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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 makes up a nucleoside
Base + ribose
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Griseofulvin
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea

2. What step begins the urea cycle and What is the enzyme needed - Where does it happen
ADPKD
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Hereditary spherocytosis

3. What does CATCH 22 stand for and What causes is...
Karyotyping
Epithelial cells
Neither of 2 alleles is dominant - blood groups
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

4. What causes Down syndrome
FMR1 gene - methylation - associated with chromosomal breakage
Leu - lys
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

5. The pyruvate dehydrogenase complex serves In what reaction: products
Acetly- CoA - CO2 - NADH
II - VII - IX - X (1972) protein C and S
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
1 -25 OH2 D3 = calcitriol

6. What does the passage of electrons result in that when coupled to OXPHOS drives the production of ATP
Pyruvate to oxaloacetate (3C to 4C)
Inc glucagon - inc cAMP - inc PKA
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Proton gradient

7. What is the activated carrier for Co2
X linked frame shif mutation
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
IDL
Biotin

8. What is disulfiram used for
Schilling test
Defect in fibrillin
Phenylethamolamine N methyl transferase
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms

9. How do stable (quiescent) cells grow and regenerate and What are examples
VLDL
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Binds to LDL receptor - mediates VLDL secretion

10. What form of amino acids are found in proteins
Stop codon is recognized by release factor - and completed protein is released from ribosome
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)
Inc Cl - in sweat
L form

11. How is orotic aciduria inherited
AR
Carbomoyl phosphate synthetase I
TTP
ATP

12. When does aspartate enter the urea cycle
OTC has hyperammonemia - orotic aciduira does not
Prevent strands from reannealing
After citruline
Cri du chat

13. What are the results of unbalanced translocation
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

14. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Marfans
Polyneuritis - symmetrical muscle wasting
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Anabolic processes as a supply of reducing equivalents

15. What does the golgi apparatus do on asparagine
Modifies N- oligosaccharides
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Blood - bone marrown - amniotic fluid - placental tissue

16. What do DNA topoisomerases do
Creat a nick in the helix to relieave supercoils created during replication
Inhibits RNA polymerase II - found in death cap mushrooms
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Acetyl - CoA to malonyl - CoA (2C to 3C)

17. What is the hardy weinberg allele prevalence
Q -
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Glycine - aspartate - glutamine
P+q = 1

18. In eukaryotes - What does RNA poly I make
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
RRNA
GTP

19. What is chediak higashi
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Coenzyme A - lipoamide
Oxidizes substrate

20. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Adenosine to inosine
No - its non homologous
Autosomal recessive diseases
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

21. What does a decrease in decrease in NADPH lead to and why
5' of the incoming nucleotide
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Four
Neither of 2 alleles is dominant - blood groups

22. What is the TX for CF and What does it do
Ketone - methyl
Attachment of ubiquitin to defective proteins tag them for breakdown
Makes RNA primer on which DNA poly III can initiate replication
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins

23. What causes Edwards syndrome and What is it
Only processed RNA
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
Liver - ovaries - seminal vesicles
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

24. What does a carboxylase do
Each codon specifies only 1 amino acid
Adds 2 carbon with the help of biotin
Avidin
Targets the proteins for lysosome

25. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
Neuralgia
Heterochromatin = HighlyCondensed
Williams syndrome
Von gierkes - glucose 6 phosphatase

26. What are possilbe presentation for galactokinase def
Acetyl - CoA
RRNA
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Failure to track objects or develop a social smile

27. What enzyme esterifies 2/3 of plasma cholesterol
LCAT (lecithin cholesterol acyltransferase)
Marfans
Oral uridine administration
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

28. Describe the location and fxn of the Na/K ATPase
Defect in fibrillin
Autosomal recessive diseases
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

29. Patients with chronic granulomatous disease are at increased risk of infection From which kind of organisms
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Fasting
One
CGG

30. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
III - joint dislocation - anuerysms - organ rupture

31. What test is used for B12 def
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Binds 50S - blocking translocation
Chylomicrons
Schilling test

32. What makes up a nucleotide

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33. What happens in zinc def
AR
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Marasmus - muscle wasting

34. what happens in acyl coa dehyrdogenase def
Must be both activated and inactivated for cell cycle to progress
NADPH
Inc glucagon - inc cAMP - inc PKA
Inc dicarboxylic acids - dec in glucose and ketones

35. What is the wernicke - korsakoff clinical picture
Protein kinase A
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Palate - facial and cardiac defects

36. In what direction are DNA and RNA synthesized

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37. What clotting factors require vit K
II - VII - IX - X (1972) protein C and S
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
Cofactor for LPL
Not all individuals with a mutant genotype show the mutant phenotype

38. What does arsenic do and What are th results of poisoning
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Asp and Glu
Transfers methyl units

39. What is the defect in I- hyperchylomicronemia
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Grows slowly - collapses quickly
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

40. Which kind of osteogenesis imperfecta is fata in utero or in neonatal period
Degredation of dietary TG in small intestine
Neural tube
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
Type II

41. Which direction does kinesin go
Oxidizes substrate
Neg to pos
Debranching enzyme
ATP

42. In which direction is protein synthesized
N to C
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
HDL

43. in a 100 meter sprint Where does energy come from
B6
Basement membrane or basal lamina
Stored ATP - creatine phosphate - anaerobic glycolysis
Familial hypercholesterolemia - hyperlipidemia type IIA

44. trinucleotide repeat fo myotonic dystrophy
CTG
Changed AA (convservative - new AA is similar in chemical structure)
NAD+
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

45. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Dermatitis - enteritis - alopecia - adrenal insuff
Huntingtons
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
Familial hypercholesterolemia - hyperlipidemia type IIA

46. In what cell is collagen synthesis initiated
Fibroblast
Uses ATP to add high energy phophate group onto substrate
Ribos first then deoxyribos with ribonucleotide reductase
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization

47. What are the two possible causes of albinism
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Tropoelastin with fibrillin scafolding
African Americans and Asians

48. What is the Name and function of vit B1
Glucose 6 phosphatase
Arg - lys - his - arg is most basic - has has no charge at body pH
Deamination
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

49. In a 1000 meter run - Where does energy come from
RNA
Uses ATP to add high energy phophate group onto substrate
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Same as sprint + OXPHOS

50. What enzyme does fructose metabolism bypass to reach glycolysis
PFK - rate limiting enzyme
Degredation of dietary TG in small intestine
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Alpha - ketoglutarate dehydrogenase complex