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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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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What are the complications/signs of familial hypercholesterolemia
Euchromatin
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Binds 50S - blocking translocation

2. what gene is implicated in fragile X syndrome - and What is the mutation
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Core proteins
Y shaped region along the DNA template where leading nad lagging strands are synthesized
FMR1 gene - methylation - associated with chromosomal breakage

3. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Essential fructosuria - fructokinase AR
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
Purines= A - G pyrimidine = C - T (U)

4. What is kartageners syndrome
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Purines= A - G pyrimidine = C - T (U)
Liver hepatocytes and steroid producing cells of the adrenal cortex

5. Inhibition of thymidilate synthase and and DHFR lead to decrease In what substance
DTMP
Blood - bone marrown - amniotic fluid - placental tissue
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Histidine

6. What is the amino acid precuros for niacin and serotonin/melatonin
Phenylalanine
Tryptophan
APRT + PRPP
Alkaptonuria - may have debiliating arthralgias

7. How do macrolides and clindamycin work
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Dopamine beta hydroxylase
Binds 50S - blocking translocation
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization

8. What does apoA 1 do
Collagen
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Fasting
Activates LCAT

9. What is DNA cloning and How do you do it?
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
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
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

10. What is the function and name of vit B6
Bruton's agammaglobulinemia - wiskott - aldrich - fabrys disease - G6PD def - ocular albinism - Lesch - Nyhan syndrome - Duchenne and Becker Muscular Dystrophy - hunter's syndrome - hemophilia A and B
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
2 rings
Glycolysis and aerobic respiration

11. What residues are hydroxylated in step 2 of collagen synthesis - and What does this require
Cyclin dependent kinases;constitutive and inactive
Terminal regions - tropocollagen
Proline and lysine - vit C
Heterochromatin = HighlyCondensed

12. What does hartnups disease cause
Carnitine acyltransferase I
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine

13. What apolipoprotiens are on VLDL
Carbomoyl phosphate synthetase II
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
CGG
B-100 - CII and E

14. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
Orotic acid to UMP
Uses ATP to add high energy phophate group onto substrate
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Fibroblast

15. What is the RDE of ketogenesis
Disease
Cofactor for LPL
Attachment of ubiquitin to defective proteins tag them for breakdown
HMG- CoA synthase

16. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
Metanephrine
ATP
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

17. How do labile celss grow and regenerate and What are examples
B48 - AIV - CII - E
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
B100 and E

18. What causes Marfan syndrome
Defect in fibrillin
Isocitrate dehydrogenase
40 - 60 - 80
Mutated dystrophin gene - less severe - adolescence

19. recurrent pulmonary infxns in CF are due to what organisms
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
UDP glucose pyrophosphorylase
Inc vit B6
Pseudomonas and s aureus

20. Accurate base pairing is required only in the first two nucleotide positions of an mRNA codon - so conds differeing in the 3rd position may code for the same tRNA/AA due to degenerate genetic code
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Wobble
Phenylalanine hydroxylase
Stored ATP - creatine phosphate - anaerobic glycolysis

21. How many rings do pyrimidines have
1 ring
Ca/calmodulin in muscle to coordinate with muscle activity
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Peroxide

22. What is made fir rNucleotides or deoxyrNucleotides and what enzyme is necessary to convert one to the next
Ribos first then deoxyribos with ribonucleotide reductase
Kidney - ears - eyes
Cyclin dependent kinases;constitutive and inactive
Proline and lysine - vit C

23. What happens in carnitine def
Consesus sequenec of base pairs
1 -25 OH2 D3 = calcitriol
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Sucrose = glucose + fructose - lactose = glucose + galactose

24. What kind of branches do glycogen branches have
Tryosine hydroxylase
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Alpha 1 -6 and alpha 1 -4
CAG

25. Which part of the DNA binds RNA polymerase and multiple other TFs upstream from gene locus
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
Grows slowly - collapses quickly
Promotor - TATA box - and CAAT box - AT rich
L form

26. What does the TCA cycle produce per 1 acetyl CoA
ADPKD
Glycogen and FFA oxidation; glucose conserved for final sprinting
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Cyclin dependent kinases;constitutive and inactive

27. Why does alpha amanitin cause liver failure and Where is it found
Collagen
Neuralgia
Inhibits RNA polymerase II - found in death cap mushrooms
1 -25 OH2 D3 = calcitriol

28. 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
Phosphorylation - glycosylation - hydroxylation
CGG
Phenytoin - MTX - and sulfonamides

29. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
Liver hepatocytes and steroid producing cells of the adrenal cortex
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Blood - bone marrown - amniotic fluid - placental tissue
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)

30. What is the smallest mutation a mircoarray can detect
SNP
F16BP
Phosphofructokinase 1
Mutated dystrophin gene - less severe - adolescence

31. Adenosine deaminase deficiency is an important cause of what immunodeficiency?
Dec DNA - dec lymphos leads to SCID
Fibrofatty replacement of muscle - cardiac myopathy
5' of the incoming nucleotide
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes

32. What two proteins make up microtubules and how are they arranged
Citrate - acetyl coa from mito to cyto
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Disease
Alpha and beta tubulin - dimers have two GTP bound

33. What happens in folate def
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
30 - 50 - 70
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs

34. What are the glucogenic essential amino acids
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Familial hypercholesterolemia - hyperlipidemia type IIA
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Met - val - arg his

35. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Oxidative and nonoxidative - no ATP produced or used
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Degredation of TG circulating in chylomicrons and VLDLs

36. In what cells do the respiratory burst occur
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
PMNs
Coenzyme A - lipoamide
Flank pain - hematuria - HTN - progressive renal failure

37. trinucleotide repeat fo myotonic dystrophy
Carbomoyl phosphate synthetase I
CTG
Neurofibromatosis type 1 (von Recklinghausens disease)
Carbomoyl phosphate synthetase II

38. What does apoB100 do
Binds to LDL receptor - mediates VLDL secretion
Makes RNA primer on which DNA poly III can initiate replication
Accelearted muscle breakdown
GTP

39. How are the many staggered tropocollagen molecules reinforced
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Covalent cross - linking by lysyl oxidase to make collagen fibrils

40. Which enzyme involved in RNA synthesis does not require a template
Protein kinase A
Skin
Robertsonian translocation and mosaicism
Poly A polymerase - signal is AAUAA

41. Why enzyme breaks down elastin and what enzyme inhibits it
9+2 arrangement of microtubules
Elastase - inhibited by alpha1 antitrypsin
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Inhibits the Na/K pump by binding the K side

42. Which antihelminthe drugs work on microtubules
Glucose - 2Pi - 2ADP - 2NAD+
Mebendazole/thiabendazole
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Schilling test

43. What causes Down syndrome
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Neurons
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins

44. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
No - its non homologous
Night blindness - dry skin
Terminal regions - tropocollagen

45. ADPKD is associated with What additional conditions
Exercise: inc NAD/NADH - inc ADP - inc Ca
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Marfans
Degradation of TG stored in adipocytes

46. What makes up a nucleotide

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47. What are the 4 assumption of the Hardy Weinberg law
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Carbomoyl phosphate synthetase I
DsRNA promotes degradation of target mRNA knocking down gene expression

48. What is the fxn of vit E
Foliage - small reserve in liver - eat green leaves
Mucus secreting globlet cells and antibody secreting plasma cells
Basement membrane or basal lamina
Antioxidant - protects RBCs and membrances from free radical damage

49. What are the fat soluble vitamins and What does their absorption depend on...
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Mebendazole/thiabendazole
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Pyruvate to oxaloacetate (3C to 4C)

50. What step of uric acid synthesis does xanthine oxidase catalyze
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Exons
Hypoxanthine to xanthing and xanthine to uric acid
Phosphofructokinase 1