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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. How does insulin inhibit glycogenolysis
Carnitine shuttle - acyl - coa from cyto to mito
Blood - bone marrown - amniotic fluid - placental tissue
Fed
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

2. What are bite cells and when do you see them
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Result from phagocytic removal of heinz bodies my macs - G6PD def
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
1 -25 OH2 D3 = calcitriol

3. What stretch of DNA that alters gene expression by binding of transcription factors
Enhancers
Robertsonian translocation and mosaicism
BOne
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year

4. What enzyme becomes essential in PKU
Adenosine to inosine
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Tyrosine

5. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Inc dicarboxylic acids - dec in glucose and ketones
Von gierkes - glucose 6 phosphatase
O- oligosaccharaides
30 - 50 - 70

6. What happens in hyperammonemia
PFK - rate limiting enzyme
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Neurons
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

7. What is the activated carrier for Co2
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Biotin
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Familial hypercholesterolemia - hyperlipidemia type IIA

8. What do DNA topoisomerases do
Creat a nick in the helix to relieave supercoils created during replication
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Orotate precursor - with PRPP added later

9. What substances directly inhibit electron transport chain
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Keep glutathione reduced so it can detoxify free radicals and peroxides
Familial hypercholesterolemia - hyperlipidemia type IIA
Rotenone - CN- - antimycin A - CO

10. What can excess vit B3 cause
Facial flushing
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Core proteins
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine

11. What are the characteristics of prader willi syndrome How does it occur
Wernicke - korsakoff - dry and wet beriberi
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
LDL
APRT + PRPP

12. What is the amino acid precuros for niacin and serotonin/melatonin
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Tryptophan
Night blindness - dry skin
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

13. What enzymes metabolize fatty acids and amino acids
Core proteins
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Acetoacetate and beta hydroxybutyrate
Facial flushing

14. What shuttle is involved in fatty acid synthesis and What does it move From where to where
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Males are infertile due to bilateral absence of vas deferens
Superoxide dismutase
Citrate - acetyl coa from mito to cyto

15. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Fibrofatty replacement of muscle - cardiac myopathy
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Glutamine PRPP amidotransferase

16. What does a kinase do
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Uses ATP to add high energy phophate group onto substrate
Males are infertile due to bilateral absence of vas deferens
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

17. What are the irreversible enzymes of gluconeogenesis
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Connective tissue
Marasmus - muscle wasting
Cartilage - hyaline - vitreous body - nucleus pulposus

18. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
Adds 2 carbon with the help of biotin
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Microarrays
APKD1 on chromosome 16

19. What is a frame shift
Nissl body - enzyme and NTs
Attachment of ubiquitin to defective proteins tag them for breakdown
HVA
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

20. Which type of chromatin is less condensed - transcriptionally active - sterically accesible
Euchromatin
Neurons
Removes phosphate group from substrate
Von gierkes - glucose 6 phosphatase

21. What is the activated carrier for phosphoryl
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
ATP
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
APKD1 on chromosome 16

22. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
Males are infertile due to bilateral absence of vas deferens
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

23. In prokaryotes - What does makes the different types of RNA
1 kind with multiple subunits
RRNA
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
The triphosphate bond

24. What is regeneration of methionine depedent on...
Result from phagocytic removal of heinz bodies my macs - G6PD def
B12 and folate
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

25. What does apoB48 do
MRNA
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Mediates chylomicron secretion
P2 +2pq+ = 1

26. characterize mitochondrial inheritance
Mitochondria
Transmitted only through mother - all offspring of affected females may show signs of disease
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
5' to 3'

27. nucleotide repeat for fredreich's ataxia
Inhibits 50S peptidyltransferase
GAA
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Adds 2 carbon with the help of biotin

28. What does a phosphatase do
Von gierkes - glucose 6 phosphatase
MEN - 2A and 2B with ret gene
Removes phosphate group from substrate
CG- 3 > AT-2 - More CG content - melting point goes up

29. What converts dopamine to NE
Palate - facial and cardiac defects
Dopamine beta hydroxylase
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

30. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
Covalent cross - linking by lysyl oxidase to make collagen fibrils
APC on chromosome 5
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Epithelial cells

31. What is the RDE of glycogenolysis
Glycogen phosphorylase
IMP precursor
CarTWOlage
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

32. What happens in termination of proteins synthesis
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Stop codon is recognized by release factor - and completed protein is released from ribosome
Mitochondria
Lysine and leucine

33. What is the name is fxn of vit B3
Protein kinase A
Scrutinizes - hydrolyzes the bond
Asp and Glu
Niacin - constituent of NAD and NADP - derived from tryptophan

34. How does warfarin work
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Liver - ovaries - seminal vesicles
Oligomycin
Vit K antagonist

35. What are the findings in Down's syndrome
Transmitted only through mother - all offspring of affected females may show signs of disease
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
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
Eu - methionine - pro - formyl - methionine

36. what disease can cause pellagra
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
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Asp and Glu
ATP and methionine

37. What substances are uncouling agents
Cytosol
2 -4 DNP - aspirin
RRNA
Inhibits the Na/K pump by binding the K side

38. What is trimming
Marfans
Procollagen - triple helix of 3 alpha collagen chains
Poly A polymerase - signal is AAUAA
Removal of N or C termal propeptides from zymogens to generate mature proteins

39. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Silencers
Liver - ovaries - seminal vesicles
Williams syndrome

40. Which anti gout drugs work on microtubules
Cyclin dependent kinases;constitutive and inactive
Acetyl - CoA to malonyl - CoA (2C to 3C)
Particular sequence of DNA where replicatino begins - may be single of multiple
Colchicine

41. what findings are associated with marfans
Failure to track objects or develop a social smile
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Hypoxanthine to xanthing and xanthine to uric acid
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly

42. What is the defect in cystinuria
Changed AA (convservative - new AA is similar in chemical structure)
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Neuralgia
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

43. What test is used for B12 def
Schilling test
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Makes RNA primer on which DNA poly III can initiate replication
ADPKD

44. What substance inside the cell reduces glutatione
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
NADPH

45. What inhibits the carnitine shuttle
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Degredation of TG circulating in chylomicrons and VLDLs
Malonyl coa
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer

46. What does vit C def cause
B100 and E
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Liver - ovaries - seminal vesicles
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response

47. Which amino acids are elastin rich in
Glucose -6 phosphate
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Proline and glycine (non glycosylated forms)
Von Gierke's - Pompe - Cori - McArdle

48. What is used to diagnose muscular dystrophies
Inc CPK and muscle biopsy
Cri du chat
Oral uridine administration
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

49. What substance inside the cells replenishes NADPH
FAP
Anabolic processes as a supply of reducing equivalents
G6PD
Core proteins

50. What causes maple syrup urine disease and What does it lead to...
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
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
25OHD3
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle