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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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1. What is the activated carrier for phosphoryl
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
ATP
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
1 ring

2. What does the mutation in the gene cause in protein synthesis
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
Glycogenolysis to form glucose
Abnormal protein folding - degradation before reaching cell surface
Mitochondria

3. What is the origin of replication
Particular sequence of DNA where replicatino begins - may be single of multiple
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Marasmus - muscle wasting
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

4. What are the symptoms of vit A def
B6
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Night blindness - dry skin

5. Where is acetaldehyde located
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Unwinds DNA template at replcation fork
Mitochondria
Eu - methionine - pro - formyl - methionine

6. What residues are hydroxylated in step 2 of collagen synthesis - and What does this require
Active secretion in lungs and GI - reabsorbs in skin
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Proline and lysine - vit C

7. What is the Name and function of vit B1
Disorder of aromatic amino acid metabolism
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Dec methionine - inc cystiene - inc B12/folate
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage

8. What is the RDE of ketogenesis
Von gierkes - glucose 6 phosphatase
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Consesus sequenec of base pairs
HMG- CoA synthase

9. What are the products for glycolysis
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
1 -25 OH2 D3 = calcitriol
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

10. What is the TX for pyruvate dehydrogenase deficiency
Liver - ovaries - seminal vesicles
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Keep glutathione reduced so it can detoxify free radicals and peroxides
Glucose 6 phosphate dehydrogenase (G6PD)

11. Giving folate during early pregnancy is important to prevent what birth defects
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Neural tube
Makes RNA primer on which DNA poly III can initiate replication

12. 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
Rb and p53
Elastase - inhibited by alpha1 antitrypsin
African Americans and Asians

13. What happens in zinc def
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Targets the proteins for lysosome
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year

14. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Transmitted only through mother - all offspring of affected females may show signs of disease
Inc insulin - dec cAMP - dec PKA
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Euchromatin

15. What co - factors are required for the pyruvated dehydrogenase complex
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
RRNA
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia

16. What happens in carnitine def
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Inc vit B6
Breaks down acyl - coa to acetyl coa groups in mito
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

17. What does the start codon code for in eukaryotes and prokaryotes
EtOH dehydrogenase and acetaldehyde dehydrogenase
Collagen
HMG- CoA (HMG- CoA to mevalonate
Eu - methionine - pro - formyl - methionine

18. What is the trinucleotide repeat in fragile X
CGG
Glycogen synthase
MRNA - tRNA
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

19. What clotting factors require vit K
Stored ATP - creatine phosphate - anaerobic glycolysis
Carbomoyl phosphate synthetase II
II - VII - IX - X (1972) protein C and S
They yield only acetyl - CoA equivalents

20. What liberates glucose from glucose 6 P
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Malapsorption syndromes like sprue or CF or mineral oil intake
Glucose 6 phosphatase
Facial flushing

21. What apolipoprotein is on LDL
Glucose 6 phosphatase
B100
Oxidative and nonoxidative - no ATP produced or used
Intermediate filaments

22. What apolipoprotiens are on VLDL
B-100 - CII and E
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Schilling test

23. What are the results of unbalanced translocation
40 - 60 - 80
Binds 50S - blocking translocation
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Inc Cl - in sweat

24. What components come together to make S- adenosyl methionine
Neurons
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
ATP and methionine
X linked frame shif mutation

25. What is the function of Zinc
Adds an inorganic phosphate onto substrate without using ATP
Pyruvate - NAD+ - CoA
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Assistance of upper extremities to stand up

26. What is the RDE of fatty acid synthesis
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Arg - lys - his - arg is most basic - has has no charge at body pH
Acetyl - CoA carboxylase (ACC)
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

27. What is the order of severity for the different types of mutations
Makes RNA primer on which DNA poly III can initiate replication
Nonsense > missense > silent
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
B100 and E

28. What does Alports syndrome cause and why
Neuralgia
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Degredation of TG circulating in chylomicrons and VLDLs
PMNs

29. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
SNP
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
B100
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea

30. nucleotide repeat for fredreich's ataxia
GAA
Glycolysis and aerobic respiration
Glucose -6 phosphate
NADH - NADPH - FADH2

31. What substance inside the cell reduces glutatione
NADPH
Cofactor for LPL
Achondroplasia
Niacin - constituent of NAD and NADP - derived from tryptophan

32. What is the TX for PKU
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
OTC has hyperammonemia - orotic aciduira does not
Thymic - parathyroid and cardiac
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

33. What is dominant negative mutation and give an example
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
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Free ribosomes
Inhibits 50S peptidyltransferase

34. What are the fat soluble vitamins and What does their absorption depend on...
Exons
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
FISH
Night blindness - dry skin

35. 1 g of protein or cabrohydrate = ?kcal
Four
Debranching enzyme
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Type II

36. What is Gowers maneuver
17 - 17 letters in von Recklinghausen
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
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
Assistance of upper extremities to stand up

37. What does osteogenesis imperfecta causes and why
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
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
HVA
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

38. What is the results of vit B1 def
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Unmethylated - newly synthesized - HNPCC
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Procollagen - triple helix of 3 alpha collagen chains

39. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
X linked frame shif mutation
Post to neg
Inc glucagon - inc cAMP - inc PKA
P2 +2pq+ = 1

40. What is the amino acid precuros for niacin and serotonin/melatonin
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Tryptophan
Supply sufficient glucose to brain and RBCs and to preserve protein
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

41. What neuroanatomical strutures are injured in wernicke - korsakoff
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
Medial dorsal nucleus of thalamus - mamillary bodies
Phenylalanine hydroxylase

42. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Removes phosphate group from substrate
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
Von gierkes - glucose 6 phosphatase
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

43. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
B-100 - CII and E
2 -4 DNP - aspirin
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

44. What happens at the smooth ER
Site of steroid synthesis and detoxification of drugs and poisons
Type II
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

45. What does a northern blot use as its sample
Disease
RNA
Changed AA (convservative - new AA is similar in chemical structure)
Karyotyping

46. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
OTC has hyperammonemia - orotic aciduira does not
Orotic acid to UMP
Fasting

47. What two cells are particularly rich in RER
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Neural tube
32 - malate aspartate shuttle
Mucus secreting globlet cells and antibody secreting plasma cells

48. what findings are associated with marfans
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
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
Silencers

49. What is uniparental disomy
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes

50. What are Heinz bodies
Adenosine to inosine
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Oxidized hemoglobin precipiated within RBCs
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step