Produces thermogenin which is an ETC uncoupler (decreases proton gradient) - Produces heat Dinitrophenol (used for weight loss) and aspirin (fever w/ OD) also produce this effect

Biochem Flashcards by Michael Matheney

Phosphofuctokinase-1

RL step in glycolysis

Upregulators: AMP, fructose-2,6-bisphosphae

Downregulators: ATP, citrate

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Fructose-1,6-bisphosphatse

RL step in gluconeogenesis; occurs at same location as PFK-1 in glycolysis

Up: ATP, acetyl-CoA

Down: AMP, fructose-2,6-bisphosphatase

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Glycolysis steps that produce ATP

Phosphoglycerate kinase

Pyruvate kinase

Up: Fructose-1,6-bisphosphate

Down: ATP, alanine

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Phosphofructokinase-2

Forms fructose-2,6-bisphosphate from F6P

-This product upregulates glycolysis

Up: Phosphorylation (caused by glucagon =» increased cAMP =» increased PKA)

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Ketogenic diet

Needed for babies/pts. w/ pyruvate dehydrogenase deficiency; pts. get a buildup of lactate and alanine

Clinical: Neurologic deficits, lactic acidosis, increased alanine

Tx: Increased leucine and lysine in diet (ketogenic AAs) or high fat diet

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Interference w/ Complex IV of the ETC

CN-; CO

-Decreases proton gradient and blocks ATP synthesis

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Brown fat

Produces thermogenin which is an ETC uncoupler (decreases proton gradient)

Produces heat
Dinitrophenol (used for weight loss) and aspirin (fever w/ OD) also produce this effect

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Classic galactosemia

Galactose-1-phosphate uridyltransferase deficiency

Clinical: Failure to thrive, jaundice, hepatomegaly, infantile cataracts, intellectual disability

-Galactokinase deficiency presents as a milder version with only signs being reducing sugar in urine and faint cataracts

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Aldose reductase

Converts glucose to sorbitol

Is a problem in cells with constitutive glucose uptake like retinal cells and the kidney

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Carbamoyl phosphate synthetase I

Converts NH4+ to carbamoyl phosphate

-Reacts with Ornithine in the mitochondria to make citrulline

⭐️Enzyme requires n-acetylglutamate

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Two options for Pyruvate under hypoxic conditions

Converted to lactate or alanine

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Hyperammonemia Tx (3 things)

Rifaximin - decreases colonic ammoniagenic bacteria

Lactulose - traps NH4

Avoid protein in diet

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Increased Orotic acid in urine BUT no Megaloblastic anemia

Ornithine Transcarbomylase deficiency; since Citrulline can’t be formed, carbamoyl phosphate is broken down to orotic acid

Presents in first few days of life as ammonia intoxication

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️Enzyme deficiency in albinism

Tyrosinase

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Musty body Oder

PKU; disorder of aromatic AA metabolism leading to toxic buildup, also possibly due to BH4 deficiency

Clinical: Intellectual disability
Growth retardation
Seizures
Eczema, fair skin

Tx: Avoid Phe in diet (artificial sweeteners), supplement tyrosine

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(+) urinary cyanide-Nitroprusside test

Cystinuria

-Renal PCT inability to reabsorb cysteine, Ornithine, lysine, and arginine (COLA)

Tx: urinary alkalinization, Acetazolamide, hydration

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Glucose-6-phosphatase deficiency

Von-Gierke’s Disease; pts. must avoid fructose and galactose

Clinical: Severe fasting hypoglycemia, increased glycogen, increased lactic acid, increased uric acid, increase triglycerides, hepatomegaly

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Lysosomal a-1,4-glucosidase deficiency

“Acid maltase”

Pompe disease

Clinical: Cardiomegaly, hypertrophic cardiomyopathy, exercise intolerance

*AT RISK FOR EARLY DEATH

a-1,6-glucosidase deficiency

Cori Disease; gluconeogenesis intact but pts. can’t debranch glycogen

Clinical: Mild hypoglycemia, mild hepatomegaly, mild uric acidemia, normal lactic acid

Glycogen phosphorylase deficiency

Mcardle’s Disease

Clinical: Exercise intolerance (muscle cramps), myoglobinuria, electrolyte abnormalities

Tx: Vit B6

a-galactosidase A deficiency

Fabry disease

Clinical: Peripheral neuropathy of hands and feet, angiokeratomas, CVD

Increased ceramide trihexoside
XLR inheritance***

Glucocerebrosidase deficiency

Gaucher’s Disease; causes accumulation of glucocerebroside

Clinical: Hepatosplenomegaly, pancytopenia, aseptic necrosis off fthe femur

*Chicken-scratch monos

Sphingomyelinase deficiency

Niemann-Pick Disease; accumulation of sphingomyelin

Clinical: Progressive neurodegeneration, HEPATOSPLENOMEGALY (as opposed to?), foam cells, cherry-red macula

Hexosaminidase A deficiency

Tay-Sach’s Disease; accumulation of GM2 ganglioside

Clinical: Progressive neurodegeneration, cherry-red macula, developmental delay

Galactocerebrocidase deficiency

Krabbe's disease; accumulation of galactocerebroside Clinical: Peripheral neuropathy, developmental delay, optic atrophy, globoid cells

Arylsulfatase A deficiency

Metachromatic leukodystrophy; accumulation of cerebroside sulfate Clinical: Ataxia, dementia (due to demyelination of CNS and PNS)

a-L-iduronidase deficiency

Hurler Syndrome; accumulation of heparan and dermatan sulfate (mucopolysaccharides) Clinical: Developmental delay, gargoylism (coarse facial features), corneal clouding (as opposed to), hepatosplenomegaly

Iduronate sulfatase deficiency

Hunter Syndrome; accumulation of heparan and dermatan sulfate (mucopolysaccharides) Clinical: Mild hurlers + AGGRESSIVENESS *Hunters see clearly and angrily aim for the X" ***XLR inheritance***

Medium-chain acyl-CoA dehydrogenase deficiency

Inability to break down theses FAs; presents as hypoketotic hypoglycemia w/ seizures, coma AVOID FASTING STATES -Similar to carnitine deficiency BUT carnitine is LCFAs (why?)

Lipoprotein Lipase deficiency

Familial hyperchlomicronemia; increased serum chylomicrons, TG, and cholesterol Clinical: Pancreatitis, hepatosplenomegaly, pruritic xanthomas ***Creamy layer in supernatant

Defective LDL receptors

Familial hypercholesterolemia; increased serum LDL and cholesterol Clinical: Accelerated atherosclerosis (MI prior to 20 possible), tendonous xanthomas, corneal arcus (white ring on the periphery of the iris)***

Hepatic overproduction of VLDL

Hypertriglyceridemia; increased serum VLDL and TGLs Clinical: Acute pancreatitis; serum TGL increase AD inheritance*

Chlordiazepoxide

Benzodiazepine

Clomipramine

TCA that can successfully treat OCD in children and adults

TGF-B receptor

Receptor serine/threonine kinase

Long term dialysis complication

Amyloidosis consisting of B2-microglobulin

Increased Rhine hydroxyproline

Indicates increased bone resorption by osteoclasts

Bone repair

1. Ruptured blood vessels form a hematoma bridging the fracture gap 2. (1 week) Soft tissue callus anchors the fracture 3. Osetoblasts deposit immature woven bone - will see irregularly arranged collagen 4. Hyaline cartilage forms at periphery and undergoes endochondral ossification ⭐️"bony callus" 5. Bony callus turns to mature lamellar bone

Areas with no BBB

Median eminence, area postrema, choroid plexus, pineal gland, neurohypophysis

Phase I Reactions

Include oxidation, desulfuration, epoxide formation, hydoxylation Monoamine oxidase can locally hydrolyze some drugs as well

Chenocholic acid/ Cholic acid

First product formed in production of bile salts; these are increased alongside bile salts w/ increased prod.

Hepatic Stellate Cells

Found in the perisinusoidal space (space of Disse) and secrete type I collagen ***Very important in hepatic scarring and portal HTN

General concepts of hepatic zone necrosis

Zone 1 =>> Few toxins, chronic hepatitis Zone 2 =>> Yellow fever Zone 3 =>> Ischemia, Right-sided HF, CCl4, amantin, copper, acetominophen (go to guess)

Microvesicular steatosis causes

Tetracycline, VA