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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. How is ammonium transported from muscle to the liver for urea cycle
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Night blindness - dry skin
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle
SNP

2. Give an example of a mitochondrial inherited disease
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Type II
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

3. What happens in a B12 def
Tryptophan
Peroxide
75 to 90 - cloverleaf
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

4. Describe the structure of cilia
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
2pq
9+2 arrangement of microtubules
Not all individuals with a mutant genotype show the mutant phenotype

5. What is the structure of elastin
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
Cytosol
Tropoelastin with fibrillin scafolding
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)

6. Where is glucokinase found - What are the Km and Vmax - and what induces it
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
P2 +2pq+ = 1
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

7. What does the vimentin stain for
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Connective tissue
RRNA
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

8. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Kidney - ears - eyes
X linked frame shif mutation
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)
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side

9. What is axonemal dynein
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Liver - also in kidney and gut epithelium
Ribos first then deoxyribos with ribonucleotide reductase

10. In what cells do the respiratory burst occur
PMNs
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Disease
Abnormal protein folding - degradation before reaching cell surface

11. what findings are associated with marfans
Coenzyme A - lipoamide
Transfers methyl units
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
F16BP

12. central and peripheral demyelination with ataxia and dementia
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
Tryptophan
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Carbomoyl phosphate synthetase I

13. How does patients present with ADPKD
EtOH dehydrogenase and acetaldehyde dehydrogenase
Flank pain - hematuria - HTN - progressive renal failure
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
SnRNPs

14. How is orotic aciduria inherited
Tryptophan
Carbomoyl phosphate synthetase II
AR
Anabolic processes as a supply of reducing equivalents

15. A small proportion of Down syndrome is due to What two genetic events
Robertsonian translocation and mosaicism
1 kind with multiple subunits
32 - malate aspartate shuttle
RNA

16. energy malnutrition resulting in tissues and muscle wasting - loss of subQ fat - variable edema
2pq
B6
Marasmus - muscle wasting
Deamination

17. What enzyme results in classic galactosemia and What is the clinical
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
X- linked recessive
Wobble
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

18. Describe the pathophys of the aorta in a pt with marfans - and the eyes
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Williams syndrome
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

19. What is the Name and function of vit B2
Conversion of NE to epi
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Achondroplasia
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

20. What is the RDE of glycogen synthesis
Glycogen synthase
Males are infertile due to bilateral absence of vas deferens
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Mebendazole/thiabendazole

21. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Autosomal recessive diseases
Actin and myosin

22. What are the 3 AR forms of homocystinuria
Tuberous sclerosis
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Post to neg
AR

23. What ribosomes do eukaryotes have
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
40 - 60 - 80
Inc insulin - dec cAMP - dec PKA

24. 90% of ADPKD cases are due to a mutation In what gene
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
VLDL
APKD1 on chromosome 16
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty

25. What does hartnups disease cause
Peroxide
Site of steroid synthesis and detoxification of drugs and poisons
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Stored ATP - creatine phosphate - anaerobic glycolysis

26. What reaction does adenosine deaminase normally catalyze
Inc glucagon - inc cAMP - inc PKA
30 - 50 - 70
Adenosine to inosine
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele

27. What is the activated carrier for aldehyddes
CarTWOlage
III - joint dislocation - anuerysms - organ rupture
TTP
Diphyllobothrium latum

28. What are bite cells and when do you see them
Result from phagocytic removal of heinz bodies my macs - G6PD def
PFK - rate limiting enzyme
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Glycine

29. What is the complication of cystinuria
Each codon specifies only 1 amino acid
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
B6

30. What is kartageners syndrome
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Alpha and beta tubulin - dimers have two GTP bound
Debranching enzyme
Mediates chylomicron secretion

31. What is the treatment for orotic aciduria
Collagen
Oral uridine administration
Active secretion in lungs and GI - reabsorbs in skin
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

32. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
No
Eu - methionine - pro - formyl - methionine
Inc glucagon - inc cAMP - inc PKA
Huntingtons

33. Is there any requirement for homology in NHEJ
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
G6PD
No - its non homologous

34. characterize autosomal recessive inheritance
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
PMNs
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Males are infertile due to bilateral absence of vas deferens

35. What kind of branches do glycogen branches have
Alpha 1 -6 and alpha 1 -4
RRNA
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Von hippel lindau - 3

36. What is the purpose of the HMP shunt
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Thymic - parathyroid and cardiac
Ketone - methyl

37. What are pyrimidines made from
Orotate precursor - with PRPP added later
Sulfation
Phenylalanine hydroxylase
Asp and Glu

38. What is the RDE of de novo pyrimidine synthesis
30 - glycerol -3- phosphate shuttle
PMNs
Carbomoyl phosphate synthetase II
Leu - lys

39. What is the TX for PKU
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Locus heterogeneity - ocular albinism is x- linked recessive
Autosomal recessive diseases
B-100 - CII and E

40. 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
Attachment of ubiquitin to defective proteins tag them for breakdown
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Glycogenolysis to form glucose
Scrutinizes - hydrolyzes the bond

41. What are the only purely ketogenic amino acids
Lysine and leucine
ATP and methionine
Medial dorsal nucleus of thalamus - mamillary bodies
Base + ribose + phosphate (3' -5') phosphodiester bond

42. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
RER
Exercise: inc NAD/NADH - inc ADP - inc Ca
Oxidative and nonoxidative - no ATP produced or used
B48 - AIV - CII - E

43. What is disulfiram used for
AMP - fructose 2 -6 BP
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Lacks glucose 6 phophatase
4 under the floor

44. What is the fxn of vit K
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Tryptophan
Glycogen phosphorylase
LCAT (lecithin cholesterol acyltransferase)

45. Why can't even chain fatty acids produce new glucose
They yield only acetyl - CoA equivalents
O- oligosaccharaides
Nine
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis

46. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Unmethylated - newly synthesized - HNPCC
Assistance of upper extremities to stand up
Fibrofatty replacement of muscle - cardiac myopathy
Basement membrane or basal lamina

47. How does ouabain work
Alanine
Inhibits the Na/K pump by binding the K side
Coenzyme A - lipoamide
3' end (with CCA)

48. What apolipoprotiens are on VLDL
B-100 - CII and E
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Dec DNA - dec lymphos leads to SCID
Catabolic processes to carry reducing equivalents away as NADH

49. What does degenerate/rundant genetic code refer to...
More than 1 codon may code for the same amino acid
Dopa decarboxylase
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse

50. What metabolic rxns occur in both the cytoplasm and mitochondria
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
30 - 50 - 70
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

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