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What are some of the distinctive clinical features of Williams syndrome? (FA p93)
Congenital microdeletion of long arm of chromosome 7 (deleted region includes elastin gene)   Elfin facies, mental retardation, Hypercalcemia (increased sensitivity to VIT D), well developed verbal skills. Extreme friendliness with strangers, cardiovascular problems.
What are the acidic amino acids?
Acidic = Asp and Glu (negatively charged at body pH)
Where can you find high concentrations of basic amino acids?   Why are these amino acids found in these areas?
Basic = Arg (most basic), Lys and His; Arg and His are required during periods of growth. Arg and Lys are increased in histones. Which bind negatively charged DNA.
What are the clinical features of hyperammonemia?
Results in excess NH4, which depletes alpha ketoglutarate.   Intox = Tremor, slurring of speech, somnolence, vomiting, cerebral edema, blurring of vision.  
Describe the probe and sample to which the probe binds in the following molecular biology techniques: Southern blot, Northern blot, and Western blot.
Southern blot: A DNA sample is electrophoresed on a gel, DNA probe added binds to complimentary strand.   Northern Blot: same as southern but radioactive DNA probe binding to sample RNA.   Wester blot: sample protein is separated via gel electrophoresis and transferred to a filter. Labeled antibody used to bind to relevant PROTEIN
What are the 3 different eukaryotic RNA polymerases?  What type of RNA does each make?
RNA polymerase I = rRNA RNA polymerase II = mRNA RNA polymerase III = tRNA
What is the rate-limiting enzyme for ketone synthesis?
Ketone synthesis = HMG CoA synthase
for cholesterol synthesis? (FA p99)
HMG CoA reductase
  • glycogen synthesis

Glycogen synthase
  • glycogen breakdown
Glycogen phosphorylase
  • fatty acid synthesis
Acetyl-CoA carboxylase
  • fatty acid oxidation
Carnitine acyltransferase I
What type of collagen is abnormal in patients with Alport’s syndrome?
Type IV collagen.= nephritis and deafness.
What is the composition of a nucleosome?  Which histone ties nucleosomes together?
Nucleosome = condensed chromatin form negatively charged DNA looped twice around positively charged histone octamer (2x H2A, H2B, H3 and H4)   Octamer mainly lysine and arginine (positively charged)   H1 ties nucleosome beads together in a string.
What is the most common urea cycle disorder?  What are the findings with this disorder? (FA p108)
Ornithin transcarbamoylase deficiency (x-linked recessive). Interferes with body’s ability to eliminate ammonia. Evident in first few days of life.   Findings: orotic acid in blood and urine, decreased BUN, symptoms of hyperammonemia and increased glutamine.
What is southwestern blot used to identify?
DNA binding proteins.
What amino acids are necessary for purine synthesis? (FA p74)
Glycine, Aspartate, Glutamine
What are the three symptoms of pellagra?  What are the causes of pellagra? (FA p95)
B3 Deficiency = Dermatitis, Dementia, Diarrhea.
Which lysosomal storage disease fits the following description? (FA p114)
  • cherry red spot on retina
Tay Sachs (hexosaminidase A)
Which lysosomal storage disease fits the following description? (FA p114)
  • corneal clouding + mental retardation

Hurler’s syndrome (alpha-L-iduronidase)  
Which lysosomal storage disease fits the following description?

  • no corneal clouding + mental retardation

Hunter's Syndrome (Iduronate sulfatase)
Which lysosomal storage disease fits the following description? (FA p114)
  • demyelinating disease affects peripheral nerves
Metachromatic leukodystrophy  (arylsulfatase A)
Which lysosomal storage disease fits the following description? (FA p114)

  • crinkled paper cytoplasm

Gaucher's (glucocerbrosidase)
Which lysosomal storage disease fits the following description? (FA p114)
  • sphingomyelin buildup

Niemann-Pick disease (sphingomyelinase)
  • Which lysosomal storage disease fits the following description? (FA p114)   treatment is dialysis
Fabry’s disease (alpha galactosidase A)
Which lysosomal storage disease fits the following description? (FA p114)
  • accumulation of galactocerebroside in the brain
Krabbe’s disease (galactocerebrosidase)
Where would you expect to find type I collagen?  type II collagen?  (FA p84)
Be So Totally Cool, Read Books   Type 1 = Bone, Skin, Tendon, dentin, fascia, cornea late wound repair   Type II = Cartilage, vitreous body, nucleus pulposus.  
What is the main function of vitamin C? (FA p84, FA p97
Hydroxylation of proline and lysine in collagen synthesis,   Also facilitates iron absorption by keeping iron in Fe2+ reduced state (more absorbable)   Necessary for dopamine B-hydroxylase
What enzyme is deficient in alkaptonuria?  What are the manifestations of alkaptonuria? (FA p109)
Deficiency of homogentisic acid oxidase in the degradative pathway of tyrosine. Autosomal recessive. Benign disease.   Dark connective tissue, pigmented sclera, urine turns black on standing. May have arthalagias
What is the difference between variable expression, incomplete penetrance, pleiotropy, and anticipation?  (FA p88)
Variable expression – Nature and severity of phenotype vary from 1 individual to another   Incomplete penetrance – Not all individuals with a mutant genotype show the mutant phenotype   Pleiotropy – 1 gene has > 1 effect on an individual’s phenotype   Anticipation – Severity of disease worsens or age of onset of disease is earlier in succeeding generations
What is the most common vitamin deficiency in the US?  What disease develops when there is a deficiency of this vitamin?  (FA p96)
Folic acid, synthesizes nitrogenous bases in DNA and RNA   Megaloblastic anemia, without neurologic symptoms
Which ketone body imparts a fruity odor to breath during ketoacidosis?  Which ketone body is not detected by a urine test? (FA p115)
In liver fatty acids and amino acids are metabolized to acetoacetate and B-hydroxybutyrate   Acetoacetate = fruity odor   B-hydroxybutyrate (for use in muscle and brain) = not detected in urine tests.
What are the vitamin K clotting factors?  What drug antagonizes vitamin K?  
Factors II, VII, IX, X and protein C and S. Warfarin is vit K antagonist.
Describe the structure of a microtubule.  What are the functions of microtubules?  Which drugs inhibit microtubules? (FA p83)
Polymerized dimers of alpha and beta tubulin. Each dimer has 2 GTP bound. Incorporated into flagella, cilia, mitotic spindles. Grows slowly, collapses quickly
What is the cause of maple syrup urine disease?  What are the clinical features of maple syrup urine disease? (FA p110)
Blocked degradation of branched amino acids (Ile, Leu, Val) due to decreased alpha-ketoacid dehydrogenase.   Causes increased alpha ketoacids in the blood, especially Leu.   Causes severe CNS defects, mental retardation, and death.
What is the difference between kwashiorkor and marasmus? (FA p98)
Kwashiokor – protein malnutrition resulting in skin lesions, edema, liver malfunction. MEAL – Malnutrition, Edema, Anemia, Liver (fatty)   Small child with swollen belly   Marasmus – energy malnutrition resulting in tissue and muscle wasting, loss of subcutaneous fat and variable edema
What is the cause of I-cell disease? (FA p82)
Inherited lysosomal storage disorder; failure of addition of mannose-6-phosphate to lysosome proteins (enzymes are secreted outside the cell instead of being targed to the lysosome.   Coarse facial features, clouded corneas, restricted joint movement. Often fatal in childhood
What are the irreversible enzymes of glycolysis?  What are the irreversible enzymes of gluconeogenesis?  (FA p102, FA p104)
Glycolysis – Hexokinase/glucokinase PFK -1 (rate-limiting step) Pyruvate Kinase   Gluconeogensis – Pyruvate carboxylase In mitochondria Pyruvate -> oxaloacetate PEP carboxykinase In cytosol. Oxaloacetate -> phosphoenolpyruvate Fructose-1,6-bisphoshyatase Fructose 1,6 bisphosphate -> Fructos-6p Glucose-6-phosphatase In ER Glucose-6-P -> glucose   Pathway Produces Fresh Glucose
How can excess ethanol cause hypoglycemia? (FA p98)
Ethanol metab increase NADH/NAD+ ratio in liver, causing diversion of pyruvate to lactate and OAA to malate, thereby inhibiting gluconeogensis and stimulating fatty acid synthesis.   = hypoglycemia and hepatic fatty change
  What are the principle signs and symptoms of Lesch-Nyhan syndrome?  What enzyme is defective in this syndrome, and what is its biochemical role? (FA p111)
Retardation, self mutilation, aggression, hyeruricemia, gout, choreoathetosis.   HGPRT which converts hyposzanthine to IMP and guanine to GMP. = excess uric acid production.
Explain the role of folate and B12 in the formation of DNA (and generation of red blood cells)?
B12 Cofactor for homcysteine methyltransferase and methylmalonyl-CoA mutase   Homocysteine + N-methyl THF -> Methionine + THF   Methylmalonyl-CoA -> Succinyl-CoA   Folate is converted to tetrahydrofolate (THF), a coenzyme for 1- carbon transfer/methylation reactions. Important for synthesis of nitrogenous bases in DNA and RNA.
What is the “key” to initiating sleep?  What is the principle neurotransmitter involved in REM sleep?  What neurotransmitter reduces REM sleep?  How long does it take to achieve REM sleep? (FA p71)
Seroternergic predominance of raphe nucleus is key to initiating sleep.   Principle neurotransmitter is ACh. Takes 90 minutes to reach REM.   NE reduces REM sleep.
What are the functions of the Golgi apparatus? (FA p82)
1. Distributes proteins and lipids from ER to plasma membrane, lysosomes, and secretory vesicles. 2. Modifies N-oligosaccharides on asparagine. 3. Adds O-oligosaccharides to serine and threonine. 4. Addition of mannose-6-phosphate to specific lysosomal rpoteins –Targets the protein to the lysosome. 5. Proteoglycan assembly from core proteins. 6. Sulfation of sugars in proteoglycans and of selected tyrosine on proteins.   COP1 = retrograde COP II antero grade (ER -> Golgi) Clathrin comes from trans Golgi and assists in receptor mediated endocytosis.
What is the difference between a promoter region and an enhancer region on DNA?
Promoter = site where RNA polymerase and multiple other transcription factors bind to DNA upstream from gene locus (AT-rich upstream sequence with TATA and CAAT boxes) If there is a promoter mutation commonly results in dramatic decrease in amount of gene transcribed.   Enhancer region  = Stretch of DNA that alters gene expression by binding transcription factors. Can occur anywhere along a DNA sequence.  
What are the different forms of vitamin D? (FA p97)
  D2 = ergocalciferol – ingested from plants, used as pharmacologic agent. D3 = cholecalciferol – consumed in milk, formed in sun-exposed skin.   25-OH D3 = storage form 1,25-(OH)2D3 (calcitriol) = active form.
What are the complications of cystic fibrosis?  (FA p91)
Plugs lungs, pancreas, and liver ->  recurrent pulmonary infections (pseudomonas and S. aureus), chronic bronchitis, bronchiectasis, pancreatic insufficiency, meconium ileus in newborns.
  • cofactor for various carboxylations
  • converted to a cofactor used in transamination (ALT, AST)
B6 pyridoxine
What is the rate-limiting enzyme for glycolysis? for gluconeogenesis? (FA p99)
Glycolysis = Phosphofructokinase-1 (PFK-1)   Gluconeogensis = Fructose-1,6-bisphosphatase
TCA Cycle
Isocitrate dehydrogenase
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