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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. Describe the structure of cilia
Creat a nick in the helix to relieave supercoils created during replication
Wrinkles and acne
9+2 arrangement of microtubules
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes

2. Very Poor Carbohydrate Metabolism stands for 4 of the glycogen storage diseases - What are thy

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3. Describe the location and fxn of the Na/K ATPase
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Changed AA (convservative - new AA is similar in chemical structure)
Antioxidant - protects RBCs and membrances from free radical damage
DsRNA promotes degradation of target mRNA knocking down gene expression

4. What does a mischarge tRNA do
Williams syndrome
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Reads usual codon but inserts wrong AA

5. What are Heinz bodies
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Oxidized hemoglobin precipiated within RBCs
ATP hyrdolysis couple to energetically unfavorable rxns
Attachment of ubiquitin to defective proteins tag them for breakdown

6. What are the findings in Lesch - Nyhan
17 - 17 letters in von Recklinghausen
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Carnitine acyltransferase I

7. What test is used for B12 def
Schilling test
O- oligosaccharaides
Degradation of TG remaining in IDL
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR

8. What is the trinucleotide repeat in fragile X
CGG
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Elastase - inhibited by alpha1 antitrypsin
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis

9. In eukaryotes - What does RNA poly I make
Each codon specifies only 1 amino acid
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
VMA
RRNA

10. A small proportion of Down syndrome is due to What two genetic events
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Sucrose = glucose + fructose - lactose = glucose + galactose
Robertsonian translocation and mosaicism
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

11. What 3 syndromes are associated with vit B1 def
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
4 under the floor
Lysine and leucine
Wernicke - korsakoff - dry and wet beriberi

12. In base excision repaire - what recognizes and removes damaged bases and what cuts the DNA to remove the empty sugar
L form
Specific glycosylases - AP endonuclease
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Vit K antagonist

13. What does pancreatic lipase do
Malapsorption syndromes like sprue or CF or mineral oil intake
VMA
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
Degredation of dietary TG in small intestine

14. What substance inside the cells replenishes NADPH
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
G6PD
Glutamate
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

15. What is the energy source after day 3 of starvation
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
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
MRNA - tRNA
Niacin - constituent of NAD and NADP - derived from tryptophan

16. What is the RDE of ketogenesis
HMG- CoA synthase
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)
Alanine
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

17. 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
40 - 60 - 80
Terminal regions - tropocollagen
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
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

18. In which direction is protein synthesized
N to C
Neurofibromatosis type 1 (von Recklinghausens disease)
Antibiotic use or excessive ingestion of raw eggs
Von hippel lindau - 3

19. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Oxalacetate
Wrinkles and acne
Inc dicarboxylic acids - dec in glucose and ketones
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

20. What enzyme does fructose metabolism bypass to reach glycolysis
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
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Glycogenolysis to form glucose
PFK - rate limiting enzyme

21. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
Acetyl - CoA
Orotate precursor - with PRPP added later
Only processed RNA
32 - malate aspartate shuttle

22. CF - is AR deletion In what gene On what chromosome resulting in a deletion inf what?
Medial dorsal nucleus of thalamus - mamillary bodies
Diphyllobothrium latum
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
CFTR gene - 7 - Phe 508

23. How do cardia glycosides work
Von hippel lindau - 3
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
ATP and methionine
RNA poly II

24. How does patients present with ADPKD
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Flank pain - hematuria - HTN - progressive renal failure
Four
Von gierkes - glucose 6 phosphatase

25. What are the 3 AR forms of homocystinuria
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Modifies N- oligosaccharides
Phosphofructokinase 1
Isocitrate dehydrogenase

26. What does a kinase do
Orotate precursor - with PRPP added later
N to C
CFTR gene - 7 - Phe 508
Uses ATP to add high energy phophate group onto substrate

27. What does a western blot use for its sample
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Protein
UDP glucose pyrophosphorylase
F16BP

28. What does the mutation in the gene cause in protein synthesis
Chylomicrons
Dec methionine - inc cystiene - inc B12/folate
Abnormal protein folding - degradation before reaching cell surface
Myeloperoxidase

29. What is proteasomal degredation
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Kidney - ears - eyes
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Attachment of ubiquitin to defective proteins tag them for breakdown

30. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Removal of N or C termal propeptides from zymogens to generate mature proteins
Inc insulin - dec cAMP - dec PKA
Oral uridine administration
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

31. hepatosplenomegaly - aseptic necrosis of femur - bone crisis - MACS that look like crumpled tissue paper

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32. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Removes phosphate group from substrate
X linked frame shif mutation
Fibroblast
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

33. cytoskeletal elements in micorvilli - muscle contracting fibers - cytokenesis - adherens jxns
Fructose 1 -6 bisphosphate
Targets the proteins for lysosome
Oxidative and nonoxidative - no ATP produced or used
Actin and myosin

34. Mediates reverse cholesterol transport from periphery to liver - acts as respository for apoC an apoE - secreted from both liver and small intestine
IMP precursor
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Malabsorption and steatorrhea (ADEK)
HDL

35. What causes Marfan syndrome
Defect in fibrillin
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Lactate
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

36. What does universal genetic code refer to and What are some exception
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Heterochromatin = HighlyCondensed
Y shaped region along the DNA template where leading nad lagging strands are synthesized
After citruline

37. What happens in elongation of protein synthesis

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38. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Glycine
Lysine and leucine
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

39. What is the Hardy Weinberg disease prevalence equation
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Oxidized hemoglobin precipiated within RBCs
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
P2 +2pq+ = 1

40. What happens in zinc def
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Activates LCAT
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
NAD+

41. What are cyclin - CDK complexes
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Must be both activated and inactivated for cell cycle to progress
Glycogen synthase
Adenosine to inosine

42. What does aminoacyl tRNA synthetase do the AA before and after it binds to tRNA - and what happens if it's the wrong the match
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Scrutinizes - hydrolyzes the bond

43. How does warfarin work
Oxidizes substrate
Acetly- CoA - CO2 - NADH
Vit K antagonist
Intermediate filaments

44. How do stable (quiescent) cells grow and regenerate and What are examples
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
No
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Arg - lys - his - arg is most basic - has has no charge at body pH

45. What is the activated carrier for Co2
Biotin
Peroxide
Euchromatin
Superoxide dismutase

46. cytoskeletal elements associated with cilia - flagella - mitotic spindle - neurones and centrioles
Stored ATP - creatine phosphate - anaerobic glycolysis
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Microtubules

47. Where is fructose 1 -6 bisphosphatase found and What does it do
Glycine - aspartate - glutamine
Cytosol - F 1 -6 BP to fructose 6 Phosphate
ATP and methionine
Basement membrane or basal lamina

48. How is vit D stored
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
25OHD3
Arginine
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting

49. What is the rate limiting enzyme in cholesterol synthesis
HMG- CoA (HMG- CoA to mevalonate
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

50. What do the single stranded binding proteins 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
APKD1 on chromosome 16
Prevent strands from reannealing
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond