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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. Where do you find elastin and What does it do
Actin and myosin
Acetly- CoA - CO2 - NADH
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
1 ring

2. What is the energy source for translocation
GTP
Schwann cells - lens - retina - kidneys
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
Marasmus - muscle wasting

3. What catacholamine step is SAM required for
Sulfation
Exercise: inc NAD/NADH - inc ADP - inc Ca
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Conversion of NE to epi

4. What step begins the urea cycle and What is the enzyme needed - Where does it happen
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Creat a nick in the helix to relieave supercoils created during replication
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
One

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

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6. What apolipoproteins are on chylomicrons
Zero
B48 - AIV - CII - E
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
X- linked recessive

7. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
UDP glucose pyrophosphorylase
Blood - bone marrown - amniotic fluid - placental tissue
X linked frame shif mutation

8. What is the purpose of the HMP shunt
IDL
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Phosphorylation - glycosylation - hydroxylation
Scrutinizes - hydrolyzes the bond

9. 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
FISH
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Ribos first then deoxyribos with ribonucleotide reductase
Degredation of TG circulating in chylomicrons and VLDLs

10. What causes Edwards syndrome and What is it
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
ATP
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

11. what gene is implicated in fragile X syndrome - and What is the mutation
FMR1 gene - methylation - associated with chromosomal breakage
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

12. What two pathways is carbomoyl phosphate involved in - and what enzyme deficiency leads to a build of carbamoyl phosphate leading to what element in pyrimidine synthesis
Connective tissue
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway
Dec DNA - dec lymphos leads to SCID

13. What substances inhibit phosphofructokinase -1
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Epithelial cells
Oxidized hemoglobin precipiated within RBCs
ATP - citrate

14. What reaction does adenosine deaminase normally catalyze
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Nissl body - enzyme and NTs
Methionine encode by only 1 codon (AUG)
Adenosine to inosine

15. 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
Isocitrate dehydrogenase
40 - 60 - 80
DsRNA promotes degradation of target mRNA knocking down gene expression

16. What CETP do
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Seals.
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Poly A polymerase - signal is AAUAA

17. What is axonemal dynein
Phenylalanine hydroxylase
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

18. What makes up a nucleoside
Makes RNA primer on which DNA poly III can initiate replication
Active secretion in lungs and GI - reabsorbs in skin
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Base + ribose

19. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
RER
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Read from a fixed starting point as a continuous sequence of bases

20. How does ouabain work
Defect in fibrillin
Inhibits the Na/K pump by binding the K side
Paclitaxel
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

21. what disease can cause pellagra
Biotin
Mitochondria
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Free ribosomes

22. What is the energy source for tRNA actication (charging)
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
ATP
Mebendazole/thiabendazole
Lacks glucose 6 phophatase

23. What initiates protein synthesis
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
NADPH
PMNs

24. What is the origin of replication
Particular sequence of DNA where replicatino begins - may be single of multiple
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
ATP and methionine

25. What metabolic rxns occur in both the cytoplasm and mitochondria
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Rb and p53
Reads usual codon but inserts wrong AA
Wernicke - korsakoff - dry and wet beriberi

26. What are the results of pancreatic insuff in CF
Anabolic processes as a supply of reducing equivalents
Ribos first then deoxyribos with ribonucleotide reductase
RNA poly II
Malabsorption and steatorrhea (ADEK)

27. In eukaryotes - What does RNA poly II make
Acetly- CoA - CO2 - NADH
MRNA
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles

28. What does a phosphatase do
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
B6
Glucose -6 phosphate
Removes phosphate group from substrate

29. What are the priorities for the body in fasting and starvation
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Supply sufficient glucose to brain and RBCs and to preserve protein
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)

30. What are Heinz bodies
CG- 3 > AT-2 - More CG content - melting point goes up
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Oxidized hemoglobin precipiated within RBCs
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

31. What is Gowers maneuver
Silencers
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Assistance of upper extremities to stand up
Ketone - methyl

32. bilateral acoustic schwannomas - juvenile cataracts
Mitochondria
NF2 on chromosome 22
Biotin
Sucrose = glucose + fructose - lactose = glucose + galactose

33. What clotting factors require vit K
II - VII - IX - X (1972) protein C and S
Ribose 5- P to PRPP
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Hereditary spherocytosis

34. what findings are associated with marfans
L form
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly

35. Where is hexokinase found - What is its Km and Vmax and what uninduces it
3' end (with CCA)
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Oligomycin
Read from a fixed starting point as a continuous sequence of bases

36. I g fat = ? Kcal
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Nine
Cri du chat
OTC has hyperammonemia - orotic aciduira does not

37. What are uncoupling agents
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Citrate - acetyl coa from mito to cyto
Exons

38. How is vit D stored
30 - 50 - 70
Autosomal recessive diseases
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
25OHD3

39. What inhibits the carnitine shuttle
Conversion of NE to epi
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
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
Malonyl coa

40. What is disulfiram used for
Peroxide
Reads usual codon but inserts wrong AA
Protein kinase A
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms

41. Which amino acids are elastin rich in
ATP and alanine
Proline and glycine (non glycosylated forms)
L form
II - VII - IX - X (1972) protein C and S

42. How do you diagnose CFTR
Malabsorption and steatorrhea (ADEK)
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Inc Cl - in sweat

43. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Inc insulin - dec cAMP - dec PKA
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Active secretion in lungs and GI - reabsorbs in skin
Cre - lox system

44. What is used to diagnose muscular dystrophies
Glucose 6 phosphate dehydrogenase (G6PD)
Adenosine to inosine
NADPH
Inc CPK and muscle biopsy

45. inc glycogen in muscle but can't break it down - painful muscle cramps - myglobinuria with strenuous exercise - dz and enzyme

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46. What does universal genetic code refer to and What are some exception
Glycolysis and aerobic respiration
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Dec DNA - dec lymphos leads to SCID
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

47. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Terminal regions - tropocollagen
Orotate precursor - with PRPP added later
Procollagen - triple helix of 3 alpha collagen chains
Flank pain - hematuria - HTN - progressive renal failure

48. Which aspect of the spliceosome do patients with lupus make antibodies against
SnRNPs
Adds an inorganic phosphate onto substrate without using ATP
L form
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase

49. In which state is PFK-2 active
Fed
Malonyl coa
Failure to track objects or develop a social smile
Nonsense > missense > silent

50. trinucleotide repeat fo myotonic dystrophy
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
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
NAD+
CTG