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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. What does apoCII do
Carnitine shuttle - acyl - coa from cyto to mito
Cofactor for LPL
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

2. How does ethanol induce hypoglycemia
Carbomoyl phosphate synthetase I
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
Base + ribose
Stored ATP - creatine phosphate - anaerobic glycolysis

3. pyruvate carboxylase catalyzes what rxn
Acetyl - CoA to malonyl - CoA (2C to 3C)
Pyruvate to oxaloacetate (3C to 4C)
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Microarrays

4. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
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
After citruline
NAD+
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis

5. What is NADPH used for
Anabolic processes as a supply of reducing equivalents
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
The triphosphate bond
Citrate - acetyl coa from mito to cyto

6. How does abetalipoproteinemia present and What is the defect
Glycogen synthase
Early in life - AR - inability to synthesize lipoproteins due to def in apoB100 and B48 - intestinal biopsy shows accumulation within enterocytes due to inability to export absorbed lipid as chylomicrons - failure to thrive - steatorrhea - acanthocyt
VLDL
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins

7. What does degenerate/rundant genetic code refer to...
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Achondroplasia
More than 1 codon may code for the same amino acid
VMA

8. What is the treatment for orotic aciduria
Phenylalanine hydroxylase
Nonsense > missense > silent
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Oral uridine administration

9. What does desmin stain for
Inc insulin - dec cAMP - dec PKA
Inc dicarboxylic acids - dec in glucose and ketones
Muscle
Alpha and beta tubulin - dimers have two GTP bound

10. How do glucagon/epi lead to glycogenolysis
B48 - AIV - CII - E
No
Glycolysis and aerobic respiration
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis

11. What is the RDE of de novo purine synthesis
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Tropoelastin with fibrillin scafolding
Glutamine PRPP amidotransferase
Phenylalanine hydroxylase

12. What fxn does glucokinase serve in the liver
Marfans
Connective tissue
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer

13. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
Inc insulin - dec cAMP - dec PKA
CAG - 4
Antioxidant - protects RBCs and membrances from free radical damage
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

14. What enzyme converts phenylalanine to tyrosin
X linked frame shif mutation
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Phenylalanine hydroxylase

15. What reaction does adenosine deaminase normally catalyze
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Adenosine to inosine
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Consesus sequenec of base pairs

16. What is the TX for CF and What does it do
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
ADPKD
Schilling test

17. What are Heinz bodies
Neuralgia
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Oxidized hemoglobin precipiated within RBCs

18. What does cytokeratin stain for
SnRNPs
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Medial dorsal nucleus of thalamus - mamillary bodies
Epithelial cells

19. What is the structure of elastin
Tropoelastin with fibrillin scafolding
Fasting
Basement membrane or basal lamina
Liver - ovaries - seminal vesicles

20. ADPKD is associated with What additional conditions
Carnitine shuttle - acyl - coa from cyto to mito
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Rotenone - CN- - antimycin A - CO
Liver - ovaries - seminal vesicles

21. What does universal genetic code refer to and What are some exception
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
32 - malate aspartate shuttle
Phosphofructokinase 1

22. What does acetyl - CoA become before becoming palmitate
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
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
GTP
ATP

23. Describe the replication fork
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Phenylethamolamine N methyl transferase
Robertsonian translocation and mosaicism
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

24. What kind of branches do glycogen branches have
Microarrays
Dec DNA - dec lymphos leads to SCID
Alpha 1 -6 and alpha 1 -4
Stored ATP - creatine phosphate - anaerobic glycolysis

25. What enzyme adds Cl - to the H202 to makes bleach
After citruline
Myeloperoxidase
BOne
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

26. Broadly - What can cause fat - soluble vitamin deficiencies
Degredation of TG circulating in chylomicrons and VLDLs
Exercise: inc NAD/NADH - inc ADP - inc Ca
Neg to pos
Malapsorption syndromes like sprue or CF or mineral oil intake

27. What activates the pyruvate dehydrogenase complex
Fructose 1 -6 bisphosphate
Exercise: inc NAD/NADH - inc ADP - inc Ca
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Nine

28. What does biotin def cause
IMP precursor
Dermatitis - alopecia - enteritis
DTMP
By inhibiting formation of the initiation complex and cause misreading of mRNA

29. Who typically has lactase def
African Americans and Asians
Inc Cl - in sweat
CTG
Vit K antagonist

30. What is the source of energy in the fasting state between meals
Avidin
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Tryptophan
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

31. What do B- complex vitamin deficiencies often result in
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Dermatitis - glossitis - and diarrhea
Phenytoin - MTX - and sulfonamides
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle

32. Acetyl - CoA carboxylase catalyzes what rxn
Acetyl - CoA to malonyl - CoA (2C to 3C)
HGPRT - defective purine salvage - excess uric acid production
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
ATP

33. In which state is FBPase -2 active
MRNA - tRNA
Inc vit B6
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Fasting

34. What is the activated carrier for methyl groups
Protective against malaria
SAM
X linked frame shif mutation
Attachment of ubiquitin to defective proteins tag them for breakdown

35. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
X linked frame shif mutation
Alanine
P+q = 1
Glycine

36. delivers hepatic TGs to peripheral tissue - secreted by liver
VLDL
Degradation of TG stored in adipocytes
Zero
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

37. In eukaryotes - What does RNA poly II make
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
BOne
MRNA
CAG - 4

38. What enzyme converts adenine to AMP
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
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
Mutated dystrophin gene - less severe - adolescence
APRT + PRPP

39. Where do you find elastin and What does it do
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Robertsonian translocation and mosaicism
Active secretion in lungs and GI - reabsorbs in skin
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond

40. In what cells do the respiratory burst occur
By inhibiting formation of the initiation complex and cause misreading of mRNA
Carbomoyl phosphate synthetase II
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
PMNs

41. What is NAD+ generally used for
Catabolic processes to carry reducing equivalents away as NADH
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
UGA - UAA and UAG
Lacks glucose 6 phophatase

42. metaphse chromosomes are stained - ordered and numbered according to morphology - size - arm length ratio - banding pattern
Karyotyping
Liver hepatocytes and steroid producing cells of the adrenal cortex
Facial flushing
Isocitrate dehydrogenase

43. How does cytosine become uracil
Liver - also in kidney and gut epithelium
Deamination
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Makes RNA primer on which DNA poly III can initiate replication

44. What CETP do
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
HMP shunt
Mediates chylomicron secretion

45. depression - progressive dementia - choreiform movements - caudate atrophy and dec levels of GABA and ACH in the brain
75 to 90 - cloverleaf
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Huntingtons

46. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
IDL
PCR - denaturation - annealing - elongation
Phosphofructokinase 1
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

47. What are the characteristics of prader willi syndrome How does it occur
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase

48. What is the RDE of glycogen synthesis
Alanine
Glycine - aspartate - glutamine
Glycogen synthase
Phenylethamolamine N methyl transferase

49. How do microtubules grow and collapse
Cartilage - hyaline - vitreous body - nucleus pulposus
Grows slowly - collapses quickly
One
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

50. What is the RDE of TCA cycle
Cytosol
Isocitrate dehydrogenase
More than 1 codon may code for the same amino acid
Malapsorption syndromes like sprue or CF or mineral oil intake