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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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1. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Inhibits 50S peptidyltransferase
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Heterochromatin = HighlyCondensed

2. What does lactase deficiency cause
Thymic - parathyroid and cardiac
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Alpha1 antitrypsin

3. What order kinetics does EtOH dehydrogenase have
Zero
Tuberous sclerosis
Q -
Isocitrate dehydrogenase

4. How many ATP are produced by anearobic glycolysis per molecule of glucose
Same AA - often base change in 3rd position of codon (tRNA wobble)
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
X- linked recessive
Two

5. In which state is FBPase -2 active
Rotenone - CN- - antimycin A - CO
Glycine - aspartate - glutamine
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Fasting

6. What is the activated carrier for Acyl
Coenzyme A - lipoamide
Alpha and beta tubulin - dimers have two GTP bound
IDL
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

7. What is the RDE of cholesterol synthesis
Purines= A - G pyrimidine = C - T (U)
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
HMG- CoA reductase
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

8. What does an umabiguous genetic code refer to...
Alpha 1 -4 glucosidase
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Each codon specifies only 1 amino acid

9. What is the defectin IV - hypertriglyceridemia
Alkaptonuria - may have debiliating arthralgias
Chylomicrons
Pyruvate to oxaloacetate (3C to 4C)
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL

10. What makes up a nucleoside
Base + ribose
CAG - 4
Alpha 1 -4 glucosidase
Changed AA (convservative - new AA is similar in chemical structure)

11. What is the activated carrier for methyl groups
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
SAM
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

12. What is mosaicism and give an example
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
B-100 - CII and E
Adds 2 carbon with the help of biotin
Neg to pos

13. What step of uric acid synthesis does xanthine oxidase catalyze
30 - glycerol -3- phosphate shuttle
Hypoxanthine to xanthing and xanthine to uric acid
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
DsRNA promotes degradation of target mRNA knocking down gene expression

14. What is NADPH's role inside RBCs
Stored ATP - creatine phosphate - anaerobic glycolysis
PCR - denaturation - annealing - elongation
Keep glutathione reduced so it can detoxify free radicals and peroxides
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

15. facial lesions - hypopigmented 'ash leaf spots -' cortical and retinal hamartomas - seizures - mental retardation - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas - inc risk of astrocytomas
Tuberous sclerosis
Vit K antagonist
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
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

16. What are the purely ketogenic amino acids
ATP - citrate
Leu - lys
Alpha - ketoglutarate dehydrogenase complex
Protein kinase A

17. What are the mRNA stop codons
BOne
Stored ATP - creatine phosphate - anaerobic glycolysis
Makes RNA primer on which DNA poly III can initiate replication
UGA - UAA and UAG

18. What is the energy source in the fed state right after a meal
Liver - also in kidney and gut epithelium
1 -25 OH2 D3 = calcitriol
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Glycolysis and aerobic respiration

19. The pyruvate dehydrogenase complex serves In what reaction: products
MRNA - tRNA
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Acetly- CoA - CO2 - NADH
PFK - rate limiting enzyme

20. Which direction does dynein go
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Post to neg
Karyotyping
Heterochromatin = HighlyCondensed

21. A small proportion of Down syndrome is due to What two genetic events
Robertsonian translocation and mosaicism
Wernicke - korsakoff - dry and wet beriberi
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

22. The pyruvate dehydorgenase complex serves In what reaction: reactants
Q -
Abnormal protein folding - degradation before reaching cell surface
Pyruvate - NAD+ - CoA
Base + ribose

23. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
Specific glycosylases - AP endonuclease
Enhancers
PCR - denaturation - annealing - elongation
Kwashiorkor - small child with swollen belly

24. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Cofactor for LPL
LDL
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

25. What is loss of heterozygosity and give an example
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
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma
ATP - citrate
Each codon specifies only 1 amino acid

26. 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
Two
Stored ATP - creatine phosphate - anaerobic glycolysis
FAP

27. In base excision repaire - what recognizes and removes damaged bases and what cuts the DNA to remove the empty sugar
Wernicke - korsakoff - dry and wet beriberi
Actin and myosin
Specific glycosylases - AP endonuclease
Read from a fixed starting point as a continuous sequence of bases

28. What does the golgi add to serine and threonine residues
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
ATP - citrate
Ribos first then deoxyribos with ribonucleotide reductase
O- oligosaccharaides

29. What is imprinting and give an example

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30. How do glucagon/epi lead to glycogenolysis
Same as sprint + OXPHOS
Niacin - constituent of NAD and NADP - derived from tryptophan
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Sucrose = glucose + fructose - lactose = glucose + galactose

31. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
Cre - lox system
DTMP
40 - 60 - 80
Post to neg

32. What causes biotin def
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
No
Antibiotic use or excessive ingestion of raw eggs
High output cardiac failure - dilated cardiomyopathy - edema

33. What is the RDE of glycogen synthesis
Catabolic processes to carry reducing equivalents away as NADH
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Glycogen synthase
Glycogen phosphorylase

34. What is NAD+ generally used for
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Catabolic processes to carry reducing equivalents away as NADH

35. What does the CFTR channel do in the lungs - GI tract and skin
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Active secretion in lungs and GI - reabsorbs in skin
Oral uridine administration
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels

36. What is the RDE of fatty acid oxidation
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Elastase - inhibited by alpha1 antitrypsin
Glucose 6 phosphate dehydrogenase (G6PD)
Carnitine acyltransferase I

37. How many rings do pyrimidines have
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Antibiotic use or excessive ingestion of raw eggs
Assistance of upper extremities to stand up
1 ring

38. What is variable expression and What is an example
Makes RNA primer on which DNA poly III can initiate replication
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility

39. What is the activated carrier for electrons
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
III - joint dislocation - anuerysms - organ rupture
NADH - NADPH - FADH2

40. Inhibition of thymidilate synthase and and DHFR lead to decrease In what substance
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Defect in fibrillin
Inc insulin - dec cAMP - dec PKA
DTMP

41. What are the water soluble vitamins - which ones are stored
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

42. What enzyme degrades a small amount of glycogen in lysosomes
Abnormal protein folding - degradation before reaching cell surface
Alpha 1 -4 glucosidase
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Consesus sequenec of base pairs

43. How do permanent cells grow and regenerate and What are examples of permanent cells
Consesus sequenec of base pairs
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
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
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

44. characterize x linked dominant
1 -25 OH2 D3 = calcitriol
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
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. What is codominance and give an example
Neither of 2 alleles is dominant - blood groups
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Microarrays

46. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Marfans
Phenylalanine hydroxylase
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
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

47. bilateral - massive enlargement of of kidneys due to multiple large cysts
Initiate chains
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
5' to 3'
ADPKD

48. Which phase of the HMP shunt is reversible and Which is irreversible
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Nonsense > missense > silent
Oxidative is irreversible

49. energy malnutrition resulting in tissues and muscle wasting - loss of subQ fat - variable edema
Creat a nick in the helix to relieave supercoils created during replication
Marasmus - muscle wasting
LCAT (lecithin cholesterol acyltransferase)
Infection - free radicals generated by inflammatory response

50. What does helicase do
RNA
Mucus secreting globlet cells and antibody secreting plasma cells
Hereditary spherocytosis
Unwinds DNA template at replcation fork