Obese guy goes on a low carb diet. Where is he getting the majority of his newly synthesized glucose?
Glycerol from fat breakdown contributes to 80% of the newly synthesized glucose in this patient.
What is ochronosis?
Retained homogentisic acid that selectively binds to collagen in connective tissues, tendonsm and cartilage, imparting a blue-black pigmentation most evident in the ears, nose and cheeks.
What is alkaptonuria?
Metabolic disorder chracterized by a deficiency of homogentisic oxidase, leading to accumulation of homogentisic acid.
Accumulates in joints(-> degeneration) and is excreted in the urine(undergoes oxidation = black urine)
What are the 3 hemiacetal reducing dissacharides?
- Maltose (glucose + glucose) a1-4
- Lactose (galactose + glucose) B1-4
- Cellulobiose (glucose) B 1-4
Alpha vs beta in carbohydrates
Alpha = below plane
Beta = above plane
What are characteristics of tuberous slcerosis?
- Autosomal dominant disease characterized by adenoma sebaceum(angiofibromata) and ash-leaf spots.
- Cortical hamartomas present in the brain
- Present with mental retardation and seizures, and are at risk for cardiac rhabdomyomas.
What is the best way to detect viral load?
reverse transcriptase PCR
What is Friedreich ataxia?
- Trinucleotide repeat expansion disorder inherited as recessive.
- In childhood with progressive ataxia and severe dysarthria
- Findings: loss of reflexes, spasticity, extensor plantar responses, and impaired vibration and position sense.
How are peptides read?
N -> C
What are 4 protein structures?
Primary- AA sequence
Secondary - Alpha helix & Beta sheets
Tertiary- Fibrous vs globular
Quaternary- Electrostatic, H bond, hydrophobic
What are the components needed for DNA replication?
- Helicase (unwind)
- Single strand binding protein
- topoisomerase (cuts string)
- DNA polymerase 5-> 3 direction (E - leading strand, delta lagging strand)
Microvesicular steatosis of the liver along with pernicious vomiting, lethargy progressing to coma, and hepatomegaly after the chicken poxs indicates what?
Reye syndrome that occurs after a viral infection.
What does Alpha-1 receptor stimulation lead to?
Gq to stimulate phspholipase C -> increase intracellular calcium and increase protein kinase C.
Also causes vasoconstriction of peripheral blood vessels, pupillary dilation, contraction of sphincters in the GI tract and bladder, and pilomotor smooth muscle contraction.
Also M1, M3, and AT1
Why does tyrosine metabolism need pyroxidine?
To produce Dopamine from L-DOPA via Dopa Decarboxylase
What can be derived from L-tryptophan?
- L tryptophan
- (tryptophan hydroxylase)
- (decarboxylase + pyroxidine)
- (methylation SAM + acetylation)
What enzyme is increased by insulin and catalyzes the rate-limiting step in fatty acid biosynthesis?
What is the energy source for the first 100 seconds?
- Stored ATP and creatine phosphate
- Then glycogen breakdown
Citrate is the negative allosteric regulator of what enzyme in the cytosol?
What does a deficiency in the enzyme y-glutamyl transpeptidase result in?
Mental retardation, seizures and increased plasma and urine levels of glutathione (tripeptide)
Amino acid levels dont rise because there are other alternative means of getting AAs transported.
What are problems related to deficiency in vitamin A?
- Night blindness
- bitots spots
- skin damage
- immune deficiency
What would you get with Wilson's disease?
- Copper accumulation in the liver brain and eyes.
- Brain- caudate nucleus and putamen -> choreoathetosis & tremors
- Kayser-Fleischer rings, seen on slit-lamp examination, because of copper deposition in Descemet's membrane of the cornea.
Why does exercise lead to increased VEGF mRNA synthesis?
Myoglobin oxygen saturation and PO2 decreases are stimulators for VEGF upregulation.
What is the enzyme deficient and the its result with the autosomal recessive disease Von Gierke?
Glycogen storage disease with deficiency in glucose-6-phosphatase or glucose-6-phosphate translocase.
- Failure to thrive
- lactic acidosis
- glycogen accumulation in the liver and kidneys.
What is Hurler Syndrome?
- Alpha-L-iduronidase deficiency -> lysosomal storage disease associated with:
- hepatosplenomegaly, dwarfism, skeletal abnormalities, mental retardation, and corneal clouding.
What is Gaucher disease?
Beta-glucocerebrosidase deficiency -> lysosomal storage disease characterized by:
hepatosplenomegaly and glucocerebroside accumulation in phagocytic cells
What is Tay Sachs Disease
- Hexosaminidase A deficiency -> lysosomal storage disease characterized by:
- progressive neurologic deterioration
- cherry-red spots in the macular region preceding blindness
If branched-chain ketoacid dehydrogenase is the defective enzyme which amino acid should one avoid?
- This is Maple Syrup disease
- Avoid Leucine, isoleucine, and valine
What amino acid should be avoided with a deficiency in the enzyme histidine decarboxylase?
- This is histidinemia
- Avoid Histidine
What amino acid should be avoided in a deficiency of cystathionine B-synthase?
- This homocytinuria
- Avoid methionine
What is the treatment for phenylketonuria?
Restrict phenylalanine and supplment with tyrosine