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Biochemistry

Instructions:

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 disease can cause pellagra
Nine
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Reads usual codon but inserts wrong AA
Ca/calmodulin in muscle to coordinate with muscle activity

2. Where are FADH2 electrons transferred to...
Comlex II
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)
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
Medial dorsal nucleus of thalamus - mamillary bodies

3. What does a defective Cl channel do
Dermatitis - enteritis - alopecia - adrenal insuff
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
1 ring

4. What does CATCH 22 stand for and What causes is...
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Glycogen synthase
Antioxidant - protects RBCs and membrances from free radical damage

5. What is the purpose of the HMP shunt
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Degredation of dietary TG in small intestine
Glucose -6 phosphate
B6

6. What are Heinz bodies
ADPKD
Oxidized hemoglobin precipiated within RBCs
FAP
Wobble

7. What ribosomes do eukaryotes have
40 - 60 - 80
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
GAA

8. How many nucTIDEs is a tRNA and What does the secondary sturcture form
Base + ribose
Exercise: inc NAD/NADH - inc ADP - inc Ca
Cartilage - hyaline - vitreous body - nucleus pulposus
75 to 90 - cloverleaf

9. Which type of chromatin is less condensed - transcriptionally active - sterically accesible
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Zero
Euchromatin
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis

10. What is the activated carrier for aldehyddes
CAG
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
TTP
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

11. Which tumor suppresors inhibit G1 to S progression - where mutations result in unrestrained growth
4 under the floor
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
No - its non homologous
Rb and p53

12. What does desmin stain for
Dec methionine - inc cystiene - inc B12/folate
Thymic - parathyroid and cardiac
30 - 50 - 70
Muscle

13. What are the purely ketogenic amino acids
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Leu - lys
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
Facial flushing

14. What do def in in enzymes of gluconeogenesis cause
Type II
Glycogen synthase
Alpha1 antitrypsin
Hypoglycemia

15. How is vit D stored
25OHD3
Seals.
HMG- CoA reductase
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

16. What activates the pyruvate dehydrogenase complex
Blood - bone marrown - amniotic fluid - placental tissue
Exercise: inc NAD/NADH - inc ADP - inc Ca
Malonyl coa
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

17. What is the Name and fxn of vit B5
Myeloperoxidase
Night blindness - dry skin
Promotor - TATA box - and CAAT box - AT rich
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase

18. What apolipoprotiens are on VLDL
Ile - phe - thr - trp
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
RRNA
B-100 - CII and E

19. What is the breakdown product of epi
Nissl body - enzyme and NTs
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Alpha 1 -4 glucosidase
Metanephrine

20. What is incomplete penetrence and give an example
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Not all individuals with a mutant genotype show the mutant phenotype
Phenylketones in urine

21. How does abetalipoproteinemia present and What is the defect
Phenylalanine
Schilling test
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
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

22. What do B- complex vitamin deficiencies often result in
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
Muscle
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Dermatitis - glossitis - and diarrhea

23. what gene is implicated in fragile X syndrome - and What is the mutation
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
HMG- CoA (HMG- CoA to mevalonate
FMR1 gene - methylation - associated with chromosomal breakage
Orotic acid to UMP

24. cytoskeletal elements associated with cilia - flagella - mitotic spindle - neurones and centrioles
Cytosol - F 1 -6 BP to fructose 6 Phosphate
AR
Microtubules
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR

25. What makes up a nucleoside
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Base + ribose
Ile - phe - thr - trp
Mebendazole/thiabendazole

26. What rxn does propionyl - CoA carboxylase catalyze
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
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Keep glutathione reduced so it can detoxify free radicals and peroxides
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

27. What does the primary transcript combine with to form the spliceosome
SnRNPs and other proteins
Kidney - ears - eyes
Males are infertile due to bilateral absence of vas deferens
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

28. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Targets the proteins for lysosome
4 under the floor
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

29. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
CTG
Liver - also in kidney and gut epithelium
Glucose -6 phosphate

30. How do tetracyclines work
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Phenylalanine
TTP

31. What are the mRNA stop codons
UGA - UAA and UAG
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Failure to track objects or develop a social smile
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

32. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Avidin
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Pseudomonas and s aureus

33. What is the TX for PKU
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Euchromatin
Pyruvate - NAD+ - CoA
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

34. What are the priorities for the body in fasting and starvation
Glycogen synthase
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Supply sufficient glucose to brain and RBCs and to preserve protein
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine

35. What does apoE do
32 - malate aspartate shuttle
Mediates extra remnant take up
Makes RNA primer on which DNA poly III can initiate replication
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels

36. What are the results of CF on male fertility
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
Males are infertile due to bilateral absence of vas deferens
Tyrosine
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR

37. Type IV collagen is an important structural componenet of the BM for which 3 organs
Kidney - ears - eyes
NAD+
Silencers
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR

38. What is disulfiram used for
Pyruvate - NAD+ - CoA
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Ile - phe - thr - trp

39. What is the energy source in the fed state right after a meal
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
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Glycolysis and aerobic respiration
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)

40. What are the complications/signs of familial hypercholesterolemia
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
2 rings
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine

41. What enzyme def can cause emphysema
Alpha1 antitrypsin
Infection - free radicals generated by inflammatory response
One
Abnormal protein folding - degradation before reaching cell surface

42. Which amino acids are elastin rich in
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Proline and glycine (non glycosylated forms)
Glutamate

43. trinucleotide repeat for huntingtons
Liver - ovaries - seminal vesicles
CAG
Degradation of TG stored in adipocytes
Creat a nick in the helix to relieave supercoils created during replication

44. In a marathon Where does energy come from
Adenosine to inosine
Biotin
Alkaptonuria - may have debiliating arthralgias
Glycogen and FFA oxidation; glucose conserved for final sprinting

45. What happens in vit B2 def
Facial flushing
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Prevent strands from reannealing
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

46. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Fibrofatty replacement of muscle - cardiac myopathy
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
MEN - 2A and 2B with ret gene
Inc CPK and muscle biopsy

47. What are the reactants for glycolysis
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Degredation of TG circulating in chylomicrons and VLDLs
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Glucose - 2Pi - 2ADP - 2NAD+

48. colon becomes covered witih adenomatous polyps after puberty - progresses to colon cancer unless resected
Von Gierke's - Pompe - Cori - McArdle
Hereditary spherocytosis
FAP
Glucose 6 phosphate dehydrogenase (G6PD)

49. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
Cri du chat
PCR - denaturation - annealing - elongation
Von gierkes - glucose 6 phosphatase
Base + ribose

50. What is proteasomal degredation
After citruline
4 under the floor
Attachment of ubiquitin to defective proteins tag them for breakdown
Cri du chat