Lipids Flashcards
transports exogenous dietary fat from intestines to tissues?
Chylomicrons
Transport endogenous triglycerides and cholesterol from the liver to the tissues.
VLDL and LDL
Transport endogenous cholesterol from the tissues to the liver.
HDL
What catalyzes the hydrolysis of TG’s at position 1 and 3 to form free fatty acids and 2-monoacylglycerol.
Pancreatic lipase-colipase
2 sources of NADPH in the Cytosol?
Malic enzyme and Pentose phosphate pathway
3 comp to fatty acid synthesis
- NADPH which is reducing power
- Malonyl-coa (building block to make fatty acids)
- FAS-1 enzyme
what is the intermediate in triglyceride biosynthesis?
Phosphatidic acid
Where are triglycerides synthesized for excretion?
intestine and liver
What converts the fatty acyl groups into their acylcarnitine analogues?
CPT 1
What transfers the fatty acyl group back to Coa?
CPT 2
The final round of B-oxidation of FA’s yields _____ and ______
Acetyl coa and propionyl CoA which is converted to succinylcholine CoA
is the first intermediate in the biosynthesis of palmitate from acetyl CoA.
Melonyl CoA
What inhibits CPT1 and entry of fatty acids into the mitochondria
Malonyl CoA
What is the first ketone body to be synthesized that is also an intermediate in the biosynthesis of cholesterol ?
Acetoacetate
What is the urea cycle enzyme that is the regulated rate limiting step?
CPS1 - Carbamoyl phosphate synthetase 1
___ is caused by an inherited defect in DBAAT
Cystinuria
Na+- dependent or proton dependent cotransporters are?
Specific amino acid transporters
Na+- independent transporter of neutral amino acids are?
L-amino acid transporter
High urine concentration of what AA’s are found in Cystinuria?
Lysine
Arginine
Cysteine
Ornitine
What are the precursors of heme?
Glycine and succinylcholine CoA
What are the biosynthetic precursors of poryphyrins called?
Porphyrinogens
___ diseass caused by an inherited defect in NAAT
Hartnup disease
What is the key regulator of the urea cycle?
N-acetylglutamate (NAG)
Mitochondrial NAG synthase makes NAG from ____ and ____
Glutamate and acetlyCoa
inducible enzyme expressed in response to an inflammatory stimuli. Mediates pain, redness, and swelling of inflammation
COX 2
What is the rate limiting step in keto genesis?
HMG-coA synthase
Which Glut crosses BBB?
Glut 1
3 precursors to gluconeogenesis?
Glycerol, lactic acid, amino acids (usually serine)
How do you DX type 1 DM?
Fasting Blood glucose > 126 mg/Dl
HGA1C > 6.5 mg/Dl
Name 3 sign and symptoms of Metabolic syndrome?
Insulin resistance
Hyperinsulinemia
Dyslipidemia
HTN
Rate limiting step in de novo cholesterol biosynthesis
HMG-COA reductase
3 ways HMG-CoA reductase can be regulated
- Phosphorylation/ dephospho rylation
- SREBP- mediated transcription
- Proteosomal degradation
what is the enzyme that phosphorylates ACC and HMGcoA reductase
AMPK
What is the intermediate that is the precursor of dolichol and coenzyme Q synthesis?
Farnesyl pyrophosphate
What are the 2 nitrogen sources in the urea cycle?
Carbomyl phosphate and Aspartate
What is the allosteric activator of CPS-1 in urea cycle?
NAG
What is the rate limiting step in heme biosynthesis?
ALA synthesis
ALAS1 in heme biosynthesis is inhibited by?
Heme
Alas 2 in heme biosynthesis is inhibited by ?
Iron
What is the precursor of serotonin?
Tryptophan
What is the precursor of dopamine and norepinephrine ?
Tyrosine
Lesch-Nyhan syndrome is an X-linked genetic disorder associated with a deficiency of HGPT that leads to?
Excessive production of uric acid (Gout)
In biosynthesis of Pyrimidines, the first reaction is the synthesis of CARBOMYL PHOSPHATE which is catalyzed by ??
Cytosolic CPS 2
In pyrimidine biosynthesis, CPS 2 is inhibited by ____ and activated by _____ ?
Inhibited by UTP
Activated by PRPP
dTMP is synthesized by methylation of dUMP catalyzed by?
Thymidylate synthase
What is the enzyme that inhibits FduMP (potent anti tumor agent)
thymidulate synthase
What is the enzyme that these drugs inhibit ( Methotrexate, aminopterin, trimethoprim)
Dihydrofolate reductase
Most common form of congenital adrenal hyperplasias ( genetic diseases affected adrenal glands)?
21- alpha hydroxylase
What are the precursors of purine and pyrimidine synthesis?
CO2, PRPP, glutamine, aspartic acid
3 ketones produced in keto genesis?
Acetoacetate
Acetone
B - Hydroxybutyrate