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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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1. What are the glucogenic essential amino acids
Phenylketones in urine
The triphosphate bond
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Met - val - arg his

2. What is the function of folic acid
Tropoelastin with fibrillin scafolding
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

3. Pts with albinism are at inc risk For what cancer
Base + ribose
Arginine
Skin
Terminal regions - tropocollagen

4. What enzyme converts glucose 1 p to UDP glucose
UDP glucose pyrophosphorylase
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Phenylketones in urine
Cri du chat

5. In eukaryotes - What does RNA poly II make
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
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
MRNA
Liver - also in kidney and gut epithelium

6. What happens on the nonoxidative arm of the HMP shunt and What is the key enzyme and cofactor
Myeloperoxidase
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Avidin
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

7. Name as many x- linked recessive disorders as you can

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8. What are the fat soluble vitamins and What does their absorption depend on...
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
IMP precursor
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

9. How do labile celss grow and regenerate and What are examples
CAG
SnRNPs
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles

10. What are the results of CF on male fertility
CGG
Males are infertile due to bilateral absence of vas deferens
Kidney - ears - eyes
Degradation of TG stored in adipocytes

11. What does apoB100 do
CarTWOlage
RRNA
Essential fructosuria - fructokinase AR
Binds to LDL receptor - mediates VLDL secretion

12. What does desmin stain for
MEN - 2A and 2B with ret gene
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
Muscle
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

13. What does the golgi add to serine and threonine residues
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
O- oligosaccharaides
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Dermatitis - alopecia - enteritis

14. What does a decrease in decrease in NADPH lead to and why
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Avidin
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Initiate chains

15. What can excess vit B3 cause
Facial flushing
Acetly- CoA - CO2 - NADH
One
MRNA

16. What does primase do
Makes RNA primer on which DNA poly III can initiate replication
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
DTMP
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

17. What is the RDE of the HMP shunt
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Rb and p53
Locus heterogeneity - ocular albinism is x- linked recessive
Glucose 6 phosphate dehydrogenase (G6PD)

18. What part of the pre mRNA contains the actual genetic information coding for protein
Exons
Hyperlipidemia
RRNA
SAM

19. Which phase of the HMP shunt is reversible and Which is irreversible
VMA
Hyperlipidemia
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Oxidative is irreversible

20. What does osteogenesis imperfecta causes and why
Inc melt - dec fluidity
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
Alpha 1 -6 and alpha 1 -4
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

21. What enzyme becomes essential in PKU
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Tyrosine
Read from a fixed starting point as a continuous sequence of bases

22. What is the mutation in beckers muscular dystrophy - What is the severity and time of onset
VMA
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Mutated dystrophin gene - less severe - adolescence
FISH

23. What does GFAP stain for
Neuralgia
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
B-100 - CII and E
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

24. What substances induce phosphofructokinase
Phosphorylation - glycosylation - hydroxylation
AMP - fructose 2 -6 BP
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility

25. Why can't muscle produce in gluconeogenesis
Lacks glucose 6 phophatase
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Ribose 5- P to PRPP
Paclitaxel

26. In eukaryotes - What does RNA poly III make
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
TRNA
Antibiotic use or excessive ingestion of raw eggs
Alanine

27. What is the function and name of vit B6
Protective against malaria
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
Biotin
Griseofulvin

28. What does an umabiguous genetic code refer to...
30 - glycerol -3- phosphate shuttle
Alpha 1 -6 and alpha 1 -4
Each codon specifies only 1 amino acid
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse

29. How is Lesch Neyhan inherited
Sucrose = glucose + fructose - lactose = glucose + galactose
Marasmus - muscle wasting
X- linked recessive
High output cardiac failure - dilated cardiomyopathy - edema

30. How do fluoroquinolones work
Inhibit DNA gyrase specific for prokaryotic topoisomerase
After day 1
Mebendazole/thiabendazole
F16BP

31. What enzyme converts adenine to AMP
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Bind 30s subunit preventing attachment of aminoacyl - tRNA
APRT + PRPP
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

32. What is axonemal dynein
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Phenytoin - MTX - and sulfonamides
MEN - 2A and 2B with ret gene

33. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
LDL
Glucose 6 phosphatase
Exercise: inc NAD/NADH - inc ADP - inc Ca
Hereditary spherocytosis

34. What does Citrate Is Krebs starting substrate for making oxaloacetate
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
LDL
CGG
Heterochromatin = HighlyCondensed

35. characterize mitochondrial inheritance
Abnormal protein folding - degradation before reaching cell surface
Transmitted only through mother - all offspring of affected females may show signs of disease
RNA
Unwinds DNA template at replcation fork

36. What is the rate limiting enzyme in cholesterol synthesis
AR
Locus heterogeneity - ocular albinism is x- linked recessive
Alpha 1 -6 and alpha 1 -4
HMG- CoA (HMG- CoA to mevalonate

37. What stretch of DNA that alters gene expression by binding of transcription factors
Modifies N- oligosaccharides
Paclitaxel
30 - 50 - 70
Enhancers

38. What is the source of energy in the fasting state between meals
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
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
CGG

39. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

40. What catacholamine step is SAM required for
Conversion of NE to epi
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
AR
B100 and E

41. What tissue samples are used for karyotyping
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Blood - bone marrown - amniotic fluid - placental tissue
Breaks down acyl - coa to acetyl coa groups in mito
Modifies N- oligosaccharides

42. Where is fructose 1 -6 bisphosphatase found and What does it do
DTMP
Fasting
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Exons

43. What is the fxn of vit K
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Avidin
Protein
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

44. What is RNAi used for
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Wrinkles and acne
DsRNA promotes degradation of target mRNA knocking down gene expression
Binds 50S - blocking translocation

45. What are the findings in Down's syndrome
P2 +2pq+ = 1
Actin and myosin
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
NF2 on chromosome 22

46. What are cyclins
Mucus secreting globlet cells and antibody secreting plasma cells
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
F16BP

47. What step begins the urea cycle and What is the enzyme needed - Where does it happen
1 -25 OH2 D3 = calcitriol
Marfans
Orotate precursor - with PRPP added later
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

48. What is Gowers maneuver
High output cardiac failure - dilated cardiomyopathy - edema
Lysine and arginine
African Americans and Asians
Assistance of upper extremities to stand up

49. How many rings do purines have
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
NADH - NADPH - FADH2
2 rings
Mutated dystrophin gene - less severe - adolescence

50. trinucleotide repeat for huntingtons
CAG
Reads usual codon but inserts wrong AA
Asp and Glu
2 -4 DNP - aspirin