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211

Carinitine deficiency?

Carnitine shuttle is required to move LCFA's into mitochondria to be broken down. W/o carnitine, accumulated LCFA's --> cardiomyopathy, myopathy, encephelopathy, fasting hypoglycemia (carnitine palmitoyltransferases I or II)

212

Ketogenesis

Only occurs in mitochondria of liver cells with lots of acetyl-CoA present. Acetoacetate and 3-hydroxybutyrate can be used peripherally. Acetone, cannot, and leaves via lungs (fruity odor)

213

Kcal per protein, carb, fat?

4,4,9. (Area code in Mexico; 449. And 9 is fat).

214

How much time does it take to deplete glycogen?

1 day

215

Starvation days 1-3:

Hepatic glycogenolysis, adipose release of FFA, muscle and liver use FFA, hepatic gluconeogenesis

216

Starvation >3days

Adipose stores mostly. Ketone bodies dominate brain energy source. Afterwards, vital protein degradation accelerates.

217

Main purpose of Chlyomicrons, VLDL, LDL, HDLs

Chylos take dietary lipid to tissues. VLDL's deliver hepatic TG's to peripherals. LDL delivers hepatic cholesterol to peripheral tissues (receptor-mediated endocytosis). HDL takes excess tissue cholesterol back to liver.

218

What enzyme removes supercoils?

Topoisomerase II

219

Fetal hemoglobin is made up of what subunits?

2alpha, 2GAMMA;

220

Different hemoglobins?

a2b2 = HbA1; a2d2 = HbA2; a2g2 = HbF

221

How does NE get to Epi?

NE + SAM -Phenylethanolamine-N-methyltransferase(PNMT)-> Epi + S-adenosylhomocysteine

222

The Five Great cofactors are needed for what 3 enzymes?

Pyruvate dehydrogenase, alpha-ketoacid dehydrogenase (Maple), alpha-ketoglutarate dehydrogenase (TCA). Thiamine, lipoic acid, CoA, FAD, NAD+

223

What part of ribosome binds to Shine-Dalgarno sequence of mRNA?

16S rRNA of 30S ribosomal subunit (prokaryotic); You Shine when you're 16.

224

Where do all the electron acceptors come from in the Krebs?

NADH produced by isocitrate dehydrogenase, a-KG dehydrogenase, and malate dehydrogenase. FADH2 produced by succinate dehydrogenase. GTP produced by succinyl CoA synthetase.

225

Lead overdose?

Affinity for sulfhydryl groups leading to inhibition ALA-dehydrase and Ferrochetolase -> dec. heme synthesis. Microcytic anemia (2/2 inhibited delta-ALA dehydrates and reduced Fe into heme), Basophilic stippling (abl aggregation of ribosomes), colicky abdominal pain, constipation, BLUISH pigment at gum tooth, wrist drop/foot drop. 10ug/dL Tx = EDTA or dimercaprol

226

Cyanide poisoning?

Rapidly cutaneous flushing, tachypnea, HA, tachycardia, n/v, confusion. Severe lactic acidosis. Mech - binds cytochrome a-a3, stopping oxidative phosphorylation. Tx = nitrites. Induce formation of methemoglobin, which sequesters cyanide. Sodium thiosulfate can also bind.

227

Heme synthesis overview

Fe2+ and protoporphyrin IX -(ferrochelatase)-> Heme...requires mitochondria. Rate-limiting step is Gly + Succinyl CoA -(ALA synthase)-> aminolevulinic acid. ALA synthase is activated by alcohol, barbiturates, and hypoxia. Mostly synthesized in hepatocytes and erythrocytes, which lose their ability when they lose their mit. Lead affects ferrochelatase and ALA DEhydratase.

228

Poryphyria

Photosensitivity is key feature. Pink-tinted urine that darkens 2/2 porphobilinogen secretion (intermediate). Chronic porphyria due to def. of uroporphyrin decarboxylase. Acute porphyria often due to liver (excessive expression of ALA synthase.

229

GPCR characteristics

SEVEN transmembrane regions. Alpha-GDP -> Alpha-GTP---> alpha dissociates w/ beta+gamma -> activates adenylate cyclase or phospholipase C. Phospholipase C - produce IP3 and DAG. DAG -> PKC. IP3 -> inc. intracellular Ca -> elevated PKC.

230

Harnup disease -

Niacin deficiency b/c of loss of dietary tryptophan b/c of defective intestinal and renal tubular absorption. B3 is made from typtophan.

231

lac operon

Reg gene, promoter gene, operator gene, 3 structural genes called z, y a. Beta-galactosidase, permease, repressor protein. Lactose binds to repressor protein --> PREVENT attachment of repressor to operator. Glucose --> decreased cAMP -> decreased expression (b/c high cAMP activates CAP to bind to promoter)

232

Propionyl CoA

Involved with catabolism of Ile, Val, Met, Threonine ("Ill Val Met Three") cholesterol and odd-chain FA's. Converted to methylmalonyl CoA (propionyl CoA carboxylase, biotin, carboxylation), which is then converted to Succinyl CoA (methylmalonyl CoA isomerase, B12, isomerization)

233

Ricin

Potent toxin from castor oil plant that inhibits protein synthesis by cleaving rRNA component of euk. 60S

234

Ketones are metabolized by what tissues?

Brain, skeletal muscle, cardiac muscle, renal cortex. Cells w/o mitochondria can't use ketone bodies. Liver cannot either b/c they lack succinyl CoA-acetoacetate coA transferase

235

Linkage disequilibrium

When a pair of alleles from two loci are inherited together more or less often than would be expected by random chance alone. Not necessarily physical proximity.

236

Role of liver in triglyceride metabolism?

TG's are stored in adipose, metabolized to FA's + glycerol by hormone sensitive lipase. The glycerol is transported to liver where phosphorylated by glycerol kinase. Then converted to DHAP -> glycolysis or gluconeogenesis.

237

Genetic heterogeneity

Mutations in different genes leading to similar phenotypes

238

Variable expresivity

Same genotype, different phenotypic expression. (NOT penetrance)

239

Marfan vs. Ehlers-Danlos syndrome

EDS - hypermobile joints, hyper elastic skin, fragile tissue susceptible to bruising. Marfan - lens dislocation, aortic aneurysms, long and tall, also hypermobile joints

240

Well-known promoter sequences of eukaryotic genes?

TATA box and CAAT box.