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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 amino acid precursor for GABA and glutathione
RRNA
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Glutamate

2. How do permanent cells grow and regenerate and What are examples of permanent cells
Defect in fibrillin
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive

3. What happens with dry beriberi
Inc Cl - in sweat
Polyneuritis - symmetrical muscle wasting
Oxalacetate
Disease

4. What are the blood glucose levels maintained by for days 1-3
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)
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Ketone - methyl
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis

5. Which anti breast cancer drugs work on micortubules
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Inc glucagon - inc cAMP - inc PKA
Paclitaxel

6. protein malnutrition resulting in skin lesions - edema and liver malfxn
Kwashiorkor - small child with swollen belly
Avidin
ATP and methionine
Anchor muscle fibers - primarily in skeletal and cardiac muscle

7. What does the deletion of the dystrophin gene lead to...
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Accelearted muscle breakdown
5' of the incoming nucleotide

8. What does the primary transcript combine with to form the spliceosome
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
SnRNPs and other proteins
G6PD
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

9. what gene is implicated in fragile X syndrome - and What is the mutation
FMR1 gene - methylation - associated with chromosomal breakage
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
Glutamine PRPP amidotransferase
Myeloperoxidase

10. What is the RDE of ketogenesis
Microtubules
HMG- CoA synthase
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
X linked frame shif mutation

11. What is the defect in fructose intolerance and What does it cause
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Mucus secreting globlet cells and antibody secreting plasma cells
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
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting

12. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
Oligomycin
TTP
MEN - 2A and 2B with ret gene
Fructose 1 -6 bisphosphate

13. What is locus heterogeneity and give an example
Conversion of NE to epi
Isocitrate dehydrogenase
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Uses ATP to add high energy phophate group onto substrate

14. What is Retin A used topically for
Williams syndrome
Nissl body - enzyme and NTs
B100
Wrinkles and acne

15. What does the TCA cycle produce per 1 acetyl CoA
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
30 - glycerol -3- phosphate shuttle
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA

16. What does the CFTR channel do in the lungs - GI tract and skin
Active secretion in lungs and GI - reabsorbs in skin
DsRNA promotes degradation of target mRNA knocking down gene expression
Malabsorption and steatorrhea (ADEK)
Inc CPK and muscle biopsy

17. What is imprinting and give an example

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18. decreases In what substances can cause PKU
Stored ATP - creatine phosphate - anaerobic glycolysis
PFK - rate limiting enzyme
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue

19. cytoskeletal elements associated with cilia - flagella - mitotic spindle - neurones and centrioles
Microtubules
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
5' of the incoming nucleotide
Binds 50S - blocking translocation

20. What is the purpose of the HMP shunt
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
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
NADPH

21. What are the mRNA stop codons
Hereditary spherocytosis
Methionine encode by only 1 codon (AUG)
Acetyl - CoA
UGA - UAA and UAG

22. Delivers dietary TGs to peripheral tissues - delivers cholesterol to liver in the form of remnants - mostly depleted of TGs - secreted by intestinal epith cells
Chylomicrons
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
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

23. What do the single stranded binding proteins do
Prevent strands from reannealing
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
G6PD
Activates LCAT

24. What are the glucogenic/ketogenic amino acids
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Ile - phe - thr - trp
Flagella - cilia - mitotic spindles
DTMP

25. What enzyme def can cause emphysema
Cre - lox system
Alpha1 antitrypsin
Chylomicrons
Mediates extra remnant take up

26. characterize x linked dominant
HDL
1 ring
APRT + PRPP
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

27. What happens at the smooth ER
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Seals.
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Site of steroid synthesis and detoxification of drugs and poisons

28. How many rings do purines have
II - VII - IX - X (1972) protein C and S
2 rings
Alpha and beta tubulin - dimers have two GTP bound
Degradation of TG remaining in IDL

29. What are pyrimidines made from
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Orotate precursor - with PRPP added later
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Alpha - ketoglutarate dehydrogenase complex

30. What is the limiting reagent in EtOH metabolism
NAD+
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Dopa decarboxylase

31. What is the energy source after day 3 of starvation
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
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
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Phenytoin - MTX - and sulfonamides

32. Which antihelminthe drugs work on microtubules
Mebendazole/thiabendazole
Huntingtons
Carbomoyl phosphate synthetase I
Lysine and leucine

33. What metabolic rxns occur in the cytoplasm
Four
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Unwinds DNA template at replcation fork
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons

34. What is the most common urea cycle disorder and What is the mode of inheritance?
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Base + ribose + phosphate (3' -5') phosphodiester bond
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Promotor - TATA box - and CAAT box - AT rich

35. What causes patau's syndrome and What is it
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
RRNA
Alkaptonuria - may have debiliating arthralgias

36. What can vit B3 be used to treat
Base + ribose
Oxidized hemoglobin precipiated within RBCs
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Hyperlipidemia

37. congenital microdeletion of long arm of chromosoe 7 with findings of elfin facies - mental retardation - hypercalcemia - well developed verbal skills - extreme friendliness with strangers - cardiovascular problems
Tuberous sclerosis
Williams syndrome
B100
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

38. Which RNA poly opens DNA at promotor site
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Arginine
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
RNA poly II

39. How is vit D stored
Carnitine shuttle - acyl - coa from cyto to mito
Phenylalanine hydroxylase
B48 - AIV - CII - E
25OHD3

40. What 3 steps in RNA processing occur after transcription

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41. What does Alports syndrome cause and why
Hyperlipidemia
Lariat shape in order and remove intron precisely and join 2 exons
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Binds to LDL receptor - mediates VLDL secretion

42. Why does alpha amanitin cause liver failure and Where is it found
Breaks down acyl - coa to acetyl coa groups in mito
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Inhibits RNA polymerase II - found in death cap mushrooms

43. peripheral neuropathy of hands/feet - angiokeratomas - CV/renal disease - dz - def enzyme - acc substrate - inherit
Nine
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

44. What does the mutation in the gene cause in protein synthesis
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Abnormal protein folding - degradation before reaching cell surface
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
Chylomicrons

45. What happens in termination of proteins synthesis
Stop codon is recognized by release factor - and completed protein is released from ribosome
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Catabolic processes to carry reducing equivalents away as NADH
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

46. What does a carboxylase do
Heterochromatin = HighlyCondensed
HGPRT - defective purine salvage - excess uric acid production
Liver and leafy veggies
Adds 2 carbon with the help of biotin

47. What is the amino acid precursor for histamine
Biotin
MEN - 2A and 2B with ret gene
Lacks glucose 6 phophatase
Histidine

48. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
Superoxide dismutase
25OHD3
Neurofibromatosis type 1 (von Recklinghausens disease)
Krabbes - galactocerebrosidase - galactocerebroside - AR

49. What does commaless - nonoverlapping genetic code refer to...
Read from a fixed starting point as a continuous sequence of bases
VMA
Removes phosphate group from substrate
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

50. Name 5 drugs that interfere with nucleotide synthesis
HMG- CoA (HMG- CoA to mevalonate
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Glycogen phosphorylase