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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. In eukaryotes - What does RNA poly II make
MRNA
Semiconservative - continuous and discontinuous strands (okazaki fragments)
GAA
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

2. What enzyme converts adenine to AMP
Familial hypercholesterolemia - hyperlipidemia type IIA
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Mebendazole/thiabendazole
APRT + PRPP

3. What produces NADPH
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Defect in fibrillin
Oxidized hemoglobin precipiated within RBCs
HMP shunt

4. What is the trinucleotide repeat in fragile X
DsRNA promotes degradation of target mRNA knocking down gene expression
Hereditary spherocytosis
RRNA
CGG

5. Mediates reverse cholesterol transport from periphery to liver - acts as respository for apoC an apoE - secreted from both liver and small intestine
Ca/calmodulin in muscle to coordinate with muscle activity
HDL
Wobble
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

6. what gene is implicated in fragile X syndrome - and What is the mutation
Targets the proteins for lysosome
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
FMR1 gene - methylation - associated with chromosomal breakage
Inhibits the Na/K pump by binding the K side

7. What is the function of Zinc
N to C
Lysine and arginine
Nissl body - enzyme and NTs
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -

8. What is the energy source after day 3 of starvation
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
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
III - joint dislocation - anuerysms - organ rupture
Glycogen synthase

9. characterize autosomal recessive inheritance
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
Pyruvate - NAD+ - CoA
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
MRNA - tRNA

10. What is trimming
Inc melt - dec fluidity
Proton gradient
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Removal of N or C termal propeptides from zymogens to generate mature proteins

11. What does hepatic TG lipase do
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Unmethylated - newly synthesized - HNPCC
Phenytoin - MTX - and sulfonamides
Degradation of TG remaining in IDL

12. What CETP do
SnRNPs and other proteins
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Activates LCAT
Inhibits RNA polymerase II - found in death cap mushrooms

13. Give an example of a mitochondrial inherited disease
Breaks down acyl - coa to acetyl coa groups in mito
VMA
Dermatitis - glossitis - and diarrhea
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

14. What does the CFTR channel do in the lungs - GI tract and skin
Active secretion in lungs and GI - reabsorbs in skin
Breaks down acyl - coa to acetyl coa groups in mito
Consesus sequenec of base pairs
ATP - citrate

15. What enzyme results in classic galactosemia and What is the clinical
Debranching enzyme
Pyroxidine - converted to pyroxidine phosphate a cofactor used in transamination - decarboxylation - glycogen phosphorylase - cystathionine synthesis and heme synthesis - required for synthesis of niacin and tryptophan
PCR - denaturation - annealing - elongation
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

16. Accurate base pairing is required only in the first two nucleotide positions of an mRNA codon - so conds differeing in the 3rd position may code for the same tRNA/AA due to degenerate genetic code
Wobble
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Degredation of dietary TG in small intestine
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty

17. What is linkage disequilibrium
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Flagella - cilia - mitotic spindles
Diphyllobothrium latum

18. What happens to glycogen in the liver
Kidney - ears - eyes
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Mebendazole/thiabendazole

19. Type IV collagen is an important structural componenet of the BM for which 3 organs
Enhancers
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Basement membrane or basal lamina
Kidney - ears - eyes

20. several distinct syndromes characterized by familial tumors of endocrine glands including pancreas - parathyroid - pituitary - thryoid and adrenal medulla - disorders and gene association
MEN - 2A and 2B with ret gene
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns

21. What does apoCII do
MRNA - tRNA
PMNs
Cofactor for LPL
Leu - lys

22. When does aspartate enter the urea cycle
AMP - fructose 2 -6 BP
After citruline
5' to 3'
RRNA

23. What are the products for glycolysis
Grows slowly - collapses quickly
ATP
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Scrutinizes - hydrolyzes the bond

24. What is the RDE of glycogenolysis
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Glycogen phosphorylase
Robertsonian translocation and mosaicism
Prevent strands from reannealing

25. 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
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Y shaped region along the DNA template where leading nad lagging strands are synthesized
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

26. Which direction does dynein go
Site of steroid synthesis and detoxification of drugs and poisons
Post to neg
Facial flushing
Creat a nick in the helix to relieave supercoils created during replication

27. How is ATP used by the cell
ATP hyrdolysis couple to energetically unfavorable rxns
Thymic - parathyroid and cardiac
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
5' to 3'

28. What does lactase deficiency cause
Type II
UGA - UAA and UAG
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Binds 50S - blocking translocation

29. What is the activated carrier for Co2
Carbomoyl phosphate synthetase II
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Biotin
Neurons

30. What is the RDE of the urea cycle
Inc insulin - dec cAMP - dec PKA
Autosomal recessive diseases
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Carbomoyl phosphate synthetase I

31. Type II collagen
Cartilage - hyaline - vitreous body - nucleus pulposus
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Enhancers

32. What does vit B3 def result in
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Cyclin dependent kinases;constitutive and inactive

33. 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
Basement membrane or basal lamina
Neither of 2 alleles is dominant - blood groups
GAA

34. Which phase of the HMP shunt is reversible and Which is irreversible
MRNA - tRNA
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Oxidative is irreversible
Paclitaxel

35. What causes maple syrup urine disease and What does it lead to...
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
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Histidine
Occurs when cells in the body have different genetic makeup - can be germline mosaic - which may produce a disease that is not carried by parents somatic cells - lyonization - random X inactivation in females

36. What does Alports syndrome cause and why
Acetyl - CoA to malonyl - CoA (2C to 3C)
17 - 17 letters in von Recklinghausen
APKD1 on chromosome 16
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive

37. How do stable (quiescent) cells grow and regenerate and What are examples
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Griseofulvin
P2 +2pq+ = 1

38. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Dopa decarboxylase
Carbomoyl phosphate synthetase II
Inc melt - dec fluidity
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

39. What does a kinase do
EtOH dehydrogenase and acetaldehyde dehydrogenase
Rotenone - CN- - antimycin A - CO
Core proteins
Uses ATP to add high energy phophate group onto substrate

40. What does GFAP stain for
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Inc glucagon - inc cAMP - inc PKA
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Neuralgia

41. What is sorbitol - how and why is it made
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Metanephrine
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Glucose -6 phosphate

42. What are the results of pancreatic insuff in CF
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
Malabsorption and steatorrhea (ADEK)
B100 and E
NAD+

43. What happens with wet beriberi
High output cardiac failure - dilated cardiomyopathy - edema
Glucose 6 phosphatase
Bind 30s subunit preventing attachment of aminoacyl - tRNA
DNA

44. What enzyme adds Cl - to the H202 to makes bleach
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Myeloperoxidase
Glycogen and FFA oxidation; glucose conserved for final sprinting

45. What converts limit dextran to glucose
HDL
P+q = 1
Debranching enzyme
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

46. What metabolic rxns occur in the cytoplasm
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Acetoacetate and beta hydroxybutyrate
IMP precursor
Each codon specifies only 1 amino acid

47. What is the hardy weinberg allele prevalence
P+q = 1
Seals.
Protein kinase A
Dermatitis - alopecia - enteritis

48. in a 100 meter sprint Where does energy come from
Stored ATP - creatine phosphate - anaerobic glycolysis
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
HMG- CoA reductase
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

49. Why is G6PD def more common among patients of african decent
Protective against malaria
L form
Deamination
Kidney - ears - eyes

50. How do aminoglycosides work
Glucose -6 phosphate
40 - 60 - 80
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
By inhibiting formation of the initiation complex and cause misreading of mRNA