Test your basic knowledge |

Biochemistry

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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. Type III collagen
Sucrose = glucose + fructose - lactose = glucose + galactose
Liver - ovaries - seminal vesicles
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

2. What are the two possible causes of albinism
Histidine
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Orotic acid to UMP
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

3. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Inc melt - dec fluidity
Only processed RNA
No
2pq

4. What does a defective Cl channel do
Glutamine PRPP amidotransferase
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
TRNA
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

5. What does glycosylation of pro alpha chian yield and What is the structure
Glucose 6 phosphatase
Peroxide
Procollagen - triple helix of 3 alpha collagen chains
Thymic - parathyroid and cardiac

6. What does the mutation in the gene cause in protein synthesis
Abnormal protein folding - degradation before reaching cell surface
Carbomoyl phosphate synthetase I
RRNA
Modifies N- oligosaccharides

7. cytoskeletal elements associated with cilia - flagella - mitotic spindle - neurones and centrioles
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Reads usual codon but inserts wrong AA
Microtubules
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints

8. What enzyme adds Cl - to the H202 to makes bleach
Myeloperoxidase
Avidin
EtOH dehydrogenase and acetaldehyde dehydrogenase
LDL

9. How does patients present with ADPKD
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
ATP and methionine
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Flank pain - hematuria - HTN - progressive renal failure

10. Which are the acidic amino acids
Asp and Glu
Inc vit B6
Avidin
Base + ribose + phosphate (3' -5') phosphodiester bond

11. Where is glucose 6 phosphatase found and What does it do
In ER - glucose 6- P to glucose
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
ATP and methionine
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

12. What are the characteristics of angelmans syndrome and How does it occur
Silencers
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
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
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

13. What is the defectin IV - hypertriglyceridemia
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Tryptophan
Coenzyme A - lipoamide
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

14. What is the RDE of de novo purine synthesis
Mediates chylomicron secretion
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Orotate precursor - with PRPP added later
Glutamine PRPP amidotransferase

15. What two enzymes are involved in EtOH metabolism
Protein kinase A
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Fibrofatty replacement of muscle - cardiac myopathy
EtOH dehydrogenase and acetaldehyde dehydrogenase

16. What happens at the smooth ER
Site of steroid synthesis and detoxification of drugs and poisons
Phenylalanine hydroxylase
FAP
1 kind with multiple subunits

17. What is the energy source for translocation
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Tryosine hydroxylase
Attachment of ubiquitin to defective proteins tag them for breakdown
GTP

18. What step of uric acid synthesis does xanthine oxidase catalyze
Hypoxanthine to xanthing and xanthine to uric acid
NAD+
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

19. In which state is PFK-2 active
Wrinkles and acne
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Fed
Alpha 1 -6 and alpha 1 -4

20. I g fat = ? Kcal
Oral uridine administration
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Nine
Alpha1 antitrypsin

21. What is the result of vit B5 def
Proton gradient
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Dermatitis - enteritis - alopecia - adrenal insuff
UGA - UAA and UAG

22. Why enzyme breaks down elastin and what enzyme inhibits it
Elastase - inhibited by alpha1 antitrypsin
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

23. What two proteins make up microtubules and how are they arranged
Alpha and beta tubulin - dimers have two GTP bound
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
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
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

24. What is heteroplasmy
Only processed RNA
Orotic acid to UMP
Von Gierke's - Pompe - Cori - McArdle
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

25. How does chloramphenicol work
Inhibits 50S peptidyltransferase
Assistance of upper extremities to stand up
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Consesus sequenec of base pairs

26. congenital microdeletion of long arm of chromosoe 7 with findings of elfin facies - mental retardation - hypercalcemia - well developed verbal skills - extreme friendliness with strangers - cardiovascular problems
Collagen
Acetyl - CoA carboxylase (ACC)
2 rings
Williams syndrome

27. What enzyme results in classic galactosemia and What is the clinical
SnRNPs and other proteins
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Proline and lysine - vit C

28. What is the amino acid precursor for GABA and glutathione
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Fructose 1 -6 bisphosphate
Glutamate

29. Pts with albinism are at inc risk For what cancer
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Skin
CarTWOlage
Same AA - often base change in 3rd position of codon (tRNA wobble)

30. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
Liver hepatocytes and steroid producing cells of the adrenal cortex
Heterochromatin = HighlyCondensed
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

31. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Liver hepatocytes and steroid producing cells of the adrenal cortex
Keep glutathione reduced so it can detoxify free radicals and peroxides
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Hereditary spherocytosis

32. Where is fructose 1 -6 bisphosphatase found and What does it do
Sulfation
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
APKD1 on chromosome 16

33. What apolipoprotein is on LDL
Creat a nick in the helix to relieave supercoils created during replication
B100
Neuralgia
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis

34. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
Hyperlipidemia
Oligomycin
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
Biotin

35. What are Heinz bodies
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
APKD1 on chromosome 16
APRT + PRPP
Oxidized hemoglobin precipiated within RBCs

36. Adenosine deaminase deficiency is an important cause of what immunodeficiency?
Microarrays
Site of steroid synthesis and detoxification of drugs and poisons
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Dec DNA - dec lymphos leads to SCID

37. What converts NE to epi
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
APC on chromosome 5
Phenylethamolamine N methyl transferase
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

38. How is orotic aciduria inherited
Alpha 1 -4 glucosidase
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
AR
ATP and methionine

39. What apolipoprotiens are on VLDL
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
N to C
Removal of N or C termal propeptides from zymogens to generate mature proteins
B-100 - CII and E

40. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Autosomal recessive diseases
Promotor - TATA box - and CAAT box - AT rich
32 - malate aspartate shuttle
Ca/calmodulin in muscle to coordinate with muscle activity

41. What substances are uncouling agents
B100
2 -4 DNP - aspirin
Thymic - parathyroid and cardiac
Nine

42. Which cells are rich in smooth ER
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Glycogen synthase
Nonsense > missense > silent
Liver hepatocytes and steroid producing cells of the adrenal cortex

43. What apolipoproteins are on chylomicrons
Not all individuals with a mutant genotype show the mutant phenotype
B48 - AIV - CII - E
Muscle
Oxidized hemoglobin precipiated within RBCs

44. Which enzyme involved in RNA synthesis does not require a template
Poly A polymerase - signal is AAUAA
VLDL
B100
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive

45. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
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
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Liver hepatocytes and steroid producing cells of the adrenal cortex
Sucrose = glucose + fructose - lactose = glucose + galactose

46. What is the fxn of vit D
Poly A polymerase - signal is AAUAA
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Acetoacetate and beta hydroxybutyrate
Glucose - 2Pi - 2ADP - 2NAD+

47. In a marathon Where does energy come from
Glycogen and FFA oxidation; glucose conserved for final sprinting
Myeloperoxidase
Essential fructosuria - fructokinase AR
P+q = 1

48. What happens with wet beriberi
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Not all individuals with a mutant genotype show the mutant phenotype
High output cardiac failure - dilated cardiomyopathy - edema
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration

49. What is I cell disease
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
Transmitted only through mother - all offspring of affected females may show signs of disease
Post to neg
Paclitaxel

50. What is the Name and function of vit B2
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Unwinds DNA template at replcation fork
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
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)