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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 do stable (quiescent) cells grow and regenerate and What are examples
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Niacin - constituent of NAD and NADP - derived from tryptophan
Thymic - parathyroid and cardiac
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

2. What occurs to oxaloacetate in starvation and DKA
Orotate precursor - with PRPP added later
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Rotenone - CN- - antimycin A - CO

3. What does fomepizole do
Dermatitis - enteritis - alopecia - adrenal insuff
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Read from a fixed starting point as a continuous sequence of bases
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

4. Why enzyme breaks down elastin and what enzyme inhibits it
Removal of N or C termal propeptides from zymogens to generate mature proteins
One
Elastase - inhibited by alpha1 antitrypsin
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex

5. What are possilbe presentation for galactokinase 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
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
Leu - lys
Failure to track objects or develop a social smile

6. trinucleotide repeat for huntingtons
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
The triphosphate bond
CAG
Ca/calmodulin in muscle to coordinate with muscle activity

7. How many rings do purines have
2 rings
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Liver - ovaries - seminal vesicles
Medial dorsal nucleus of thalamus - mamillary bodies

8. metaphse chromosomes are stained - ordered and numbered according to morphology - size - arm length ratio - banding pattern
Karyotyping
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
DsRNA promotes degradation of target mRNA knocking down gene expression
Inc insulin - dec cAMP - dec PKA

9. What is the RDE of glycogen synthesis
Purines= A - G pyrimidine = C - T (U)
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Glycogen synthase
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization

10. in a 100 meter sprint Where does energy come from
Stored ATP - creatine phosphate - anaerobic glycolysis
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Acetly- CoA - CO2 - NADH
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

11. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
HVA
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
Cre - lox system

12. What does lactase deficiency cause
Glycine - aspartate - glutamine
Phenylalanine
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
2 rings

13. What are the characteristics of prader willi syndrome How does it occur
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
N to C
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Ribos first then deoxyribos with ribonucleotide reductase

14. central and peripheral demyelination with ataxia and dementia
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
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Procollagen - triple helix of 3 alpha collagen chains
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

15. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
Blood - bone marrown - amniotic fluid - placental tissue
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
Orotic acid to UMP
DsRNA promotes degradation of target mRNA knocking down gene expression

16. What does a defective Cl channel do
Ribos first then deoxyribos with ribonucleotide reductase
Inc vit B6
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

17. What is the Name and function of vit B2
Inc dicarboxylic acids - dec in glucose and ketones
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Unmethylated - newly synthesized - HNPCC
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism

18. What enzyme converts adenine to AMP
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
FAP
APRT + PRPP

19. What is codominance and give an example
Infection - free radicals generated by inflammatory response
Transfers methyl units
Neither of 2 alleles is dominant - blood groups
Microarrays

20. What stretch of DNA that alters gene expression by binding of transcription factors
PCR - denaturation - annealing - elongation
Enhancers
Inhibits RNA polymerase II - found in death cap mushrooms
Binds to LDL receptor - mediates VLDL secretion

21. What is heteroplasmy
Glycine
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
1 ring

22. trinucleotide repeat fo myotonic dystrophy
Superoxide dismutase
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Orotic acid to UMP
CTG

23. For eukaryotes - Where does replication begin?
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Consesus sequenec of base pairs
Oral uridine administration
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

24. Give an example of a mitochondrial inherited disease
CFTR gene - 7 - Phe 508
SnRNPs and other proteins
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

25. What is the name is fxn of vit B3
Niacin - constituent of NAD and NADP - derived from tryptophan
Citrate - acetyl coa from mito to cyto
GAA
Exons

26. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
Dopa decarboxylase
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

27. Why can't even chain fatty acids produce new glucose
Attachment of ubiquitin to defective proteins tag them for breakdown
They yield only acetyl - CoA equivalents
O- oligosaccharaides
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

28. What do neurofilaments stain for
Neurons
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Dermatitis - alopecia - enteritis
HVA

29. What is the most abundant protein in the body
Cre - lox system
Oral uridine administration
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Collagen

30. What is the Name and fxn of vit B12
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Q -
Coenzyme A - lipoamide
Disease

31. What shuttle is involved in fatty acid synthesis and What does it move From where to where
Citrate - acetyl coa from mito to cyto
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Tryptophan
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

32. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Fasting
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
Fibrofatty replacement of muscle - cardiac myopathy

33. In mismatch repair - which strand is recognized and In what hereditary syndrome is this defective
Unmethylated - newly synthesized - HNPCC
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Protective against malaria
G6PD

34. What causes Marfan syndrome
Sucrose = glucose + fructose - lactose = glucose + galactose
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Defect in fibrillin
IDL

35. Mediates reverse cholesterol transport from periphery to liver - acts as respository for apoC an apoE - secreted from both liver and small intestine
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Neither of 2 alleles is dominant - blood groups
HDL
Tyrosine

36. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
Kidney - ears - eyes
Same AA - often base change in 3rd position of codon (tRNA wobble)
B48 - AIV - CII - E
Intermediate filaments

37. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Tryosine hydroxylase
Seals.
Terminal regions - tropocollagen
Protein

38. What substances inhibit phosphofructokinase -1
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Creat a nick in the helix to relieave supercoils created during replication
ATP - citrate
Particular sequence of DNA where replicatino begins - may be single of multiple

39. Why is G6PD def more common among patients of african decent
Protective against malaria
Tropoelastin with fibrillin scafolding
Transmitted only through mother - all offspring of affected females may show signs of disease
Cytosol

40. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
30 - 50 - 70
Accelearted muscle breakdown
Oxalacetate
HDL

41. What does desmin stain for
Muscle
Vit K antagonist
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Von hippel lindau - 3

42. What clotting factors require vit K
ADPKD
Liver - ovaries - seminal vesicles
II - VII - IX - X (1972) protein C and S
Liver - also in kidney and gut epithelium

43. In a marathon Where does energy come from
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
Base + ribose + phosphate (3' -5') phosphodiester bond
Glycogen and FFA oxidation; glucose conserved for final sprinting
Glycogen synthase

44. How does insulin inhibit glycogenolysis
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Collagen
1 -25 OH2 D3 = calcitriol
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

45. What two pathways is carbomoyl phosphate involved in - and what enzyme deficiency leads to a build of carbamoyl phosphate leading to what element in pyrimidine synthesis
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
Malonyl coa
SnRNPs
Acetoacetate and beta hydroxybutyrate

46. In which direction is protein synthesized
Stored ATP - creatine phosphate - anaerobic glycolysis
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
After day 1
N to C

47. Leysh - Nyhan syndrome is a defect in which enzyme and What are the biochemical results
HGPRT - defective purine salvage - excess uric acid production
2 -4 DNP - aspirin
DsRNA promotes degradation of target mRNA knocking down gene expression
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

48. What is the defectin IV - hypertriglyceridemia
Inhibits the Na/K pump by binding the K side
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

49. Describe robertsonian translocation
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Liver - also in kidney and gut epithelium
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

50. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Lariat shape in order and remove intron precisely and join 2 exons
Epithelial cells
Ribose 5- P to PRPP
Polycystic liver disease - berry aneurysm - mitral valve prolapse