Test your basic knowledge |

Biochemistry

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Glutamate
Poly A polymerase - signal is AAUAA
IDL
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

2. What does a phosphatase do
PCR - denaturation - annealing - elongation
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Removes phosphate group from substrate
Read from a fixed starting point as a continuous sequence of bases

3. What is the RDE of the urea cycle
Protective against malaria
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
1 kind with multiple subunits
Carbomoyl phosphate synthetase I

4. What CETP do
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Mitochondria
Neither of 2 alleles is dominant - blood groups
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

5. What is the breakdown product of epi
Met - val - arg his
Metanephrine
Tyrosine
Protein

6. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
Microarrays
Actin and myosin
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
32 - malate aspartate shuttle

7. What substance inside the cells replenishes NADPH
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
OTC has hyperammonemia - orotic aciduira does not
G6PD
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis

8. What does inc phenylalanine lead to...
African Americans and Asians
Dec methionine - inc cystiene - inc B12/folate
Phenylketones in urine
Orotate precursor - with PRPP added later

9. What is the physiologic role of dystrophin
Cri du chat
EtOH dehydrogenase and acetaldehyde dehydrogenase
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy

10. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
Type II
Oxidative and nonoxidative - no ATP produced or used
Williams syndrome
17 - 17 letters in von Recklinghausen

11. What is a missense mutation
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Changed AA (convservative - new AA is similar in chemical structure)
Targets the proteins for lysosome
F16BP

12. What are the characteristics of prader willi syndrome How does it occur
Von hippel lindau - 3
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Mcardle's - skeletal muscle glycogen posphorylase

13. What does the golgi add to serine and threonine residues
O- oligosaccharaides
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
Neurons
Changed AA (convservative - new AA is similar in chemical structure)

14. What does the vimentin stain for
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
One
B12 and folate
Connective tissue

15. bilateral acoustic schwannomas - juvenile cataracts
Alpha and beta tubulin - dimers have two GTP bound
NF2 on chromosome 22
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

16. What are the teratogenic effects of vit A and What test must be ordered before starting a woman on isotreitinoin for severe acne
Ribos first then deoxyribos with ribonucleotide reductase
Cleft palate - cardiac abnl - pregs test
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Deamination

17. What test is used for B12 def
Purines= A - G pyrimidine = C - T (U)
Specific glycosylases - AP endonuclease
Schilling test
Oxidative and nonoxidative - no ATP produced or used

18. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Phosphofructokinase 1
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Zero

19. What is a frame shift
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Disease
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

20. In which structures do you find microtubules
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Degradation of TG stored in adipocytes
Flagella - cilia - mitotic spindles
Glucose 6 phosphatase

21. What are the findings in orotic aciduria
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Palate - facial and cardiac defects
Base + ribose + phosphate (3' -5') phosphodiester bond
Glucose - 2Pi - 2ADP - 2NAD+

22. characterize x linked dominant
Phenylalanine
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Von Gierke's - Pompe - Cori - McArdle

23. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
CAG - 4

24. What is the activated carrier for phosphoryl
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Same as sprint + OXPHOS
ATP
Asp and Glu

25. What is locus heterogeneity and give an example
Wobble
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
TTP

26. How do glucagon/epi lead to glycogenolysis
17 - 17 letters in von Recklinghausen
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Glucose - 2Pi - 2ADP - 2NAD+

27. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Pyruvate to oxaloacetate (3C to 4C)
B100 and E
Autosomal recessive diseases
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

28. I g fat = ? Kcal
Changed AA (convservative - new AA is similar in chemical structure)
Neurons
Disease
Nine

29. What is the activated carrier for electrons
Lysine and leucine
P2 +2pq+ = 1
NADPH
NADH - NADPH - FADH2

30. Why can't muscle produce in gluconeogenesis
5' to 3'
Acetyl - CoA to malonyl - CoA (2C to 3C)
Lacks glucose 6 phophatase
SNP

31. What inhibits the carnitine shuttle
OTC has hyperammonemia - orotic aciduira does not
Mitochondria
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Malonyl coa

32. What converts NE to epi
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
TTP
Phenylethamolamine N methyl transferase
Histidine

33. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
2pq
Familial hypercholesterolemia - hyperlipidemia type IIA

34. What does a phosphorylase do
CG- 3 > AT-2 - More CG content - melting point goes up
Adds an inorganic phosphate onto substrate without using ATP
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Failure to track objects or develop a social smile

35. What are the symptoms of vit A excess
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

36. What is NADPH's role inside RBCs
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Keep glutathione reduced so it can detoxify free radicals and peroxides
Fed
Thymic - parathyroid and cardiac

37. Type I bone
Grows slowly - collapses quickly
CAG
By inhibiting formation of the initiation complex and cause misreading of mRNA
BOne

38. What does vit E def cause
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
THFs
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
PFK - rate limiting enzyme

39. What components come together to make S- adenosyl methionine
1 -25 OH2 D3 = calcitriol
RRNA
ATP and methionine
Reads usual codon but inserts wrong AA

40. What are the two transgenic strategies in mice
Schwann cells - lens - retina - kidneys
Paclitaxel
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Anabolic processes as a supply of reducing equivalents

41. RNA poly can't proofread - but What can it do
Lactate
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
Initiate chains
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

42. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
SnRNPs
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Acetyl - CoA

43. How does chloramphenicol work
Inhibits 50S peptidyltransferase
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
X linked frame shif mutation
CTG

44. What is the RDE of gluconeogenesis
Familial hypercholesterolemia - hyperlipidemia type IIA
Tryosine hydroxylase
Fructose 1 -6 bisphosphate
1 kind with multiple subunits

45. What does glycosylation of pro alpha chian yield and What is the structure
Foliage - small reserve in liver - eat green leaves
Palate - facial and cardiac defects
HGPRT - defective purine salvage - excess uric acid production
Procollagen - triple helix of 3 alpha collagen chains

46. How do cardia glycosides work
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
FISH

47. What does the addition of mannose -6 phosphate do
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
ATP hyrdolysis couple to energetically unfavorable rxns
Failure to track objects or develop a social smile
Targets the proteins for lysosome

48. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
Acetly- CoA - CO2 - NADH
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
AR
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

49. What else can phosphoylate phosphorylase kinase
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Adds 2 carbon with the help of biotin
Ca/calmodulin in muscle to coordinate with muscle activity
Cytosol - F 1 -6 BP to fructose 6 Phosphate

50. Pts with albinism are at inc risk For what cancer
Skin
Dopamine beta hydroxylase
SnRNPs
Dec DNA - dec lymphos leads to SCID