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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 does commaless - nonoverlapping genetic code refer to...
Alpha and beta tubulin - dimers have two GTP bound
Read from a fixed starting point as a continuous sequence of bases
Lysine and arginine
LCAT (lecithin cholesterol acyltransferase)

2. What is NADPH's role inside RBCs
Ile - phe - thr - trp
Keep glutathione reduced so it can detoxify free radicals and peroxides
TRNA
Muscle

3. trinucleotide repeat fo myotonic dystrophy
CTG
Hereditary spherocytosis
Ile - phe - thr - trp
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

4. If two alleles are present - but the active allele is deleted - what happens
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
HDL
Disease
L form

5. What does Ehlers Danlos cause and why
Creat a nick in the helix to relieave supercoils created during replication
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Mutated dystrophin gene - less severe - adolescence
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

6. What does aminoacyl tRNA synthetase do the AA before and after it binds to tRNA - and what happens if it's the wrong the match
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Scrutinizes - hydrolyzes the bond
Glucose - 2Pi - 2ADP - 2NAD+
TTP

7. Which carbon bears the triphosphate and the energy source for bond formation

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8. When are glycogen reserves depleted
Removal of N or C termal propeptides from zymogens to generate mature proteins
Nine
Y shaped region along the DNA template where leading nad lagging strands are synthesized
After day 1

9. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
LDL
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine

10. What happens with wet beriberi
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
High output cardiac failure - dilated cardiomyopathy - edema
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

11. Where is PEP carboxykinase found - What does it do - and What does it require
Proton gradient
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Oxidative is irreversible

12. Fluorescent DNA or RNA probe binds to specific gene of interest - used for specific localization of genes and direct visualization of anomalies - like microdeletions - at molecular level
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Liver - ovaries - seminal vesicles
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
FISH

13. What is the energy source in the fed state right after a meal
Glycolysis and aerobic respiration
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
Malonyl coa
Supply sufficient glucose to brain and RBCs and to preserve protein

14. What is the activated carrier for methyl groups
SAM
Poly A polymerase - signal is AAUAA
Disease
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

15. What is linkage disequilibrium
Marasmus - muscle wasting
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations

16. ADPKD is associated with What additional conditions
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
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
Arg and his inc in histones Which bind negatively charged DNA

17. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Wernicke - korsakoff - dry and wet beriberi
PFK - rate limiting enzyme
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

18. What happens in zinc def
Two
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

19. What does universal genetic code refer to and What are some exception
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
ATP hyrdolysis couple to energetically unfavorable rxns
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints

20. What does apoCII do
Cofactor for LPL
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Kidney - ears - eyes

21. 1 g of protein or cabrohydrate = ?kcal
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Four
Nissl body - enzyme and NTs
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

22. What does amino acid catabolsim results in the formation of what?
Mcardle's - skeletal muscle glycogen posphorylase
Neg to pos
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

23. How many rings do purines have
Degredation of dietary TG in small intestine
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
2 rings

24. What ribosomes do prokaryotes have
30 - 50 - 70
AR
Defect in fibrillin
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

25. What substance inside the cells replenishes NADPH
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Protective against malaria
G6PD
Alpha1 antitrypsin

26. What are purines made from
Nine
Enhancers
Type II
IMP precursor

27. congenital microdeletion of short arm of chromosome 5 with microcephaly - moderate to severe mental retardation - high pitched crying/meying - epicanthal folds - cardiac abnl
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Cri du chat
Alkaptonuria - may have debiliating arthralgias
Dec methionine - inc cystiene - inc B12/folate

28. characterize autosomal recessive inheritance
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
In ER - glucose 6- P to glucose
1/4 of offspring from 2 carrier parents are affected - often enzyme def - usually only seen in 1 generation - often more sever than AD - presents in childhood
Myeloperoxidase

29. characterize autosomal domint inheritance
Each codon specifies only 1 amino acid
Alpha1 antitrypsin
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

30. What is the composition of urea and where do each part derive from
Acetly- CoA - CO2 - NADH
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Phenylketones in urine
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

31. What is the trinucleotide repeat in fragile X
CGG
More than 1 codon may code for the same amino acid
Acetoacetate and beta hydroxybutyrate
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA

32. What is RNAi used for
DsRNA promotes degradation of target mRNA knocking down gene expression
Lariat shape in order and remove intron precisely and join 2 exons
Makes RNA primer on which DNA poly III can initiate replication
Promotor - TATA box - and CAAT box - AT rich

33. What co - factors are required for the pyruvated dehydrogenase complex
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Breaks down acyl - coa to acetyl coa groups in mito
Two
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

34. Where are FADH2 electrons transferred to...
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Comlex II
Fed

35. several distinct syndromes characterized by familial tumors of endocrine glands including pancreas - parathyroid - pituitary - thryoid and adrenal medulla - disorders and gene association
Glycine - aspartate - glutamine
Targets the proteins for lysosome
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
MEN - 2A and 2B with ret gene

36. What are covalent alterations
Specific glycosylases - AP endonuclease
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Phosphorylation - glycosylation - hydroxylation
Alkaptonuria - may have debiliating arthralgias

37. What is the amino acid precursor for histamine
Same as sprint + OXPHOS
Histidine
Activates LCAT
RER

38. What happens in the first stage of collagen synthesis - and Where does it happen
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Same AA - often base change in 3rd position of codon (tRNA wobble)
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
After citruline

39. What CETP do
Specific glycosylases - AP endonuclease
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
2 rings
Ca/calmodulin in muscle to coordinate with muscle activity

40. What is the rate determining enzyme (RDE) of glycolysis
Transmitted only through mother - all offspring of affected females may show signs of disease
Protein kinase A
Phosphofructokinase 1
Anabolic processes as a supply of reducing equivalents

41. Where are cytosolic and organellar proteins made
DsRNA promotes degradation of target mRNA knocking down gene expression
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Alpha - ketoglutarate dehydrogenase complex
Free ribosomes

42. What does glycosylation of pro alpha chian yield and What is the structure
Procollagen - triple helix of 3 alpha collagen chains
Promotor - TATA box - and CAAT box - AT rich
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

43. What happens in vit D def
UDP glucose pyrophosphorylase
MRNA
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

44. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
Microarrays
Neural tube
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

45. Which direction does dynein go
Post to neg
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

46. Which aspect of the spliceosome do patients with lupus make antibodies against
RRNA
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
SnRNPs
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS

47. What is the defect in cystinuria
9+2 arrangement of microtubules
TRNA
Mediates extra remnant take up
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

48. For eukaryotes - Where does replication begin?
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Consesus sequenec of base pairs
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Arginine

49. Pts with albinism are at inc risk For what cancer
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
Skin
Poly A polymerase - signal is AAUAA
Lactate

50. What liberates glucose from glucose 6 P
Glucose 6 phosphatase
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
GAA