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 does a dehydrogenase do
Oxidizes substrate
Core proteins
Hypoglycemia
Tryptophan

2. Where is vit A found in the diet
Liver and leafy veggies
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
UGA - UAA and UAG
Breaks down acyl - coa to acetyl coa groups in mito

3. Describe the structure of cilia
Wernicke - korsakoff - dry and wet beriberi
Cytosol
9+2 arrangement of microtubules
SnRNPs and other proteins

4. Which carbon bears the triphosphate and the energy source for bond formation

5. characterize autosomal recessive inheritance
Adenosine to inosine
1/4 of offspring from 2 carrier parents are affected - often enzyme def - usually only seen in 1 generation - often more sever than AD - presents in childhood
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

6. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
ATP and methionine
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
75 to 90 - cloverleaf

7. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Hyperlipidemia
Von gierkes - glucose 6 phosphatase
Coenzyme A - lipoamide
Accelearted muscle breakdown

8. bilateral acoustic schwannomas - juvenile cataracts
Breaks down acyl - coa to acetyl coa groups in mito
NF2 on chromosome 22
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle
After citruline

9. What substances are uncouling agents
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Cyclin dependent kinases;constitutive and inactive
2 -4 DNP - aspirin
Superoxide dismutase

10. What is the result of vit B5 def
Disease
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Covalent cross - linking by lysyl oxidase to make collagen fibrils

11. What is chediak higashi
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Free ribosomes
Carbomoyl phosphate synthetase II
Skin

12. RNA poly can't proofread - but What can it do
Initiate chains
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Fibrofatty replacement of muscle - cardiac myopathy
Infection - free radicals generated by inflammatory response

13. recurrent pulmonary infxns in CF are due to what organisms
Pseudomonas and s aureus
Glycogen and FFA oxidation; glucose conserved for final sprinting
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
CG- 3 > AT-2 - More CG content - melting point goes up

14. What are Heinz bodies
Arg - lys - his - arg is most basic - has has no charge at body pH
30 - glycerol -3- phosphate shuttle
Oxidized hemoglobin precipiated within RBCs
Lactate

15. What apolipoproteins are on chylomicrons
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
B48 - AIV - CII - E

16. depression - progressive dementia - choreiform movements - caudate atrophy and dec levels of GABA and ACH in the brain
Inc Cl - in sweat
VLDL
Huntingtons
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

17. central and peripheral demyelination with ataxia and dementia
Achondroplasia
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Facial flushing
2pq

18. hepatosplenomegaly - aseptic necrosis of femur - bone crisis - MACS that look like crumpled tissue paper

19. What is the main source of folate
Foliage - small reserve in liver - eat green leaves
Connective tissue
MRNA
Mucus secreting globlet cells and antibody secreting plasma cells

20. Name 5 drugs that interfere with nucleotide synthesis
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
L form
P+q = 1
Carnitine acyltransferase I

21. What happens in zinc def
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Ribose 5- P to PRPP
Wobble

22. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
1 kind with multiple subunits
Blood - bone marrown - amniotic fluid - placental tissue
RER
Semiconservative - continuous and discontinuous strands (okazaki fragments)

23. Gene imprinting implies that How many alleles are active at a single locus
One
Malapsorption syndromes like sprue or CF or mineral oil intake
4 under the floor
Arg - lys - his - arg is most basic - has has no charge at body pH

24. What does the ELISA test for
Achondroplasia
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
40 - 60 - 80
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

25. When are glycogen reserves depleted
Dec DNA - dec lymphos leads to SCID
After day 1
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Muscle

26. Why is G6PD def more common among patients of african decent
Alkaptonuria - may have debiliating arthralgias
Accelearted muscle breakdown
Protective against malaria
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

27. nucleotide repeat for fredreich's ataxia
IMP precursor
Changed AA (convservative - new AA is similar in chemical structure)
GAA
Cytosol - F 1 -6 BP to fructose 6 Phosphate

28. What bone disorder has x linked dominant inheritance
G6PD
No
Attachment of ubiquitin to defective proteins tag them for breakdown
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

29. What enzyme degrades a small amount of glycogen in lysosomes
LCAT (lecithin cholesterol acyltransferase)
Alpha 1 -4 glucosidase
Malabsorption and steatorrhea (ADEK)
HMP shunt

30. congenital deficiency of homogentisic acid oxidase in the degradative pathway of tyrosine to fumarate leading to dark connective tissue - brown pigmented sclera - urine turns black on standing - dz and worst complication
Mucus secreting globlet cells and antibody secreting plasma cells
Alkaptonuria - may have debiliating arthralgias
UDP glucose pyrophosphorylase
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

31. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Autosomal recessive diseases
HMG- CoA (HMG- CoA to mevalonate
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

32. Which RNA poly opens DNA at promotor site
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Liver and leafy veggies
RNA poly II
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)

33. What is the fxn of vit D
Defect in fibrillin
2 rings
Cytosol
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

34. What does commaless - nonoverlapping genetic code refer to...
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
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Read from a fixed starting point as a continuous sequence of bases
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS

35. What is loss of heterozygosity and give an example
Bind 30s subunit preventing attachment of aminoacyl - tRNA
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
RNA poly II
Malapsorption syndromes like sprue or CF or mineral oil intake

36. What does a phosphorylase do
Adds an inorganic phosphate onto substrate without using ATP
Glucose 6 phosphatase
MRNA
Not all individuals with a mutant genotype show the mutant phenotype

37. What are the results of pancreatic insuff in CF
Y shaped region along the DNA template where leading nad lagging strands are synthesized
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Malabsorption and steatorrhea (ADEK)
Conversion of NE to epi

38. what findings are associated with marfans
Liver and leafy veggies
Dopamine beta hydroxylase
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Oxidative is irreversible

39. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Lacks glucose 6 phophatase

40. How do you diagnose CFTR
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Inc Cl - in sweat
LCAT (lecithin cholesterol acyltransferase)
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR

41. What is the RDE of glycogenolysis
NADPH
Glycogen phosphorylase
Exons
Neither of 2 alleles is dominant - blood groups

42. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Base + ribose + phosphate (3' -5') phosphodiester bond
Collagen
Liver - also in kidney and gut epithelium

43. Why can't muscle produce in gluconeogenesis
Lacks glucose 6 phophatase
Oxidative and nonoxidative - no ATP produced or used
In ER - glucose 6- P to glucose
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

44. What does the deletion of the dystrophin gene lead to...
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Alanine
Tryosine hydroxylase
Accelearted muscle breakdown

45. cardiomegaly - systemic findings leading to early death - dz and enzyme

46. Which amino acids are elastin rich in
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Proline and glycine (non glycosylated forms)
Glycolysis and aerobic respiration
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

47. What is the treatment for orotic aciduria
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Thymic - parathyroid and cardiac
Oral uridine administration
IMP precursor

48. What part of the pre mRNA contains the actual genetic information coding for protein
Phenylketones in urine
Protective against malaria
Exons
After day 1

49. What are the fetal screening measures for Down
Neg to pos
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Epithelial cells
Stop codon is recognized by release factor - and completed protein is released from ribosome

50. What regulates whether FBPase -2 or PFK-2 is active
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Protein kinase A
Creat a nick in the helix to relieave supercoils created during replication