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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. In which state is FBPase -2 active
Adipse tissue stores - keton bodies become the main source of energy fo the brain and heart - after these are depleted - vital protein degradation accelerates - leading to organ failure and death
Fasting
FAP
Lysine and leucine

2. What does the golgi assemble proteoglycans from
Core proteins
Autosomal recessive diseases
Each codon specifies only 1 amino acid
Acetly- CoA - CO2 - NADH

3. What does inc phenylalanine lead to...
Alcohol version of glucose - can trap glucose in cell - aldose reductase
After day 1
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Phenylketones in urine

4. What two pathways is carbomoyl phosphate involved in - and what enzyme deficiency leads to a build of carbamoyl phosphate leading to what element in pyrimidine 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
Inc glucagon - inc cAMP - inc PKA
No
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway

5. deletion of VHL gene on chromosome 3 leading to hemangioblastomas of retina/cerebellum/medulla bilateral RCC - dz and overexpression product
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Acetyl - CoA
Von hippel lindau - 3

6. What converts limit dextran to glucose
Mediates chylomicron secretion
ATP and alanine
Debranching enzyme
Vincritsine/vinblastine

7. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
1 -25 OH2 D3 = calcitriol
Orotic acid to UMP
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Heterochromatin = HighlyCondensed

8. What is the RDE of gluconeogenesis
Fructose 1 -6 bisphosphate
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway
Reads usual codon but inserts wrong AA
Von gierkes - glucose 6 phosphatase

9. What is the energy source for tRNA actication (charging)
Facial flushing
GTP
ATP
Removal of N or C termal propeptides from zymogens to generate mature proteins

10. What are the names and sources of the two types of vit D found in nature
Removes phosphate group from substrate
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Polycystic liver disease - berry aneurysm - mitral valve prolapse
HMG- CoA (HMG- CoA to mevalonate

11. Which phase of the HMP shunt is reversible and Which is irreversible
Oxidative is irreversible
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
RRNA
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

12. The pyruvate dehydrogenase complex serves In what reaction: products
5' to 3'
Oral uridine administration
FAP
Acetly- CoA - CO2 - NADH

13. How do stable (quiescent) cells grow and regenerate and What are examples
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Liver hepatocytes and steroid producing cells of the adrenal cortex
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Degredation of dietary TG in small intestine

14. How do tetracyclines work
Males are infertile due to bilateral absence of vas deferens
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Defect in fibrillin

15. What shuttle is involved in fatty acid synthesis and What does it move From where to where
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Euchromatin
Citrate - acetyl coa from mito to cyto
Karyotyping

16. What does DNA poly I do?
3' end (with CCA)
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
The triphosphate bond

17. What is the target of the 3' hydroxyl attack
The triphosphate bond
B-100 - CII and E
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
75 to 90 - cloverleaf

18. Which aspect of the spliceosome do patients with lupus make antibodies against
Stored ATP - creatine phosphate - anaerobic glycolysis
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Consesus sequenec of base pairs
SnRNPs

19. What is the most abundant protein in the body
Neg to pos
Collagen
Pseudomonas and s aureus
Adds an inorganic phosphate onto substrate without using ATP

20. Where is glucose 6 phosphatase found and What does it do
Cofactor for LPL
Palate - facial and cardiac defects
In ER - glucose 6- P to glucose
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase

21. What enzyme def can cause emphysema
Alpha1 antitrypsin
Accelearted muscle breakdown
Inc vit B6
Lysine and arginine

22. What is the fxn of vit K
Adds an inorganic phosphate onto substrate without using ATP
Dec methionine - inc cystiene - inc B12/folate
Fed
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora

23. What is the activated carrier for Acyl
Coenzyme A - lipoamide
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
IMP precursor

24. How does ethanol induce hypoglycemia
RNA poly II
More than 1 codon may code for the same amino acid
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
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

25. central and peripheral demyelination with ataxia and dementia
Oxidized hemoglobin precipiated within RBCs
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

26. facial lesions - hypopigmented 'ash leaf spots -' cortical and retinal hamartomas - seizures - mental retardation - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas - inc risk of astrocytomas
Infection - free radicals generated by inflammatory response
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Tuberous sclerosis
EtOH dehydrogenase and acetaldehyde dehydrogenase

27. What is pleiotropy and given an example
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Four

28. What makes up a nucleoside
G6PD
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Base + ribose
Grows slowly - collapses quickly

29. characterize mitochondrial inheritance
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
DNA
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
Transmitted only through mother - all offspring of affected females may show signs of disease

30. What enzyme results in classic galactosemia and What is the clinical
9+2 arrangement of microtubules
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

31. How do aminoglycosides work
By inhibiting formation of the initiation complex and cause misreading of mRNA
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
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
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis

32. What is the result of vit B5 def
Dermatitis - enteritis - alopecia - adrenal insuff
Protein kinase A
Mucus secreting globlet cells and antibody secreting plasma cells
PMNs

33. What produces NADPH
Grows slowly - collapses quickly
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Inhibit DNA gyrase specific for prokaryotic topoisomerase
HMP shunt

34. What induces pyruvate kinase
Arg - lys - his - arg is most basic - has has no charge at body pH
Nissl body - enzyme and NTs
F16BP
CG- 3 > AT-2 - More CG content - melting point goes up

35. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Locus heterogeneity - ocular albinism is x- linked recessive
Alpha - ketoglutarate dehydrogenase complex
Lacks glucose 6 phophatase

36. recurrent pulmonary infxns in CF are due to what organisms
Oxidative and nonoxidative - no ATP produced or used
They yield only acetyl - CoA equivalents
Superoxide dismutase
Pseudomonas and s aureus

37. How do labile celss grow and regenerate and What are examples
Liver and leafy veggies
ATP - citrate
LCAT (lecithin cholesterol acyltransferase)
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles

38. in a 100 meter sprint Where does energy come from
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
Stored ATP - creatine phosphate - anaerobic glycolysis
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

39. What does lipoprotein lipase do
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Degredation of TG circulating in chylomicrons and VLDLs
Night blindness - dry skin
PMNs

40. What enzyme adds Cl - to the H202 to makes bleach
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Binds to LDL receptor - mediates VLDL secretion
Myeloperoxidase
CAG

41. What are the glucogenic/ketogenic amino acids
Phenylalanine hydroxylase
Ile - phe - thr - trp
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
TRNA

42. What catacholamine step is SAM required for
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Ile - phe - thr - trp
Met - val - arg his
Conversion of NE to epi

43. Where is vit A found in the diet
Four
Liver and leafy veggies
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Tyrosine

44. What initiates protein synthesis
IMP precursor
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
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

45. Which antihelminthe drugs work on microtubules
One
Fibroblast
Mebendazole/thiabendazole
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side

46. What is the energy source after day 3 of starvation
Oligomycin
RRNA
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Adipse tissue stores - keton bodies become the main source of energy fo the brain and heart - after these are depleted - vital protein degradation accelerates - leading to organ failure and death

47. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Mutated dystrophin gene - less severe - adolescence
No - its non homologous
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

48. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
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
Heterochromatin = HighlyCondensed
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

49. What causes Marfan syndrome
ATP hyrdolysis couple to energetically unfavorable rxns
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
40 - 60 - 80
Defect in fibrillin

50. What does a dehydrogenase do
Fibrofatty replacement of muscle - cardiac myopathy
Type II
Oxidizes substrate
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene