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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. Where are cytosolic and organellar proteins made
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Free ribosomes
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

2. What happens do glycogen in skeletal muscle during exercise
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
Abnormal protein folding - degradation before reaching cell surface
Liver - also in kidney and gut epithelium
Glycogenolysis to form glucose

3. What test is used for B12 def
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
Unwinds DNA template at replcation fork
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Schilling test

4. What is the rate limiting enzyme in cholesterol synthesis
Alpha - ketoglutarate dehydrogenase complex
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
HMG- CoA (HMG- CoA to mevalonate

5. What happens in the first stage of collagen synthesis - and Where does it happen
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Acetoacetate and beta hydroxybutyrate
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

6. What is locus heterogeneity and give an example
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

7. What is the Name and function of vit B1
Acetoacetate and beta hydroxybutyrate
More than 1 codon may code for the same amino acid
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Williams syndrome

8. What do neurofilaments stain for
Lysine and leucine
Transmitted only through mother - all offspring of affected females may show signs of disease
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Neurons

9. What is the breakdown product of epi
RRNA
Degradation of TG stored in adipocytes
Terminal regions - tropocollagen
Metanephrine

10. What substance inside the cell serves to oxidize glutatione
Mebendazole/thiabendazole
Schilling test
Peroxide
Change resulting in early stop codon

11. What is the initial transcript called and What is the capped and tailed transcript called
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Collagen
Covalent cross - linking by lysyl oxidase to make collagen fibrils

12. How does cytosine become uracil
Pseudomonas and s aureus
Deamination
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Phosphorylation - glycosylation - hydroxylation

13. What fxn does glucokinase serve in the liver
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
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
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

14. What causes Down syndrome
2pq
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Each codon specifies only 1 amino acid

15. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
Alpha 1 -4 glucosidase
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Karyotyping
Ketone - methyl

16. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Degradation of TG remaining in IDL
EtOH dehydrogenase and acetaldehyde dehydrogenase

17. What is the Hardy Weinberg disease prevalence equation
Oxidative is irreversible
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
P2 +2pq+ = 1

18. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
P2 +2pq+ = 1
Pseudomonas and s aureus
Alanine
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

19. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Vit K antagonist
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
LDL

20. What collagen type is most frequently affected in ehlers danlos and What are common complications
Males are infertile due to bilateral absence of vas deferens
No - its non homologous
Exercise: inc NAD/NADH - inc ADP - inc Ca
III - joint dislocation - anuerysms - organ rupture

21. Where do you find elastin and What does it do
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Stored ATP - creatine phosphate - anaerobic glycolysis
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Hypoglycemia

22. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Familial hypercholesterolemia - hyperlipidemia type IIA
Promotor - TATA box - and CAAT box - AT rich
Acetyl - CoA carboxylase (ACC)
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

23. What are the fetal screening measures for Down
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Vincritsine/vinblastine
Prevent strands from reannealing
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis

24. nucleotide repeat for fredreich's ataxia
GAA
Acetly- CoA - CO2 - NADH
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Antioxidant - protects RBCs and membrances from free radical damage

25. What causes B12 def
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Oxalacetate
Reads usual codon but inserts wrong AA
Pyruvate to oxaloacetate (3C to 4C)

26. What does arsenic do and What are th results of poisoning
Active secretion in lungs and GI - reabsorbs in skin
Terminal regions - tropocollagen
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

27. What is the physiologic role of dystrophin
ATP - citrate
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O

28. What is the RDE of glycogen synthesis
Glycogen synthase
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
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
1 kind with multiple subunits

29. What is the treatment for orotic aciduria
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Oral uridine administration
CarTWOlage

30. caf
Fructose 1 -6 bisphosphate
Neurofibromatosis type 1 (von Recklinghausens disease)
UGA - UAA and UAG
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

31. What happens in vit K def
Supply sufficient glucose to brain and RBCs and to preserve protein
FAP
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

32. Describe robertsonian translocation
Neuralgia
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
VLDL
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

33. facial lesions - hypopigmented 'ash leaf spots -' cortical and retinal hamartomas - seizures - mental retardation - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas - inc risk of astrocytomas
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Tuberous sclerosis
Same as sprint + OXPHOS
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

34. Giving folate during early pregnancy is important to prevent what birth defects
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Neural tube
Cartilage - hyaline - vitreous body - nucleus pulposus
Polyneuritis - symmetrical muscle wasting

35. Which anti gout drugs work on microtubules
Vincritsine/vinblastine
Anabolic processes as a supply of reducing equivalents
Colchicine
CGG

36. What makes up a nucleoside
Assistance of upper extremities to stand up
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Proline and lysine - vit C
Base + ribose

37. What is the most common urea cycle disorder and What is the mode of inheritance?
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Result from phagocytic removal of heinz bodies my macs - G6PD def

38. Which part of the DNA binds RNA polymerase and multiple other TFs upstream from gene locus
G6PD
Promotor - TATA box - and CAAT box - AT rich
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Purines= A - G pyrimidine = C - T (U)

39. What causes Hartnup's disease
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Oxidizes substrate
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Oligomycin

40. in a 100 meter sprint Where does energy come from
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Stored ATP - creatine phosphate - anaerobic glycolysis
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
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

41. What is the amino acid precursor for porphyrin and heme
Glycine
Elastase - inhibited by alpha1 antitrypsin
Removes phosphate group from substrate
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs

42. Where is EtOH dehydrogenase located
Cytosol
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Neurons
Colchicine

43. What enzyme def can cause emphysema
Alpha1 antitrypsin
RER
Accelearted muscle breakdown
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

44. Give an example of a mitochondrial inherited disease
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Glycogen phosphorylase
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

45. What rxn does propionyl - CoA carboxylase catalyze
Epithelial cells
P2 +2pq+ = 1
Debranching enzyme
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)

46. What is the RDE of fatty acid oxidation
Breaks down acyl - coa to acetyl coa groups in mito
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Carnitine acyltransferase I

47. What produces NADPH
HMP shunt
Consesus sequenec of base pairs
Familial hypercholesterolemia - hyperlipidemia type IIA
Covalent cross - linking by lysyl oxidase to make collagen fibrils

48. Where is vit B12 found
Inc insulin - dec cAMP - dec PKA
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Paclitaxel

49. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
B12 and folate
Nissl body - enzyme and NTs
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Semiconservative - continuous and discontinuous strands (okazaki fragments)

50. What enzyme turns ROS to H2O2
II - VII - IX - X (1972) protein C and S
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Superoxide dismutase