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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 tetracyclines work
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Bind 30s subunit preventing attachment of aminoacyl - tRNA
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes

2. What drugs can cause folate def
Intermediate filaments
Marfans
Phenytoin - MTX - and sulfonamides
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -

3. What defects characterize DiGeorge syndrome
Thymic - parathyroid and cardiac
Dermatitis - enteritis - alopecia - adrenal insuff
Leu - lys
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis

4. What are the characteristics of angelmans syndrome and How does it occur
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
Assistance of upper extremities to stand up
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis

5. Leysh - Nyhan syndrome is a defect in which enzyme and What are the biochemical results
HGPRT - defective purine salvage - excess uric acid production
Basement membrane or basal lamina
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
32 - malate aspartate shuttle

6. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Robertsonian translocation and mosaicism
Sucrose = glucose + fructose - lactose = glucose + galactose
Read from a fixed starting point as a continuous sequence of bases

7. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Cre - lox system
Ribose 5- P to PRPP
Collagen
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints

8. What rxn does propionyl - CoA carboxylase catalyze
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Degradation of TG stored in adipocytes
Promotor - TATA box - and CAAT box - AT rich
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

9. What is the breakdown product of dopamine
HVA
Must be both activated and inactivated for cell cycle to progress
Degradation of TG remaining in IDL
Alcohol version of glucose - can trap glucose in cell - aldose reductase

10. Type IV BM
9+2 arrangement of microtubules
High output cardiac failure - dilated cardiomyopathy - edema
4 under the floor
DTMP

11. Which kind of osteogenesis imperfecta is fata in utero or in neonatal period
Removal of N or C termal propeptides from zymogens to generate mature proteins
Type II
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
After citruline

12. In what cells do the respiratory burst occur
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
APRT + PRPP
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
PMNs

13. What enzyme does fructose metabolism bypass to reach glycolysis
Core proteins
PFK - rate limiting enzyme
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
Alcohol version of glucose - can trap glucose in cell - aldose reductase

14. What catacholamine step is SAM required for
Arg - lys - his - arg is most basic - has has no charge at body pH
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Glycogen and FFA oxidation; glucose conserved for final sprinting
Conversion of NE to epi

15. Where is PEP carboxykinase found - What does it do - and What does it require
Uses ATP to add high energy phophate group onto substrate
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Tyrosine
Inc vit B6

16. in a 100 meter sprint Where does energy come from
FMR1 gene - methylation - associated with chromosomal breakage
Met - val - arg his
Stored ATP - creatine phosphate - anaerobic glycolysis
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

17. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Conversion of NE to epi
Degredation of dietary TG in small intestine
Sulfation
Terminal regions - tropocollagen

18. What is dominant negative mutation and give an example
Failure to track objects or develop a social smile
Inhibits the Na/K pump by binding the K side
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
Locus heterogeneity - ocular albinism is x- linked recessive

19. What does DNA ligase do
Seals.
X linked frame shif mutation
Ca/calmodulin in muscle to coordinate with muscle activity
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

20. What does the addition of mannose -6 phosphate do
Rb and p53
Targets the proteins for lysosome
Chylomicrons
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR

21. several distinct syndromes characterized by familial tumors of endocrine glands including pancreas - parathyroid - pituitary - thryoid and adrenal medulla - disorders and gene association
No - its non homologous
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
MEN - 2A and 2B with ret gene
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

22. Which end of the tRNA is the amino acid bound to...

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23. What are pyrimidines made from
Oxidizes substrate
RNA
Orotate precursor - with PRPP added later
CGG

24. What metabolic rxns occur in the mitochondria
Cre - lox system
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Degradation of TG remaining in IDL
Mediates chylomicron secretion

25. In which state is PFK-2 active
CAG
Base + ribose + phosphate (3' -5') phosphodiester bond
Fed
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

26. Which phase of the HMP shunt is reversible and Which is irreversible
Oxidative is irreversible
Stop codon is recognized by release factor - and completed protein is released from ribosome
One
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

27. What is the fxn of vit D
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Marfans
Liver - ovaries - seminal vesicles

28. What are the physical findings of fragile x syndrome
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
They yield only acetyl - CoA equivalents
ATP - citrate
Degredation of dietary TG in small intestine

29. What are Heinz bodies
Oxidized hemoglobin precipiated within RBCs
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Debranching enzyme
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

30. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
17 - 17 letters in von Recklinghausen
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

31. What happens in zinc def
Dermatitis - alopecia - enteritis
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
DsRNA promotes degradation of target mRNA knocking down gene expression
MEN - 2A and 2B with ret gene

32. Which direction does kinesin go
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Neg to pos
III - joint dislocation - anuerysms - organ rupture

33. What is sorbitol - how and why is it made
Rotenone - CN- - antimycin A - CO
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
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Keep glutathione reduced so it can detoxify free radicals and peroxides

34. Where are cytosolic and organellar proteins made
Oxidizes substrate
Met - val - arg his
Free ribosomes
Same AA - often base change in 3rd position of codon (tRNA wobble)

35. What happens in folate def
Proline and glycine (non glycosylated forms)
CarTWOlage
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase

36. What else can phosphoylate phosphorylase kinase
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Comlex II
III - joint dislocation - anuerysms - organ rupture
Ca/calmodulin in muscle to coordinate with muscle activity

37. What is the rate limiting enzyme in cholesterol synthesis
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Phenylethamolamine N methyl transferase
HMG- CoA (HMG- CoA to mevalonate
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

38. Which are the basic amino acids
Arg - lys - his - arg is most basic - has has no charge at body pH
Glycogen phosphorylase
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Phosphorylation - glycosylation - hydroxylation

39. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
HMG- CoA (HMG- CoA to mevalonate
Sucrose = glucose + fructose - lactose = glucose + galactose
III - joint dislocation - anuerysms - organ rupture
Degradation of TG remaining in IDL

40. What does osteogenesis imperfecta causes and why
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin
Tropoelastin with fibrillin scafolding
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting

41. What two cells are particularly rich in RER
MEN - 2A and 2B with ret gene
Mucus secreting globlet cells and antibody secreting plasma cells
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
HMP shunt

42. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
Removes phosphate group from substrate
HMG- CoA synthase
Rotenone - CN- - antimycin A - CO
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

43. What is the fxn of vit K
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Fasting
Breaks down acyl - coa to acetyl coa groups in mito
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora

44. What apolipoprotiens are on VLDL
Proline and lysine - vit C
B-100 - CII and E
Oxidizes substrate
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)

45. What is the activated carrier for electrons
NADH - NADPH - FADH2
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
VMA

46. bilateral acoustic schwannomas - juvenile cataracts
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
NF2 on chromosome 22
Wrinkles and acne
Breaks down acyl - coa to acetyl coa groups in mito

47. What chromosome is the NF gene on...
17 - 17 letters in von Recklinghausen
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Dermatitis - alopecia - enteritis
Catabolic processes to carry reducing equivalents away as NADH

48. What is the RDE of gluconeogenesis
Coenzyme A - lipoamide
Fructose 1 -6 bisphosphate
Seals.
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

49. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Read from a fixed starting point as a continuous sequence of bases
IDL
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

50. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Avidin
Von gierkes - glucose 6 phosphatase
Lacks glucose 6 phophatase
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact