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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 converts dopamine to NE
Autosomal recessive diseases
Dopamine beta hydroxylase
TTP
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels

2. What feedback inhibits hexokinase
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Glucose -6 phosphate
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
17 - 17 letters in von Recklinghausen

3. Which anti breast cancer drugs work on micortubules
Paclitaxel
Flagella - cilia - mitotic spindles
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Phenylalanine hydroxylase

4. What makes up a nucleotide

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5. What is the target of the 3' hydroxyl attack
Vincritsine/vinblastine
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Carbomoyl phosphate synthetase I
The triphosphate bond

6. What is anticipation and give an example
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
N to C
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

7. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Catabolic processes to carry reducing equivalents away as NADH
Glycine - aspartate - glutamine
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Acetyl - CoA

8. What is loss of heterozygosity and give an example
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
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
Biotin
Histidine

9. Synthesis of vit B3 requires what other vitamin
2 rings
THFs
Fed
B6

10. What is the TX for pyruvate dehydrogenase deficiency
MRNA
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Hypoglycemia
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

11. nucleotide repeat for fragile x
X- linked recessive
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
CGG
Proline and lysine - vit C

12. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Muscle
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Autosomal recessive diseases
Pseudomonas and s aureus

13. What are the two transgenic strategies in mice
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Catabolic processes to carry reducing equivalents away as NADH
Modifies N- oligosaccharides

14. In eukaryotes - What does RNA poly II make
MRNA
Ketone - methyl
Acetyl - CoA to malonyl - CoA (2C to 3C)
Peroxide

15. What are the water soluble vitamins - which ones are stored
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
Core proteins
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
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

16. Where is fructose 1 -6 bisphosphatase found and What does it do
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Met - val - arg his

17. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Essential fructosuria - fructokinase AR
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Disorder of aromatic amino acid metabolism
Mutated dystrophin gene - less severe - adolescence

18. What is dominant negative mutation and give an example
Activates LCAT
OTC has hyperammonemia - orotic aciduira does not
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
Specific glycosylases - AP endonuclease

19. How do tetracyclines work
Superoxide dismutase
Ca/calmodulin in muscle to coordinate with muscle activity
High output cardiac failure - dilated cardiomyopathy - edema
Bind 30s subunit preventing attachment of aminoacyl - tRNA

20. What enzyme turns ROS to H2O2
Oxidizes substrate
Nissl body - enzyme and NTs
Chylomicrons
Superoxide dismutase

21. What are uncoupling agents
Catabolic processes to carry reducing equivalents away as NADH
Removal of N or C termal propeptides from zymogens to generate mature proteins
SAM
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

22. What enzyme converts phenylalanine to tyrosin
Isocitrate dehydrogenase
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Phenylalanine hydroxylase
Grows slowly - collapses quickly

23. What is the main source of folate
APC on chromosome 5
After citruline
Foliage - small reserve in liver - eat green leaves
Hereditary spherocytosis

24. Which phase of the HMP shunt is reversible and Which is irreversible
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Malonyl coa
Oxidative is irreversible
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

25. What happens in zinc def
NAD+
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

26. congenital deficiency of homogentisic acid oxidase in the degradative pathway of tyrosine to fumarate leading to dark connective tissue - brown pigmented sclera - urine turns black on standing - dz and worst complication
Alkaptonuria - may have debiliating arthralgias
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Blood - bone marrown - amniotic fluid - placental tissue
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1

27. What is Gowers maneuver
Assistance of upper extremities to stand up
Nonsense > missense > silent
GAA
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis

28. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
Nine
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
CTG
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis

29. How do macrolides and clindamycin work
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Core proteins
Binds 50S - blocking translocation

30. What rxn does propionyl - CoA carboxylase catalyze
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Phosphorylation - glycosylation - hydroxylation
Williams syndrome

31. energy malnutrition resulting in tissues and muscle wasting - loss of subQ fat - variable edema
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Marasmus - muscle wasting
Fed
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

32. Delivers dietary TGs to peripheral tissues - delivers cholesterol to liver in the form of remnants - mostly depleted of TGs - secreted by intestinal epith cells
Phosphorylation - glycosylation - hydroxylation
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Chylomicrons
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

33. What does commaless - nonoverlapping genetic code refer to...
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Adenosine to inosine
Read from a fixed starting point as a continuous sequence of bases

34. What 3 syndromes are associated with vit B1 def
P+q = 1
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Wernicke - korsakoff - dry and wet beriberi
Debranching enzyme

35. What is the hardy weinber heterozygote prevalence
2pq
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Collagen
CAG - 4

36. How is ammonium transported from muscle to the liver for urea cycle
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
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Inc glucagon - inc cAMP - inc PKA
ATP - citrate

37. What are the mRNA stop codons
Tropoelastin with fibrillin scafolding
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
UGA - UAA and UAG
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

38. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Proline and glycine (non glycosylated forms)
Ribose 5- P to PRPP
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Phenylethamolamine N methyl transferase

39. what gene is implicated in fragile X syndrome - and What is the mutation
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Protein
FMR1 gene - methylation - associated with chromosomal breakage
HDL

40. What does apoB100 do
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Neuralgia
Binds to LDL receptor - mediates VLDL secretion
Niacin - constituent of NAD and NADP - derived from tryptophan

41. Why is G6PD def more common among patients of african decent
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Protective against malaria
NF2 on chromosome 22
2 -4 DNP - aspirin

42. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Alpha1 antitrypsin
Marfans
AR
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

43. What initiates protein synthesis
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Phenylketones in urine
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex

44. What are the irreversible enzymes of gluconeogenesis
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Phosphofructokinase 1

45. ADPKD is associated with What additional conditions
NAD+
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Exons

46. What step of uric acid synthesis does xanthine oxidase catalyze
Mucus secreting globlet cells and antibody secreting plasma cells
Hypoxanthine to xanthing and xanthine to uric acid
Active secretion in lungs and GI - reabsorbs in skin
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

47. What are the complications/signs of familial hypercholesterolemia
Flank pain - hematuria - HTN - progressive renal failure
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Acetoacetate and beta hydroxybutyrate

48. What occurs to oxaloacetate in starvation and DKA
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Arginine
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Protective against malaria

49. What does apoA 1 do
MEN - 2A and 2B with ret gene
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Activates LCAT
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue

50. What is linkage disequilibrium
Nine
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Arg - lys - his - arg is most basic - has has no charge at body pH
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations