
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Proline and glycine (non glycosylated forms)

20. What are possilbe presentation for galactokinase def
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
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
Failure to track objects or develop a social smile

21. What 3 amino acids are necessary for purine synthesis
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Glycine - aspartate - glutamine

22. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
RNA poly II
Alpha1 antitrypsin
UGA - UAA and UAG
Familial hypercholesterolemia - hyperlipidemia type IIA

23. Which tumor suppresors inhibit G1 to S progression - where mutations result in unrestrained growth
Rb and p53
Acetoacetate and beta hydroxybutyrate
SnRNPs and other proteins
Transmitted only through mother - all offspring of affected females may show signs of disease

24. Describe the location and fxn of the Na/K ATPase
Colchicine
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Malapsorption syndromes like sprue or CF or mineral oil intake

25. Who typically has lactase def
Hepatic glycogenolysis - adipose tissue release of FFA - muslce and liver FFA - hepatic gluconeogenesis from peripheral tissue lactate and alanine and from adipose tissue glycerol and proprionyl - coA (odd chain FFA)
African Americans and Asians
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

26. What is maternal PKU
Orotate precursor - with PRPP added later
ATP - citrate
Catabolic processes to carry reducing equivalents away as NADH
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

27. What are the teratogenic effects of vit A and What test must be ordered before starting a woman on isotreitinoin for severe acne
Flagella - cilia - mitotic spindles
Glycolysis and aerobic respiration
B48 - AIV - CII - E
Cleft palate - cardiac abnl - pregs test

28. What is the mutation in beckers muscular dystrophy - What is the severity and time of onset
Mutated dystrophin gene - less severe - adolescence
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes

29. Which anti gout drugs work on microtubules
2 -4 DNP - aspirin
Vit K antagonist
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Colchicine

30. What substance inside the cell serves to oxidize glutatione
HMG- CoA synthase
The triphosphate bond
UDP glucose pyrophosphorylase
Peroxide

31. What does the golgi assemble proteoglycans from
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Pyruvate to oxaloacetate (3C to 4C)
Leu - lys
Core proteins

32. What are covalent alterations
Phosphorylation - glycosylation - hydroxylation
Cre - lox system
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
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

33. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
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
Avidin
1 kind with multiple subunits
Krabbes - galactocerebrosidase - galactocerebroside - AR

34. cytoskeletal elements associated with cilia - flagella - mitotic spindle - neurones and centrioles
Tyrosine
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Dermatitis - glossitis - and diarrhea
Microtubules

35. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Neuralgia
Inc glucagon - inc cAMP - inc PKA
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
FISH

36. What is the defect in II A familial hypercholesterolemia
Exons
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Oxidized hemoglobin precipiated within RBCs
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

37. What does inc phenylalanine lead to...
Liver - also in kidney and gut epithelium
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Phenylketones in urine

38. What test is used for B12 def
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Blood - bone marrown - amniotic fluid - placental tissue
Dec methionine - inc cystiene - inc B12/folate
Schilling test

39. What does hepatic TG lipase do
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Foliage - small reserve in liver - eat green leaves
Degradation of TG remaining in IDL

40. What chromosome is the NF gene on...
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
1 ring
Pyruvate to oxaloacetate (3C to 4C)
17 - 17 letters in von Recklinghausen

41. Name 5 drugs that interfere with nucleotide synthesis
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Transmitted only through mother - all offspring of affected females may show signs of disease
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome

42. What is the RDE of cholesterol synthesis
In ER - glucose 6- P to glucose
HMG- CoA reductase
Abnormal protein folding - degradation before reaching cell surface
2 -4 DNP - aspirin

43. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Orotate precursor - with PRPP added later
Mediates extra remnant take up
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis

44. What 3 syndromes are associated with vit B1 def
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Terminal regions - tropocollagen
Wernicke - korsakoff - dry and wet beriberi

45. How many rings do pyrimidines have
Degradation of TG stored in adipocytes
1 ring
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Adds 2 carbon with the help of biotin

46. What are the water soluble vitamins - which ones are stored
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Oral uridine administration
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

47. What is the Name and function of vit B2
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Inc vit B6
BOne

48. Where do you find elastin and What does it do
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
X linked frame shif mutation
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
APC on chromosome 5

49. What are the findings in orotic aciduria
Cofactor for LPL
Acetoacetate and beta hydroxybutyrate
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive

50. Why is G6PD def more common among patients of african decent
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Protective against malaria
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
30 - 50 - 70