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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. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
F16BP
Oxidative and nonoxidative - no ATP produced or used
Oxidative is irreversible
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

2. What can excess vit B3 cause
Facial flushing
Leu - lys
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Superoxide dismutase

3. What are the results of pancreatic insuff in CF
After citruline
B48 - AIV - CII - E
Glycine
Malabsorption and steatorrhea (ADEK)

4. What are the glucogenic/ketogenic amino acids
TRNA
MEN - 2A and 2B with ret gene
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Ile - phe - thr - trp

5. What happens at the smooth ER
Site of steroid synthesis and detoxification of drugs and poisons
NADPH
Peroxide
UDP glucose pyrophosphorylase

6. What ribosomes do prokaryotes have
Base + ribose
30 - 50 - 70
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Binds to LDL receptor - mediates VLDL secretion

7. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
NF2 on chromosome 22
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Cre - lox system
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -

8. What happens to oxaloacetate in alcholism
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Dopa decarboxylase
In ER - glucose 6- P to glucose
Fibrofatty replacement of muscle - cardiac myopathy

9. What does CATCH 22 stand for and What causes is...
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Acetoacetate and beta hydroxybutyrate

10. What is the defect in II A familial hypercholesterolemia
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
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Males are infertile due to bilateral absence of vas deferens

11. What does pancreatic lipase do
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
Change resulting in early stop codon
Degredation of dietary TG in small intestine
Degradation of TG stored in adipocytes

12. What is the amino acid precursor for catecholamines
Glycine - aspartate - glutamine
Phenylalanine
Arginine
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

13. What are the blood glucose levels maintained by for days 1-3
NADH - NADPH - FADH2
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)
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Inc CPK and muscle biopsy

14. Is there any requirement for homology in NHEJ
Leu - lys
Carbomoyl phosphate synthetase II
No - its non homologous
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

15. What CETP do
PCR - denaturation - annealing - elongation
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

16. Which anti breast cancer drugs work on micortubules
Acetyl - CoA
Malonyl coa
DTMP
Paclitaxel

17. What is the activated carrier for Acyl
G6PD
Change resulting in early stop codon
Fructose 1 -6 bisphosphate
Coenzyme A - lipoamide

18. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Muscle
PCR - denaturation - annealing - elongation
Change resulting in early stop codon

19. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Intermediate filaments
Cri du chat
Removal of N or C termal propeptides from zymogens to generate mature proteins

20. What does the primary transcript combine with to form the spliceosome
5' to 3'
Comlex II
Conversion of NE to epi
SnRNPs and other proteins

21. Broadly - What can cause fat - soluble vitamin deficiencies
Lariat shape in order and remove intron precisely and join 2 exons
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
Malapsorption syndromes like sprue or CF or mineral oil intake

22. What does a carboxylase do
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
Adds 2 carbon with the help of biotin
Mediates extra remnant take up
NF2 on chromosome 22

23. Synthesis of vit B3 requires what other vitamin
Not all individuals with a mutant genotype show the mutant phenotype
Bind 30s subunit preventing attachment of aminoacyl - tRNA
After citruline
B6

24. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
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
DsRNA promotes degradation of target mRNA knocking down gene expression
Alpha - ketoglutarate dehydrogenase complex

25. What enzyme converts adenine to AMP
Acetyl - CoA to malonyl - CoA (2C to 3C)
APRT + PRPP
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Q -

26. What is the amino acid precuror for creatine - urea and nitric oxide
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Consesus sequenec of base pairs
Achondroplasia
Arginine

27. What happens in vit B2 def
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Dec methionine - inc cystiene - inc B12/folate
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
Alanine

28. What chromosome is the NF gene on...
Antioxidant - protects RBCs and membrances from free radical damage
MEN - 2A and 2B with ret gene
17 - 17 letters in von Recklinghausen
Liver - ovaries - seminal vesicles

29. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Oxidized hemoglobin precipiated within RBCs
Prevent strands from reannealing
LDL
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

30. What stretch of DNA that alters gene expression by binding of transcription factors
Arginine
Enhancers
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
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

31. Which bond is stronger AT or CG and why? What is the laboratory consequence of this?
Conversion of NE to epi
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
CG- 3 > AT-2 - More CG content - melting point goes up

32. What does vit C def cause
Type II
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Lysine and arginine

33. What are the symptoms of vit A excess
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Griseofulvin
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

34. Do balanced translocations cause abnl phenotype
No
Neg to pos
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
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

35. congenital microdeletion of long arm of chromosoe 7 with findings of elfin facies - mental retardation - hypercalcemia - well developed verbal skills - extreme friendliness with strangers - cardiovascular problems
Williams syndrome
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
THFs
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms

36. What does GFAP stain for
Neuralgia
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Neither of 2 alleles is dominant - blood groups

37. Type I bone
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Proton gradient
BOne
Euchromatin

38. What is the hardy weinber heterozygote prevalence
Unmethylated - newly synthesized - HNPCC
2pq
Alkaptonuria - may have debiliating arthralgias
Sulfation

39. recurrent pulmonary infxns in CF are due to what organisms
Glucose - 2Pi - 2ADP - 2NAD+
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Pseudomonas and s aureus
Alpha 1 -6 and alpha 1 -4

40. How many ATP are produced by anearobic glycolysis per molecule of glucose
Two
Avidin
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes

41. What is the rate limiting enzyme in cholesterol synthesis
Accelearted muscle breakdown
HMG- CoA (HMG- CoA to mevalonate
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Breaks down acyl - coa to acetyl coa groups in mito

42. What does a phosphorylase do
Alpha 1 -6 and alpha 1 -4
Inhibits 50S peptidyltransferase
Adds an inorganic phosphate onto substrate without using ATP
SAM

43. What reaction does adenosine deaminase normally catalyze
HDL
Adenosine to inosine
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
Actin and myosin

44. What enzyme def can cause emphysema
Diphyllobothrium latum
2 rings
Alpha1 antitrypsin
Creat a nick in the helix to relieave supercoils created during replication

45. What does hepatic TG lipase do
Abnormal protein folding - degradation before reaching cell surface
CGG
Cre - lox system
Degradation of TG remaining in IDL

46. What does a mischarge tRNA do
Reads usual codon but inserts wrong AA
Colchicine
Phenylketones in urine
Autosomal recessive diseases

47. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Wernicke - korsakoff - dry and wet beriberi
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Zero
Malapsorption syndromes like sprue or CF or mineral oil intake

48. Where is glucokinase found - What are the Km and Vmax - and what induces it
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Base + ribose + phosphate (3' -5') phosphodiester bond
Schilling test

49. What substance inside the cell serves to oxidize glutatione
Peroxide
Lactate
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
Polyneuritis - symmetrical muscle wasting

50. How does abetalipoproteinemia present and What is the defect
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
LCAT (lecithin cholesterol acyltransferase)
Changed AA (convservative - new AA is similar in chemical structure)
Same as sprint + OXPHOS