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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 does fomepizole do
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Vit K antagonist
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma

2. Pts with albinism are at inc risk For what cancer
Skin
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Inhibit DNA gyrase specific for prokaryotic topoisomerase
PCR - denaturation - annealing - elongation

3. What does cytokeratin stain for
Epithelial cells
Hypoglycemia
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Transfers methyl units

4. Where is vit B12 found
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Targets the proteins for lysosome

5. What enzyme converts phenylalanine to tyrosin
Inc glucagon - inc cAMP - inc PKA
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
B6
Phenylalanine hydroxylase

6. What happens in elongation of protein synthesis

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7. What is a silent mutation
Same AA - often base change in 3rd position of codon (tRNA wobble)
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
G6PD
Scrutinizes - hydrolyzes the bond

8. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
RNA
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Mutated dystrophin gene - less severe - adolescence

9. What two cells are particularly rich in RER
Mucus secreting globlet cells and antibody secreting plasma cells
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

10. How do cardia glycosides work
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Isocitrate dehydrogenase
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
B6

11. What are the products for glycolysis
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Phenylalanine
Kidney - ears - eyes
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O

12. How do tetracyclines work
Lysine and leucine
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Bind 30s subunit preventing attachment of aminoacyl - tRNA

13. What are the results of pancreatic insuff in CF
Malabsorption and steatorrhea (ADEK)
Familial hypercholesterolemia - hyperlipidemia type IIA
Activates LCAT
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15

14. What happens in a B12 def
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Cofactor for LPL
Neurons

15. How do aminoglycosides work
Phosphorylation - glycosylation - hydroxylation
IDL
Polyneuritis - symmetrical muscle wasting
By inhibiting formation of the initiation complex and cause misreading of mRNA

16. What does apoE do
ATP hyrdolysis couple to energetically unfavorable rxns
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Mediates extra remnant take up
Inhibit DNA gyrase specific for prokaryotic topoisomerase

17. What does SAM do
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
Liver hepatocytes and steroid producing cells of the adrenal cortex
Transfers methyl units

18. What are the fat soluble vitamins and What does their absorption depend on...
B12 and folate
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)
SnRNPs
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

19. What is the target of the 3' hydroxyl attack
RER
The triphosphate bond
Creat a nick in the helix to relieave supercoils created during replication
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints

20. What part of the pre mRNA contains the actual genetic information coding for protein
After citruline
Exons
Methionine encode by only 1 codon (AUG)
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

21. Which enzyme involved in RNA synthesis does not require a template
Poly A polymerase - signal is AAUAA
HMG- CoA (HMG- CoA to mevalonate
Vincritsine/vinblastine
Oxidizes substrate

22. What is the function and name of vit B6
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
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Lysine and arginine
Schilling test

23. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
LDL
Conversion of NE to epi

24. What 3 syndromes are associated with vit B1 def
ATP - citrate
Wernicke - korsakoff - dry and wet beriberi
Neg to pos
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis

25. What is dominant negative mutation and give an example
1 ring
After citruline
Grows slowly - collapses quickly
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

26. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
No
Inc melt - dec fluidity
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

27. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Ribose 5- P to PRPP
Euchromatin
Wrinkles and acne
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

28. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
LDL
Von gierkes - glucose 6 phosphatase
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization

29. How does ouabain work
Liver - ovaries - seminal vesicles
Inhibits the Na/K pump by binding the K side
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Biotin

30. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
AR
Terminal regions - tropocollagen
Oxidative and nonoxidative - no ATP produced or used
Conversion of NE to epi

31. What is the activated carrier for 1 carbon units
Phenylalanine
Carbomoyl phosphate synthetase I
Neimann - pick - sphingomyelinase - sphingomyelin - AR
THFs

32. characterize mitochondrial inheritance
Von Gierke's - Pompe - Cori - McArdle
Transmitted only through mother - all offspring of affected females may show signs of disease
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Scrutinizes - hydrolyzes the bond

33. Which anti breast cancer drugs work on micortubules
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
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
Foliage - small reserve in liver - eat green leaves
Paclitaxel

34. Which are the basic amino acids
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Mebendazole/thiabendazole
Arg - lys - his - arg is most basic - has has no charge at body pH
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

35. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
HDL
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

36. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Hereditary spherocytosis
Achondroplasia
Ile - phe - thr - trp

37. What happens with wet beriberi
Neuralgia
Neither of 2 alleles is dominant - blood groups
High output cardiac failure - dilated cardiomyopathy - edema
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

38. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
Hereditary spherocytosis
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
CGG
Phosphofructokinase 1

39. What is made fir rNucleotides or deoxyrNucleotides and what enzyme is necessary to convert one to the next
Basement membrane or basal lamina
Makes RNA primer on which DNA poly III can initiate replication
Adenosine to inosine
Ribos first then deoxyribos with ribonucleotide reductase

40. What does pancreatic lipase do
Adds an inorganic phosphate onto substrate without using ATP
Degredation of dietary TG in small intestine
NADPH
AR

41. What does desmin stain for
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Each codon specifies only 1 amino acid
Degredation of dietary TG in small intestine
Muscle

42. What tissues have only aldose reductase
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
AR
Protein kinase A
Schwann cells - lens - retina - kidneys

43. What is the wernicke - korsakoff clinical picture
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Active secretion in lungs and GI - reabsorbs in skin

44. What causes biotin def
X- linked recessive
Antibiotic use or excessive ingestion of raw eggs
Oligomycin
Ribose 5- P to PRPP

45. What are CDKs
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
G6PD
Cyclin dependent kinases;constitutive and inactive
Chronic granulomatous disease - no respiatory burst - no formatino of ROS

46. What is the prevalence of an X- linked recessive disease in males and in females
Eu - methionine - pro - formyl - methionine
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
75 to 90 - cloverleaf
Q -

47. What enzymes metabolize fatty acids and amino acids
Four
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Glycolysis and aerobic respiration
Acetoacetate and beta hydroxybutyrate

48. Leysh - Nyhan syndrome is a defect in which enzyme and What are the biochemical results
9+2 arrangement of microtubules
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
HGPRT - defective purine salvage - excess uric acid production
N to C

49. Describe the location and fxn of the Na/K ATPase
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
9+2 arrangement of microtubules
Accelearted muscle breakdown
1 ring

50. What causes Hartnup's disease
Glycogenolysis to form glucose
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Males are infertile due to bilateral absence of vas deferens
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma