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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 are the priorities for the body in fasting and starvation
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
ATP - citrate
Supply sufficient glucose to brain and RBCs and to preserve protein

2. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
More than 1 codon may code for the same amino acid
Inc glucagon - inc cAMP - inc PKA
Sucrose = glucose + fructose - lactose = glucose + galactose
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact

3. facial lesions - hypopigmented 'ash leaf spots -' cortical and retinal hamartomas - seizures - mental retardation - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas - inc risk of astrocytomas
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Tuberous sclerosis
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
Oxidizes substrate

4. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
Removal of N or C termal propeptides from zymogens to generate mature proteins
Orotic acid to UMP
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue

5. trinucleotide repeat fo myotonic dystrophy
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Cri du chat
CTG

6. What are the results of CF on male fertility
Arg - lys - his - arg is most basic - has has no charge at body pH
Purines= A - G pyrimidine = C - T (U)
Males are infertile due to bilateral absence of vas deferens
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

7. What is the amino acid precursor for GABA and glutathione
Removes phosphate group from substrate
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Glutamate
Glycogen phosphorylase

8. What is axonemal dynein
2pq
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
40 - 60 - 80
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

9. What polar group does guanine have - and what non polar group does thymine have
1 ring
Metanephrine
Ketone - methyl
Sucrose = glucose + fructose - lactose = glucose + galactose

10. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Seals.
Familial hypercholesterolemia - hyperlipidemia type IIA
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

11. pyruvate carboxylase catalyzes what rxn
1 kind with multiple subunits
Pyruvate to oxaloacetate (3C to 4C)
Mucus secreting globlet cells and antibody secreting plasma cells
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

12. What co - factors are required for the pyruvated dehydrogenase complex
Stored ATP - creatine phosphate - anaerobic glycolysis
THFs
Seals.
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

13. What is the complication of cystinuria
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Acetyl - CoA to malonyl - CoA (2C to 3C)
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond

14. What initiates protein synthesis
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Karyotyping

15. What is the amino acid precursor for porphyrin and heme
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
HVA
Glycine

16. Gene imprinting implies that How many alleles are active at a single locus
Foliage - small reserve in liver - eat green leaves
Reads usual codon but inserts wrong AA
One
Specific glycosylases - AP endonuclease

17. In eukaryotes - What does RNA poly I make
Same AA - often base change in 3rd position of codon (tRNA wobble)
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
1 -25 OH2 D3 = calcitriol
RRNA

18. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
RER
Microarrays
Removes phosphate group from substrate

19. What does Citrate Is Krebs starting substrate for making oxaloacetate
Neurofibromatosis type 1 (von Recklinghausens disease)
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Neuralgia
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate

20. The pyruvate dehydorgenase complex serves In what reaction: reactants
CAG
MRNA
Degredation of TG circulating in chylomicrons and VLDLs
Pyruvate - NAD+ - CoA

21. What happens in vit D def
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Inhibits the Na/K pump by binding the K side
After day 1
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

22. What shuttle is used in fatty acid degredation and What does it move and From where to where
Neurons
Medial dorsal nucleus of thalamus - mamillary bodies
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Carnitine shuttle - acyl - coa from cyto to mito

23. Name 5 drugs that interfere with nucleotide synthesis
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Oligomycin
Free ribosomes
APRT + PRPP

24. What is I cell disease
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
3' end (with CCA)
Acetoacetate and beta hydroxybutyrate
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

25. Why enzyme breaks down elastin and what enzyme inhibits it
SNP
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Elastase - inhibited by alpha1 antitrypsin
Liver - also in kidney and gut epithelium

26. What happens do glycogen in skeletal muscle during exercise
HVA
GTP
Liver hepatocytes and steroid producing cells of the adrenal cortex
Glycogenolysis to form glucose

27. nucleotide repeat for fredreich's ataxia
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
GAA
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
High output cardiac failure - dilated cardiomyopathy - edema

28. What does GFAP stain for
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Neuralgia

29. A small proportion of Down syndrome is due to What two genetic events
Two
Breaks down acyl - coa to acetyl coa groups in mito
APKD1 on chromosome 16
Robertsonian translocation and mosaicism

30. What apolipoprotiens are on VLDL
Oxalacetate
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
B-100 - CII and E

31. Type II cartilage
Wernicke - korsakoff - dry and wet beriberi
Read from a fixed starting point as a continuous sequence of bases
Removal of N or C termal propeptides from zymogens to generate mature proteins
CarTWOlage

32. What is anticipation and give an example
Procollagen - triple helix of 3 alpha collagen chains
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
CAG - 4
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

33. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
Alpha - ketoglutarate dehydrogenase complex
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Oxalacetate

34. What two cells are particularly rich in RER
Sulfation
Epithelial cells
Mucus secreting globlet cells and antibody secreting plasma cells
Paclitaxel

35. What are the mRNA stop codons
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
UGA - UAA and UAG
PCR - denaturation - annealing - elongation

36. In base excision repaire - what recognizes and removes damaged bases and what cuts the DNA to remove the empty sugar
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
Specific glycosylases - AP endonuclease
Orotic acid to UMP
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact

37. energy malnutrition resulting in tissues and muscle wasting - loss of subQ fat - variable edema
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Sucrose = glucose + fructose - lactose = glucose + galactose
Marasmus - muscle wasting
1 -25 OH2 D3 = calcitriol

38. What is the defect in II A familial hypercholesterolemia
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Euchromatin
FMR1 gene - methylation - associated with chromosomal breakage
Proton gradient

39. What enzyme turns ROS to H2O2
Microarrays
Superoxide dismutase
Inc dicarboxylic acids - dec in glucose and ketones
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

40. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
Terminal regions - tropocollagen
Glycogenolysis to form glucose
Infection - free radicals generated by inflammatory response
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis

41. What is a nonsense mutation
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Glucose - 2Pi - 2ADP - 2NAD+
Change resulting in early stop codon
Transfers methyl units

42. What apolipoprotein is on LDL
B100
Malabsorption and steatorrhea (ADEK)
ADPKD
Dec methionine - inc cystiene - inc B12/folate

43. What does Ehlers Danlos cause and why
Must be both activated and inactivated for cell cycle to progress
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Promotor - TATA box - and CAAT box - AT rich
Sulfation

44. What is the RDE of glycogen synthesis
Four
Change resulting in early stop codon
RNA poly II
Glycogen synthase

45. What causes Down syndrome
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
N to C
APRT + PRPP

46. What does the passage of electrons result in that when coupled to OXPHOS drives the production of ATP
Silencers
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
B12 and folate
Proton gradient

47. What occurs to oxaloacetate in starvation and DKA
PCR - denaturation - annealing - elongation
Elastase - inhibited by alpha1 antitrypsin
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

48. What are the fetal screening measures for Down
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Cofactor for LPL
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

49. What are the findings in orotic aciduria
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Pyruvate - NAD+ - CoA
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy

50. What is a silent mutation
Terminal regions - tropocollagen
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Tyrosine
Same AA - often base change in 3rd position of codon (tRNA wobble)