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. What are the findings in Down's syndrome
EtOH dehydrogenase and acetaldehyde dehydrogenase
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
Malabsorption and steatorrhea (ADEK)
Fructose 1 -6 bisphosphate

2. What is the RDE of gluconeogenesis
Dopa decarboxylase
Fructose 1 -6 bisphosphate
Euchromatin
32 - malate aspartate shuttle

3. How do glucagon/epi lead to glycogenolysis
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Zero
Actin and myosin
Glycogen synthase

4. What does apoE do
Liver - ovaries - seminal vesicles
Adenosine to inosine
Mediates extra remnant take up
Ile - phe - thr - trp

5. what gene is implicated in fragile X syndrome - and What is the mutation
FMR1 gene - methylation - associated with chromosomal breakage
Degradation of TG stored in adipocytes
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

6. What are the glucogenic essential amino acids
NADH - NADPH - FADH2
RRNA
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Met - val - arg his

7. What causes Down syndrome
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Liver and leafy veggies
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

8. How does chloramphenicol work
Inhibits 50S peptidyltransferase
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Night blindness - dry skin
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

9. What inhibits pyruvate kinase
ATP and alanine
Connective tissue
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

10. What does the primary transcript combine with to form the spliceosome
ADPKD
Inc CPK and muscle biopsy
SnRNPs and other proteins
Arg and his inc in histones Which bind negatively charged DNA

11. What is the energy source for tRNA actication (charging)
Same AA - often base change in 3rd position of codon (tRNA wobble)
Polyneuritis - symmetrical muscle wasting
ATP
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse

12. CF - is AR deletion In what gene On what chromosome resulting in a deletion inf what?
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
CFTR gene - 7 - Phe 508
Creat a nick in the helix to relieave supercoils created during replication
Polycystic liver disease - berry aneurysm - mitral valve prolapse

13. Giving folate during early pregnancy is important to prevent what birth defects
Neural tube
Binds 50S - blocking translocation
MEN - 2A and 2B with ret gene
Tropoelastin with fibrillin scafolding

14. What is the treatment for orotic aciduria
Oral uridine administration
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
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)

15. In a marathon Where does energy come from
Assistance of upper extremities to stand up
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Tryosine hydroxylase
Glycogen and FFA oxidation; glucose conserved for final sprinting

16. What does primase do
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Chylomicrons
FAP
Makes RNA primer on which DNA poly III can initiate replication

17. What enzyme becomes essential in PKU
1 kind with multiple subunits
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
Tyrosine
5' of the incoming nucleotide

18. How many ATP are created by aerobic metobolism of glucose in muslce via what shuttle
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
30 - glycerol -3- phosphate shuttle
EtOH dehydrogenase and acetaldehyde dehydrogenase
Removes phosphate group from substrate

19. What does arsenic do and What are th results of poisoning
Nissl body - enzyme and NTs
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Polyneuritis - symmetrical muscle wasting

20. How do you diagnose CFTR
Inc Cl - in sweat
2 rings
Same AA - often base change in 3rd position of codon (tRNA wobble)
Covalent cross - linking by lysyl oxidase to make collagen fibrils

21. What two cells are particularly rich in RER
Cytosol
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Mucus secreting globlet cells and antibody secreting plasma cells
Von gierkes - glucose 6 phosphatase

22. A small proportion of Down syndrome is due to What two genetic events
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Lysine and leucine
Robertsonian translocation and mosaicism
Inc CPK and muscle biopsy

23. Where is pyruvate carboxylase found - What does it do - What does it require amd What activates it
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Type II
SAM
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA

24. Accurate base pairing is required only in the first two nucleotide positions of an mRNA codon - so conds differeing in the 3rd position may code for the same tRNA/AA due to degenerate genetic code
Neurofibromatosis type 1 (von Recklinghausens disease)
Medial dorsal nucleus of thalamus - mamillary bodies
Wobble
Dopa decarboxylase

25. The pyruvate dehydorgenase complex serves In what reaction: reactants
Stop codon is recognized by release factor - and completed protein is released from ribosome
Pyruvate - NAD+ - CoA
Oxidized hemoglobin precipiated within RBCs
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive

26. What converts limit dextran to glucose
Debranching enzyme
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Activates LCAT

27. Which enzyme involved in RNA synthesis does not require a template
Initiate chains
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Poly A polymerase - signal is AAUAA
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra

28. What is the fxn of vit K
Lariat shape in order and remove intron precisely and join 2 exons
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Niacin - constituent of NAD and NADP - derived from tryptophan
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora

29. What is the Name and function of vit B2
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Seals.
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Rotenone - CN- - antimycin A - CO

30. What is NAD+ generally used for
Disease
Inhibits the Na/K pump by binding the K side
Catabolic processes to carry reducing equivalents away as NADH
Blood - bone marrown - amniotic fluid - placental tissue

31. What can vit B3 be used to treat
Hyperlipidemia
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Catabolic processes to carry reducing equivalents away as NADH
5' of the incoming nucleotide

32. Very Poor Carbohydrate Metabolism stands for 4 of the glycogen storage diseases - What are thy

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

33. What are the mRNA stop codons
Base + ribose + phosphate (3' -5') phosphodiester bond
Covalent cross - linking by lysyl oxidase to make collagen fibrils
UGA - UAA and UAG
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

34. If two alleles are present - but the active allele is deleted - what happens
One
Williams syndrome
Disease
By inhibiting formation of the initiation complex and cause misreading of mRNA

35. What enzyme def can cause emphysema
Accelearted muscle breakdown
Alpha1 antitrypsin
Tuberous sclerosis
MRNA

36. What happens to oxaloacetate in alcholism
NADH - NADPH - FADH2
Blood - bone marrown - amniotic fluid - placental tissue
Arginine
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

37. what findings are associated with marfans
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Lacks glucose 6 phophatase

38. What liberates glucose from glucose 6 P
Glucose 6 phosphatase
AR
Sucrose = glucose + fructose - lactose = glucose + galactose
Wobble

39. What does apoA 1 do
Activates LCAT
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
Carbomoyl phosphate synthetase II
MEN - 2A and 2B with ret gene

40. What enzyme esterifies 2/3 of plasma cholesterol
17 - 17 letters in von Recklinghausen
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
LCAT (lecithin cholesterol acyltransferase)
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

41. What are the 4 assumption of the Hardy Weinberg law
Mebendazole/thiabendazole
Tryptophan
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Von hippel lindau - 3

42. Describe the location and fxn of the Na/K ATPase
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Nissl body - enzyme and NTs
UGA - UAA and UAG

43. trinucleotide repeat for huntingtons
Exercise: inc NAD/NADH - inc ADP - inc Ca
17 - 17 letters in von Recklinghausen
CAG
Phenylethamolamine N methyl transferase

44. What drugs can cause folate def
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Glycogen and FFA oxidation; glucose conserved for final sprinting
THFs
Phenytoin - MTX - and sulfonamides

45. What is the defect in cystinuria
Inc melt - dec fluidity
Alpha1 antitrypsin
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Keep glutathione reduced so it can detoxify free radicals and peroxides

46. What causes B12 def
HMP shunt
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
ATP
Liver and leafy veggies

47. What is the purpose of the HMP shunt
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Accelearted muscle breakdown
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates

48. What produces NADPH
Lysine and arginine
CGG
Enhancers
HMP shunt

49. What is the energy source for translocation
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Acetyl - CoA carboxylase (ACC)
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
GTP

50. What inhibits the carnitine shuttle
Protein kinase A
Malonyl coa
Terminal regions - tropocollagen
Adenosine to inosine