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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 RDE of TCA cycle
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Isocitrate dehydrogenase
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
AMP - fructose 2 -6 BP

2. What defects characterize DiGeorge syndrome
Thymic - parathyroid and cardiac
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Oxidized hemoglobin precipiated within RBCs

3. Milder form of type I with nl blood lactate levels - dz and enzyme

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4. hepatosplenomegaly - aseptic necrosis of femur - bone crisis - MACS that look like crumpled tissue paper

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5. Adenosine deaminase deficiency is an important cause of what immunodeficiency?
Carnitine acyltransferase I
Inhibits the Na/K pump by binding the K side
Dec DNA - dec lymphos leads to SCID
Site of steroid synthesis and detoxification of drugs and poisons

6. What are the function of vit C
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
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
Poly A polymerase - signal is AAUAA
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

7. characterize autosomal domint inheritance
B48 - AIV - CII - E
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Dec DNA - dec lymphos leads to SCID
LCAT (lecithin cholesterol acyltransferase)

8. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Inc CPK and muscle biopsy
Marfans
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
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

9. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Tyrosine
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA

10. What are the glucogenic essential amino acids
Met - val - arg his
CFTR gene - 7 - Phe 508
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Pyruvate - NAD+ - CoA

11. Where is vit A found in the diet
Tropoelastin with fibrillin scafolding
Liver and leafy veggies
Glycine - aspartate - glutamine
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

12. ADPKD is associated with What additional conditions
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Met - val - arg his
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Autosomal recessive diseases

13. What do def in in enzymes of gluconeogenesis cause
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
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Hypoglycemia

14. What are the clinical features of I cell diesase
Defect in fibrillin
Neimann - pick - sphingomyelinase - sphingomyelin - AR
RER
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

15. What happens in termination of proteins synthesis
Locus heterogeneity - ocular albinism is x- linked recessive
Cytosol
Stop codon is recognized by release factor - and completed protein is released from ribosome
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates

16. What does the golgi add to serine and threonine residues
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Cyclin dependent kinases;constitutive and inactive
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)
O- oligosaccharaides

17. What is the most abundant type of RNA
Same AA - often base change in 3rd position of codon (tRNA wobble)
RRNA
Cytosol
Grows slowly - collapses quickly

18. What does the golgi apparatus do on asparagine
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Modifies N- oligosaccharides
Base + ribose + phosphate (3' -5') phosphodiester bond
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

19. Where is acetaldehyde located
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
DNA
Mitochondria

20. What does the addition of mannose -6 phosphate do
Targets the proteins for lysosome
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Creat a nick in the helix to relieave supercoils created during replication

21. What enzyme converts adenine to AMP
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
APRT + PRPP
CTG
Griseofulvin

22. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
SAM
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis

23. What does apoA 1 do
Activates LCAT
VLDL
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
CarTWOlage

24. What is the hardy weinber heterozygote prevalence
Alcohol version of glucose - can trap glucose in cell - aldose reductase
After day 1
2pq
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

25. What are the functinos of vitamin A
Diphyllobothrium latum
Active secretion in lungs and GI - reabsorbs in skin
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
B48 - AIV - CII - E

26. Which type of chromatin is less condensed - transcriptionally active - sterically accesible
Deamination
Kidney - ears - eyes
Euchromatin
Flank pain - hematuria - HTN - progressive renal failure

27. What is the results of vit B1 def
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
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
SAM
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

28. What enzyme degrades a small amount of glycogen in lysosomes
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Essential fructosuria - fructokinase AR
Alpha 1 -4 glucosidase

29. What is the RDE of glycogen synthesis
DNA
II - VII - IX - X (1972) protein C and S
MRNA - tRNA
Glycogen synthase

30. Which cells are rich in smooth ER
VMA
Griseofulvin
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Liver hepatocytes and steroid producing cells of the adrenal cortex

31. What shuttle is involved in fatty acid synthesis and What does it move From where to where
Actin and myosin
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Citrate - acetyl coa from mito to cyto
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

32. congenital microdeletion of short arm of chromosome 5 with microcephaly - moderate to severe mental retardation - high pitched crying/meying - epicanthal folds - cardiac abnl
Cri du chat
Collagen
Hyperlipidemia
B100 and E

33. What is heteroplasmy
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Polyneuritis - symmetrical muscle wasting
Familial hypercholesterolemia - hyperlipidemia type IIA
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

34. What does vit B3 def result in
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Orotate precursor - with PRPP added later
VLDL
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

35. pyruvate carboxylase catalyzes what rxn
Pyruvate to oxaloacetate (3C to 4C)
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
1 -25 OH2 D3 = calcitriol
2 -4 DNP - aspirin

36. What tissues have only aldose reductase
Promotor - TATA box - and CAAT box - AT rich
Schwann cells - lens - retina - kidneys
Fructose 1 -6 bisphosphate
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

37. How do cardia glycosides work
Binds 50S - blocking translocation
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Glycolysis and aerobic respiration
APKD1 on chromosome 16

38. What is DNA cloning and How do you do it?
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Read from a fixed starting point as a continuous sequence of bases
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA

39. What are the names and sources of the two types of vit D found in nature
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
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
Targets the proteins for lysosome
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

40. What enzyme becomes essential in PKU
Marfans
Lariat shape in order and remove intron precisely and join 2 exons
Tyrosine
Carnitine acyltransferase I

41. What does biotin def cause
17 - 17 letters in von Recklinghausen
Dermatitis - alopecia - enteritis
HMG- CoA reductase
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR

42. characterize mitochondrial inheritance
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Transfers methyl units
Transmitted only through mother - all offspring of affected females may show signs of disease
Methionine encode by only 1 codon (AUG)

43. What are pyrimidines made from
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Orotate precursor - with PRPP added later
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol

44. NADPH are used In what 4 things
Von Gierke's - Pompe - Cori - McArdle
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
CFTR gene - 7 - Phe 508

45. What does apoB48 do
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Mediates chylomicron secretion
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Malapsorption syndromes like sprue or CF or mineral oil intake

46. What is the activated carrier for electrons
HMG- CoA (HMG- CoA to mevalonate
FMR1 gene - methylation - associated with chromosomal breakage
NADH - NADPH - FADH2
Protein kinase A

47. Which kind of osteogenesis imperfecta is fata in utero or in neonatal period
Type II
Medial dorsal nucleus of thalamus - mamillary bodies
Change resulting in early stop codon
Covalent cross - linking by lysyl oxidase to make collagen fibrils

48. Very Poor Carbohydrate Metabolism stands for 4 of the glycogen storage diseases - What are thy

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49. What are cyclins
Protective against malaria
2pq
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Promotor - TATA box - and CAAT box - AT rich

50. What causes maple syrup urine disease and What does it lead to...
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
Must be both activated and inactivated for cell cycle to progress
FISH
Degradation of TG remaining in IDL