Biochemistry Flashcards Preview

FirstAID > Biochemistry > Flashcards

Flashcards in Biochemistry Deck (293)
Loading flashcards...
271

aggressive behavior + mild symptoms of Hurler's syndrome (dev'l delay, gargoylism, airway obstruction, hepatosplenomegaly); heparan sulfate and dermatan sulfate accumulation

Hunter's syndrome (XR)

272

Hypoketotic hypoglycemia (+ weakness and hypotonia)

Carnitine deficiency: can't transport LCFAs into mitochondria, so get toxic accumulation in cytoplasm

273

how many kcal from 1 g protein, carb, fat?

1 g protein --> 4 kcal
1 g carb --> 4 kcal
1 g fat --> 9 kcal

274

LCAT = lecithin-cholesterol acyltransferase: what does it do?

takes cholesterol and puts it into HDL particles (catalyzes esterification of cholesterol)

275

CETP = cholesterol ester transfer protein: what does it do?

allows HDL to deposit cholesterol into LDL, etc.. (mediates transfer of cholesterol esters to other lipoprotein particles)

276

Apolipoprotein E

mediates VLDL and chylomicron remanant uptake by liver cells

277

Apolipoprotein A1

activates LCAT (for cholesterol esterification)

278

Apolipoprotein C-11

lipoprotein lipase cofactor (LPL --> degrades TG circulating in chylomicrons and VLDLs)

279

apolipoprotein B-48

mediates chylomicron secretion by the intestine and chylomicron assembly

280

Apolipoprotein B-100

binds LDL receptor (LDL particle uptake by extrahepatic cells)

281

familial dyslipidemia with increased chylomicrons, increased blood TG and cholesterol; pancreatitis, xanthomas...

type 1: hyper-chylomicronemia
-no increase risk for atherosclerosis

282

familial dyslipidemia with increased LDL; atherosclerosis, Achilles xanthomas, corneal arcus; elevated blood cholesterol

type IIa - familial hypercholesterolemia
-aut dominant
-MI by age 20 if homozygous

283

familial dyslipidemia with increased VLDL; increased blood TGS; pancreatitis

type IV - hypertriglyceridemia
-have hepatic overproduction of VLDL

284

deficiencies in apo-B100 and apo-B48; FTT, steatorrhea, acanthocytosis, ataxia, night blindness

abetalipoproteinemia --> can't synthesize lipoproteins b/c no apob100 and apob48
-autosomal recessive
-accumulation within enterocytes because can't export absorbed lipid as chylomicrons

285

facial lesions (adenoma sebaceum), hypopigmented ash-leaf spots, coritcal and retinal hamartomas, seizures, MR, renal cysts, renal angiomyolipomas, cardiac rhabdomyomas, increased incidence of astrocytomas

Tuberous Sclerosis (variable presentations)

286

3 mitochondrial disorders:
-Leber hereditary optic neuropathy
-myotonic epilepsy
-MELA

1) Leber Hereditary optic neuropathy --> bilateral vision loss
2) Myoclonic epilepsy with ragged red fibers --> myoclonus, seizures, myopathy assoc with exercise; irregularly shaped muscle fibers on skeletal muscle biopsy
3) MELA = mitochondrial encephalomyopathy with lactic acidosis and stroke like episodes--> seizures, stroke-like episodes with neuro-deficit, muscle weakness, increased serum lactate post-exercise and at rest

287

Hypoglycemia after prolonged fasting, with inappropriately low levels of ketone bodies: What enzyme is deficient?

Impaired Beta-oxidateion/Degradation of Fatty Acids; Acyl-CoA dehydrogenase deficiency

288

antibodies against collagen type 4?

=anti-glomerular basement membrane antibodies --> Goodpasture's syndrome! (hemoptysis + oliguria)...

289

recurrent nosebleeds, and pink spider-like lesions on oral and nasal mucosa, face, and arms.

Osler-Weber-Rendu syndrome = hereditary hemorrhagic telangiectasia

290

How are sugars attached to nitrogen-containing bases in nucleotides?

N-glycosidic bonds
(between sugars-->hydrogen bonds; between nucleotides-->phosphodiester bonds)

291

Which step in collagen synthesis is impaired in pts with scruvy?

Hydroxylation of specific proline and lysine residues on the pro-alpha collagen

292

How does ethanol metabolism contriute to hypoglycemia?

increases NADH/NAD ratio in liver --> so, causes:
*pyruvate--> lactate
-and-
*OAA--> malate

***So, inhibits gluconeogenesis and stimulates hepatic fatty change
***So, get overproduction of lactate-->acidosis; also overproduction of NADPH-->increased fatty acid synthesis

293

What mechanism allows for the production of more than one protein by one human gene?

Alternative splicing