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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 does a northern blot use as its sample
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
RNA
Alpha 1 -4 glucosidase
MRNA - tRNA

2. What regulates whether FBPase -2 or PFK-2 is active
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Antioxidant - protects RBCs and membrances from free radical damage
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Protein kinase A

3. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Neurofibromatosis type 1 (von Recklinghausens disease)
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Oxalacetate

4. What are cyclin - CDK complexes
32 - malate aspartate shuttle
Alpha 1 -4 glucosidase
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Must be both activated and inactivated for cell cycle to progress

5. What bone disorder has x linked dominant inheritance
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Fibroblast
Phosphorylation - glycosylation - hydroxylation
Malabsorption and steatorrhea (ADEK)

6. Where is glucokinase found - What are the Km and Vmax - and what induces it
B100 and E
Arg and his inc in histones Which bind negatively charged DNA
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
AR

7. caf
UDP glucose pyrophosphorylase
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Abnormal protein folding - degradation before reaching cell surface
Neurofibromatosis type 1 (von Recklinghausens disease)

8. What does cytokeratin stain for
Abnormal protein folding - degradation before reaching cell surface
SnRNPs
Epithelial cells
Schilling test

9. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
Inhibit DNA gyrase specific for prokaryotic topoisomerase
RER
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Alkaptonuria - may have debiliating arthralgias

10. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Mutated dystrophin gene - less severe - adolescence
HMG- CoA synthase
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

11. What does SAM do
Palate - facial and cardiac defects
Transfers methyl units
LDL
Dec DNA - dec lymphos leads to SCID

12. What is the breakdown product of NE
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
VMA
No
Polycystic liver disease - berry aneurysm - mitral valve prolapse

13. What happens in folate def
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Inhibits 50S peptidyltransferase

14. What does a dehydrogenase do
O- oligosaccharaides
Oxidizes substrate
Facial flushing
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

15. What enzyme converts glucose 1 p to UDP glucose
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Cytosol
UDP glucose pyrophosphorylase

16. What does GFAP stain for
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Neuralgia
N to C
Base + ribose + phosphate (3' -5') phosphodiester bond

17. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Essential fructosuria - fructokinase AR
Chylomicrons
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
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

18. In what cell is collagen synthesis initiated
RRNA
FAP
DTMP
Fibroblast

19. What does the passage of electrons result in that when coupled to OXPHOS drives the production of ATP
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Proton gradient
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

20. What does glycosylation of pro alpha chian yield and What is the structure
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
Neural tube
Procollagen - triple helix of 3 alpha collagen chains
Hereditary spherocytosis

21. Give an example of a mitochondrial inherited disease
Infection - free radicals generated by inflammatory response
25OHD3
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

22. Which RNA poly opens DNA at promotor site
MRNA - tRNA
The triphosphate bond
RNA poly II
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

23. What are the names and sources of the two types of vit D found in nature
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Proline and glycine (non glycosylated forms)
Debranching enzyme
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

24. What is the treatment for orotic aciduria
LCAT (lecithin cholesterol acyltransferase)
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Oral uridine administration
Phosphorylation - glycosylation - hydroxylation

25. In which state is PFK-2 active
Lactate
Alpha and beta tubulin - dimers have two GTP bound
Inc glucagon - inc cAMP - inc PKA
Fed

26. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Disorder of aromatic amino acid metabolism
Proline and lysine - vit C
Terminal regions - tropocollagen
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

27. What are the 3 AR forms of homocystinuria
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Essential fructosuria - fructokinase AR
Malabsorption and steatorrhea (ADEK)
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

28. Where do you find elastin and What does it do
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Metanephrine
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Hypoxanthine to xanthing and xanthine to uric acid

29. What is the activated carrier for 1 carbon units
THFs
UDP glucose pyrophosphorylase
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

30. What are the functinos of vitamin A
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Glycine - aspartate - glutamine
Base + ribose + phosphate (3' -5') phosphodiester bond
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

31. What does a southern blot use as its sample
CG- 3 > AT-2 - More CG content - melting point goes up
DNA
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
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

32. What substance inside the cell reduces glutatione
B12 and folate
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
NADPH
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

33. What causes Edwards syndrome and What is it
Vit K antagonist
Enhancers
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
Exons

34. What rxn creates ATP
Dec DNA - dec lymphos leads to SCID
Glycogen phosphorylase
Krabbes - galactocerebrosidase - galactocerebroside - AR
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

35. What is the TX for hyper ammonemia
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Lysine and arginine
NADH - NADPH - FADH2

36. What is the defect in I- hyperchylomicronemia
Free ribosomes
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

37. What is the results of vit B1 def
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Orotic acid to UMP
Inhibits the Na/K pump by binding the K side

38. What happens in termination of proteins synthesis
HVA
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
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
Stop codon is recognized by release factor - and completed protein is released from ribosome

39. Type III collagen
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Nissl body - enzyme and NTs
Alpha 1 -4 glucosidase

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

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41. How many ATP are produced by anearobic glycolysis per molecule of glucose
N to C
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Two
After citruline

42. What causes B12 def
Myeloperoxidase
Lactate
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Assistance of upper extremities to stand up

43. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
30 - glycerol -3- phosphate shuttle
CAG - 4
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Microtubules

44. What does the mutation in the gene cause in protein synthesis
Alpha and beta tubulin - dimers have two GTP bound
Wrinkles and acne
Abnormal protein folding - degradation before reaching cell surface
Catabolic processes to carry reducing equivalents away as NADH

45. Which anti gout drugs work on microtubules
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Colchicine
Glycogenolysis to form glucose
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

46. What do neurofilaments stain for
Inhibits the Na/K pump by binding the K side
Mutated dystrophin gene - less severe - adolescence
III - joint dislocation - anuerysms - organ rupture
Neurons

47. What are cyclins
Failure to track objects or develop a social smile
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Citrate - acetyl coa from mito to cyto
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

48. Pts with albinism are at inc risk For what cancer
Skin
DNA
Lysine and arginine
Sucrose = glucose + fructose - lactose = glucose + galactose

49. What are pyrimidines made from
Base + ribose + phosphate (3' -5') phosphodiester bond
Orotate precursor - with PRPP added later
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Phenytoin - MTX - and sulfonamides

50. Why is G6PD def more common among patients of african decent
Protective against malaria
Initiate chains
Promotor - TATA box - and CAAT box - AT rich
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies