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. What is the RER called in neurons and What is made there
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
SNP
Nissl body - enzyme and NTs

2. How do labile celss grow and regenerate and What are examples
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Peroxide
NF2 on chromosome 22

3. What does vit B3 def result in
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Myeloperoxidase
LCAT (lecithin cholesterol acyltransferase)
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

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

5. What are the clinical features of I cell diesase
Mcardle's - skeletal muscle glycogen posphorylase
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Targets the proteins for lysosome
Fibroblast

6. What are the complications/signs of familial hypercholesterolemia
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
AR
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

7. What is the energy source for tRNA actication (charging)
ATP
VMA
Grows slowly - collapses quickly
NADPH

8. What is the breakdown product of epi
Arg - lys - his - arg is most basic - has has no charge at body pH
Metanephrine
Unmethylated - newly synthesized - HNPCC
Adenosine to inosine

9. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Consesus sequenec of base pairs
Oxalacetate

10. Delivers dietary TGs to peripheral tissues - delivers cholesterol to liver in the form of remnants - mostly depleted of TGs - secreted by intestinal epith cells
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Ribos first then deoxyribos with ribonucleotide reductase
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Chylomicrons

11. Which cells are rich in smooth ER
Must be both activated and inactivated for cell cycle to progress
2pq
Liver hepatocytes and steroid producing cells of the adrenal cortex
Medial dorsal nucleus of thalamus - mamillary bodies

12. What does the passage of electrons result in that when coupled to OXPHOS drives the production of ATP
Tryptophan
APRT + PRPP
Proton gradient
THFs

13. What is the RDE of fatty acid synthesis
Kwashiorkor - small child with swollen belly
Carbomoyl phosphate synthetase II
Acetyl - CoA carboxylase (ACC)
Covalent cross - linking by lysyl oxidase to make collagen fibrils

14. what findings are associated with marfans
More than 1 codon may code for the same amino acid
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Catabolic processes to carry reducing equivalents away as NADH
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty

15. What does vit C def cause
Oxalacetate
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Lysine and leucine

16. The pyruvate dehydorgenase complex serves In what reaction: reactants
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
DNA
Pyruvate - NAD+ - CoA

17. Which kind of osteogenesis imperfecta is fata in utero or in neonatal period
Consesus sequenec of base pairs
Type II
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
B-100 - CII and E

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

19. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
MRNA
Blood - bone marrown - amniotic fluid - placental tissue
Terminal regions - tropocollagen
Inc melt - dec fluidity

20. What are the priorities for the body in fasting and starvation
Supply sufficient glucose to brain and RBCs and to preserve protein
B100 and E
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
Huntingtons

21. What occurs to oxaloacetate in starvation and DKA
Tryosine hydroxylase
Alpha and beta tubulin - dimers have two GTP bound
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
1 ring

22. What are the blood glucose levels maintained by for days 1-3
Tryptophan
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)
High output cardiac failure - dilated cardiomyopathy - edema
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

23. What happens in folate def
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Microarrays
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate

24. What chromosome is the NF gene on...
17 - 17 letters in von Recklinghausen
Comlex II
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Chylomicrons

25. what happens in acyl coa dehyrdogenase def
Free ribosomes
Marasmus - muscle wasting
Glucose -6 phosphate
Inc dicarboxylic acids - dec in glucose and ketones

26. Which tumor suppresors inhibit G1 to S progression - where mutations result in unrestrained growth
Mucus secreting globlet cells and antibody secreting plasma cells
Eu - methionine - pro - formyl - methionine
Rb and p53
Cytosol

27. A small proportion of Down syndrome is due to What two genetic events
Paclitaxel
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
Robertsonian translocation and mosaicism
Dec methionine - inc cystiene - inc B12/folate

28. What enzyme def can cause emphysema
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Neither of 2 alleles is dominant - blood groups
Core proteins
Alpha1 antitrypsin

29. trinucleotide repeat fo myotonic dystrophy
Niacin - constituent of NAD and NADP - derived from tryptophan
Malabsorption and steatorrhea (ADEK)
CTG
More than 1 codon may code for the same amino acid

30. What amino acid makes up most of the octamer
Lysine and arginine
Facial flushing
Specific glycosylases - AP endonuclease
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

31. What is the TX for pyruvate dehydrogenase deficiency
II - VII - IX - X (1972) protein C and S
Krabbes - galactocerebrosidase - galactocerebroside - AR
TTP
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

32. What does DNA poly III do?

33. What is proteasomal degredation
Diphyllobothrium latum
Glycogen and FFA oxidation; glucose conserved for final sprinting
Attachment of ubiquitin to defective proteins tag them for breakdown
Connective tissue

34. What apolipoproteins are on chylomicrons
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
B48 - AIV - CII - E
Dec methionine - inc cystiene - inc B12/folate
Foliage - small reserve in liver - eat green leaves

35. What does a northern blot use as its sample
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
HMG- CoA synthase
RNA
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

36. Where is hexokinase found - What is its Km and Vmax and what uninduces it
In ER - glucose 6- P to glucose
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
30 - 50 - 70

37. What does a southern blot use as its sample
Liver and leafy veggies
Cri du chat
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
DNA

38. What bone disorder has x linked dominant inheritance
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
DsRNA promotes degradation of target mRNA knocking down gene expression
2pq

39. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
AMP - fructose 2 -6 BP
Palate - facial and cardiac defects
Ribose 5- P to PRPP
OTC has hyperammonemia - orotic aciduira does not

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

41. What are the irreversible enzymes of gluconeogenesis
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Oligomycin
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

42. What causes maple syrup urine disease and What does it lead to...
2pq
Basement membrane or basal lamina
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
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response

43. characterize autosomal domint inheritance
LDL
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Post to neg

44. Why can't even chain fatty acids produce new glucose
Facial flushing
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
They yield only acetyl - CoA equivalents
Cartilage - hyaline - vitreous body - nucleus pulposus

45. What is the results of vit B1 def
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
NAD+
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light

46. What are the mRNA stop codons
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
B12 and folate
UGA - UAA and UAG

47. Which are the acidic amino acids
Asp and Glu
Purines= A - G pyrimidine = C - T (U)
N to C
Arg and his inc in histones Which bind negatively charged DNA

48. congenital deficiency of homogentisic acid oxidase in the degradative pathway of tyrosine to fumarate leading to dark connective tissue - brown pigmented sclera - urine turns black on standing - dz and worst complication
Alkaptonuria - may have debiliating arthralgias
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Exercise: inc NAD/NADH - inc ADP - inc Ca
SnRNPs

49. If two alleles are present - but the active allele is deleted - what happens
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Disease

50. What form of amino acids are found in proteins
Uses ATP to add high energy phophate group onto substrate
SnRNPs
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
L form