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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 is the function of Zinc
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Alpha1 antitrypsin
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -

2. What substances inhibit phosphofructokinase -1
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Pyruvate to oxaloacetate (3C to 4C)
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
ATP - citrate

3. What is the activated carrier for methyl groups
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
SAM
Dermatitis - glossitis - and diarrhea

4. What converts dopamine to NE
Citrate - acetyl coa from mito to cyto
Dopamine beta hydroxylase
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
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

5. What tissues have both enzymes of sorbitol metabolism
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
Post to neg
Alanine
Liver - ovaries - seminal vesicles

6. Type IV BM
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Removes phosphate group from substrate
ADPKD
4 under the floor

7. Where is EtOH dehydrogenase located
Cytosol
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

8. What happens on the nonoxidative arm of the HMP shunt and What is the key enzyme and cofactor
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
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
Niacin - constituent of NAD and NADP - derived from tryptophan
Failure to track objects or develop a social smile

9. Where do you find elastin and What does it do
Fibroblast
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
CarTWOlage
Nature and severity of phenotype vary from 1 individual to another - NF type 1

10. What is sorbitol - how and why is it made
Von Gierke's - Pompe - Cori - McArdle
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
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

11. What is the RDE of de novo pyrimidine synthesis
Carbomoyl phosphate synthetase II
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
II - VII - IX - X (1972) protein C and S

12. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Mcardle's - skeletal muscle glycogen posphorylase
Krabbes - galactocerebrosidase - galactocerebroside - AR

13. What makes up a nucleotide

14. What is the most common urea cycle disorder and What is the mode of inheritance?
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

15. In mismatch repair - which strand is recognized and In what hereditary syndrome is this defective
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Nonsense > missense > silent
Unmethylated - newly synthesized - HNPCC
Accelearted muscle breakdown

16. What are the priorities for the body in fasting and starvation
Von hippel lindau - 3
Result from phagocytic removal of heinz bodies my macs - G6PD def
Supply sufficient glucose to brain and RBCs and to preserve protein
1 ring

17. The pyruvate dehydrogenase complex serves In what reaction: products
African Americans and Asians
Alpha 1 -6 and alpha 1 -4
Disorder of aromatic amino acid metabolism
Acetly- CoA - CO2 - NADH

18. What does NADPH oxidase deficiency result in and why
Oxidative and nonoxidative - no ATP produced or used
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
ATP
APRT + PRPP

19. What is the Hardy Weinberg disease prevalence equation
1 -25 OH2 D3 = calcitriol
P2 +2pq+ = 1
B100 and E
G6PD

20. characterize autosomal domint inheritance
APC on chromosome 5
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Marfans
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty

21. Gene imprinting implies that How many alleles are active at a single locus
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Phenylketones in urine
One
Antioxidant - facilitates iron absorption by keeping iron in the Fe2+ reduced state - necessary for hydroxylation of proline and lysine collagen bridges - necessary for dopamine beta hydroxylase which converts DA to NE

22. What does acetyl - CoA become before becoming palmitate
Silencers
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Procollagen - triple helix of 3 alpha collagen chains

23. What does a dehydrogenase do
Oxidizes substrate
Methionine encode by only 1 codon (AUG)
Bind 30s subunit preventing attachment of aminoacyl - tRNA
9+2 arrangement of microtubules

24. What ribosomes do prokaryotes have
Ribos first then deoxyribos with ribonucleotide reductase
30 - 50 - 70
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Diphyllobothrium latum

25. What does vit B3 def result in
Fibroblast
Cytosol
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Cartilage - hyaline - vitreous body - nucleus pulposus

26. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
APKD1 on chromosome 16
LCAT (lecithin cholesterol acyltransferase)
Glucose 6 phosphate dehydrogenase (G6PD)
Intermediate filaments

27. What is the TX for CF and What does it do
Dopa decarboxylase
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Proton gradient

28. What are the fetal screening measures for Down
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
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
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Pyruvate to oxaloacetate (3C to 4C)

29. What clotting factors require vit K
Proline and lysine - vit C
DsRNA promotes degradation of target mRNA knocking down gene expression
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
II - VII - IX - X (1972) protein C and S

30. What does lactase deficiency cause
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Robertsonian translocation and mosaicism
Covalent cross - linking by lysyl oxidase to make collagen fibrils

31. Where is PEP carboxykinase found - What does it do - and What does it require
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
IMP precursor
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

32. Which type of chromatin is less condensed - transcriptionally active - sterically accesible
BOne
Fasting
Euchromatin
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

33. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
Abnormal protein folding - degradation before reaching cell surface
RER
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Supply sufficient glucose to brain and RBCs and to preserve protein

34. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Inc melt - dec fluidity
Protective against malaria
Modifies N- oligosaccharides
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond

35. What collagen type is most frequently affected in ehlers danlos and What are common complications
III - joint dislocation - anuerysms - organ rupture
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Unwinds DNA template at replcation fork
Achondroplasia

36. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Carnitine acyltransferase I
LDL
Phosphorylation - glycosylation - hydroxylation
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

37. What does cytokeratin stain for
Epithelial cells
Reads usual codon but inserts wrong AA
Glycolysis and aerobic respiration
Free ribosomes

38. trinucleotide repeat for huntingtons
25OHD3
Connective tissue
Isocitrate dehydrogenase
CAG

39. What is RNAi used for
DsRNA promotes degradation of target mRNA knocking down gene expression
Enhancers
ATP
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

40. What makes up a nucleoside
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
Base + ribose
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Mediates chylomicron secretion

41. What is disulfiram used for
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
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Attachment of ubiquitin to defective proteins tag them for breakdown

42. Which antihelminthe drugs work on microtubules
ATP and methionine
Mebendazole/thiabendazole
Peroxide
Zero

43. What two cells are particularly rich in RER
Arginine
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
African Americans and Asians
Mucus secreting globlet cells and antibody secreting plasma cells

44. What are the physical findings of fragile x syndrome
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Histidine
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse

45. What is the RDE of fatty acid oxidation
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
Procollagen - triple helix of 3 alpha collagen chains
Carnitine acyltransferase I
Carbomoyl phosphate synthetase II

46. How do macrolides and clindamycin work
Binds 50S - blocking translocation
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

47. What substance inside the cell serves to oxidize glutatione
Adds 2 carbon with the help of biotin
RRNA
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Peroxide

48. Where is glucokinase found - What are the Km and Vmax - and what induces it
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
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
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR

49. metaphse chromosomes are stained - ordered and numbered according to morphology - size - arm length ratio - banding pattern
Karyotyping
Type II
Stored ATP - creatine phosphate - anaerobic glycolysis
Regulatory proteins that control cell cycle events; phase specific; activate CDKs

50. How do aminoglycosides work
Fibrofatty replacement of muscle - cardiac myopathy
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
By inhibiting formation of the initiation complex and cause misreading of mRNA
Carnitine acyltransferase I