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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 does Ehlers Danlos cause and why
Vincritsine/vinblastine
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

2. What are the physical findings of fragile x syndrome
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Modifies N- oligosaccharides
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

3. What 3 steps in RNA processing occur after transcription

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4. What is NAD+ generally used for
Pyruvate - NAD+ - CoA
APRT + PRPP
Catabolic processes to carry reducing equivalents away as NADH
Adenosine to inosine

5. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Not all individuals with a mutant genotype show the mutant phenotype
Inc glucagon - inc cAMP - inc PKA
Cyclin dependent kinases;constitutive and inactive
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

6. What is loss of heterozygosity and give an example
Dermatitis - glossitis - and diarrhea
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
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
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

7. What does the golgi apparatus do on asparagine
Inc insulin - dec cAMP - dec PKA
DNA
Modifies N- oligosaccharides
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

8. Infection with what organism can cause B12 def
AR
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
4 under the floor
Diphyllobothrium latum

9. What is axonemal dynein
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Proton gradient
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

10. What is DNA cloning and How do you do it?
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
GTP
Malonyl coa

11. What is locus heterogeneity and give an example
Creat a nick in the helix to relieave supercoils created during replication
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Niacin - constituent of NAD and NADP - derived from tryptophan
Neimann - pick - sphingomyelinase - sphingomyelin - AR

12. in a 100 meter sprint Where does energy come from
Cofactor for LPL
Dermatitis - alopecia - enteritis
SAM
Stored ATP - creatine phosphate - anaerobic glycolysis

13. What does apoCII do
Methionine encode by only 1 codon (AUG)
Cofactor for LPL
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Peroxide

14. What does apoA 1 do
Von hippel lindau - 3
Free ribosomes
Activates LCAT
Phosphorylation - glycosylation - hydroxylation

15. What is the amino acid precursor for porphyrin and heme
Glycine
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Post to neg
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

16. What converts dopamine to NE
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
Dopamine beta hydroxylase
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
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

17. What is the RDE of de novo pyrimidine synthesis
Conversion of NE to epi
Marfans
Carbomoyl phosphate synthetase II
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

18. What defects characterize DiGeorge syndrome
Thymic - parathyroid and cardiac
MRNA
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

19. What drugs can cause folate def
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Phenytoin - MTX - and sulfonamides
Cartilage - hyaline - vitreous body - nucleus pulposus
9+2 arrangement of microtubules

20. How is orotic aciduria inherited
Neurons
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Result from phagocytic removal of heinz bodies my macs - G6PD def
AR

21. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Intermediate filaments
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

22. What amino acid makes up most of the octamer
Inhibits the Na/K pump by binding the K side
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Lysine and arginine
Antibiotic use or excessive ingestion of raw eggs

23. What happens to oxaloacetate in alcholism
Robertsonian translocation and mosaicism
African Americans and Asians
Phenylalanine hydroxylase
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

24. In eukaryotes - What does RNA poly II make
Fibrofatty replacement of muscle - cardiac myopathy
Hereditary spherocytosis
Pyruvate - NAD+ - CoA
MRNA

25. Give an example of a mitochondrial inherited disease
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
CTG
Adenosine to inosine
Basement membrane or basal lamina

26. What is RNAi used for
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Each codon specifies only 1 amino acid
DsRNA promotes degradation of target mRNA knocking down gene expression
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

27. What does amino acid catabolsim results in the formation of what?
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
CFTR gene - 7 - Phe 508
Essential fructosuria - fructokinase AR
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA

28. Which anti gout drugs work on microtubules
Liver hepatocytes and steroid producing cells of the adrenal cortex
UGA - UAA and UAG
Colchicine
FISH

29. What is the RDE of the HMP shunt
Ca/calmodulin in muscle to coordinate with muscle activity
Hyperlipidemia
Post to neg
Glucose 6 phosphate dehydrogenase (G6PD)

30. In what cell is collagen synthesis initiated
AR
Methionine encode by only 1 codon (AUG)
Acetyl - CoA
Fibroblast

31. What are covalent alterations
Read from a fixed starting point as a continuous sequence of bases
THFs
Phosphorylation - glycosylation - hydroxylation
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

32. What is disulfiram used for
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Glutamate
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms

33. peripheral neuropathy of hands/feet - angiokeratomas - CV/renal disease - dz - def enzyme - acc substrate - inherit
G6PD
Neural tube
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

34. characterize x linked recessive
PMNs
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
Disorder of aromatic amino acid metabolism
Free ribosomes

35. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Familial hypercholesterolemia - hyperlipidemia type IIA
NAD+

36. An inability to convert orotic acid to UMP would be caused by a deficiency either of which two enzymes

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37. What tissues have only aldose reductase
Adenosine to inosine
Schwann cells - lens - retina - kidneys
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)

38. Type III collagen
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Essential fructosuria - fructokinase AR
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Ketone - methyl

39. What does the mutation in the gene cause in protein synthesis
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Abnormal protein folding - degradation before reaching cell surface
Locus heterogeneity - ocular albinism is x- linked recessive
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase

40. A small proportion of Down syndrome is due to What two genetic events
Cre - lox system
Robertsonian translocation and mosaicism
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
ATP and alanine

41. The pyruvate dehydrogenase complex serves In what reaction: products
Acetly- CoA - CO2 - NADH
Glycine - aspartate - glutamine
Hyperlipidemia
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS

42. What does desmin stain for
Muscle
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

43. How do glucagon/epi lead to glycogenolysis
Met - val - arg his
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Cri du chat
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis

44. What is chediak higashi
SNP
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
IDL
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR

45. In a marathon Where does energy come from
Glycogen and FFA oxidation; glucose conserved for final sprinting
Cre - lox system
SAM
Schwann cells - lens - retina - kidneys

46. What does aminoacyl tRNA synthetase do the AA before and after it binds to tRNA - and what happens if it's the wrong the match
Scrutinizes - hydrolyzes the bond
Dec DNA - dec lymphos leads to SCID
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Locus heterogeneity - ocular albinism is x- linked recessive

47. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
Liver - also in kidney and gut epithelium
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Chylomicrons
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

48. Describe the replication fork
Y shaped region along the DNA template where leading nad lagging strands are synthesized
SnRNPs and other proteins
Stored ATP - creatine phosphate - anaerobic glycolysis
Unmethylated - newly synthesized - HNPCC

49. What is a frame shift
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Inhibits RNA polymerase II - found in death cap mushrooms
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

50. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Palate - facial and cardiac defects
Carbomoyl phosphate synthetase II
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase