Lipid metabolism

Lipid metabolism refers to the processes that involve the intercourse and degradation of lipids.

The types of lipids involved include:

Bile salts
Cholesterols
Eicosanoids
Glycolipids
Ketone bodies
Fatty acids - see also fatty acid metabolism
Phospholipids
Sphingolipids
Steroid - see also steroidogenesis
Triacylglycerols (fats) - see also lipolysis and lipogenesis

External links

Lipid metabolism at the US National Library of Medicine Medical Subject Headings (MeSH)
Ophardt, Charles E. (2003) Lipid Catabolism Summary. Virtual Chembook. Elmhurst College.
King, Michael W. Fatty Acid, Omega-3 and Omega-6 Fatty Acid, Triglyceride, and Phospholipid Synthesis and Metabolism. The Medical Biochemistry Page.
Breaking news and clinical trials about Lipid and Metabolism
in Lipid Metabolism and Sites of Action of Lipid-Modifying Drugs (Not Statins)

General

Aerobic respiration	Glycolysis → Pyruvate Decarboxylation → Citric acid cycle → Oxidative phosphorylation (electron transport chain + ATP synthase)

Anaerobic respiration	Electron acceptors are other than oxygen

Fermentation	Glycolysis → Substrate-level phosphorylation ABE Ethanol Lactic acid

Specific
paths

Protein metabolism

Carbohydrate metabolism
(carbohydrate catabolism
and anabolism)

Human

Glycolysis ⇄ Gluconeogenesis

Glycogenolysis ⇄ Glycogenesis

Pentose phosphate pathway Fructolysis Galactolysis

Glycosylation N-linked O-linked

Nonhuman

Photosynthesis Anoxygenic photosynthesis Chemosynthesis Carbon fixation

Xylose metabolism Radiotrophism

Lipid metabolism
(lipolysis, lipogenesis)

Fatty acid metabolism	Fatty acid degradation (Beta oxidation) Fatty acid synthesis

Other	Steroid metabolism Sphingolipid metabolism Eicosanoid metabolism Ketosis Reverse cholesterol transport

Amino acid

Nucleotide
metabolism

Other

Index of inborn errors of metabolism

Description	Metabolism Enzymes and pathways: citric acid cycle enzymes pentose phosphate intermediates glycoproteins enzymes glycosaminoglycans proteoglycan enzymes phospholipid metabolism cholesterol and steroid intermediates sphingolipids enzymes eicosanoids enzymes amino acid intermediates urea cycle enzymes nucleotide intermediates

Disorders	Citric acid cycle and electron transport chain Glycoprotein Proteoglycan Fatty-acid Phospholipid Cholesterol and steroid Eicosanoid Amino acid Purine-pyrimidine Heme metabolism Symptoms and signs

Treatment	Drugs other

Index of biochemical families

Carbohydrates	Alcohols Glycoproteins Glycosides

Lipids	Eicosanoids Fatty acids intermediates Glycerides Phospholipids Sphingolipids Steroids

Nucleic acids	Constituents intermediates

Proteins	Amino acids intermediates

Other	Tetrapyrroles intermediates

Metabolism: lipid metabolism / fatty acid metabolism, triglyceride and fatty acid enzymes

Synthesis

Malonyl-CoA synthesis	ATP citrate lyase Acetyl-CoA carboxylase

Fatty acid synthesis/ Fatty acid synthase	Beta-ketoacyl-ACP synthase Β-Ketoacyl ACP reductase 3-Hydroxyacyl ACP dehydrase Enoyl ACP reductase

Fatty acid desaturases	Stearoyl-CoA desaturase-1

Triacyl glycerol	Glycerol-3-phosphate dehydrogenase Thiokinase

Degradation

Acyl transport

Beta oxidation

General	Acyl CoA dehydrogenase (ACADL ACADM ACADS ACADVL ACADSB) Enoyl-CoA hydratase MTP: HADH HADHA HADHB Acetyl-CoA C-acyltransferase

Unsaturated	Enoyl CoA isomerase 2,4 Dienoyl-CoA reductase

Odd chain	Propionyl-CoA carboxylase

Other	Hydroxyacyl-Coenzyme A dehydrogenase

To acetyl-CoA

Malonyl-CoA decarboxylase

Aldehydes

Long-chain-aldehyde dehydrogenase

Index of inborn errors of metabolism

Description	Metabolism Enzymes and pathways: citric acid cycle enzymes pentose phosphate intermediates glycoproteins enzymes glycosaminoglycans proteoglycan enzymes phospholipid metabolism cholesterol and steroid intermediates sphingolipids enzymes eicosanoids enzymes amino acid intermediates urea cycle enzymes nucleotide intermediates

Disorders	Citric acid cycle and electron transport chain Glycoprotein Proteoglycan Fatty-acid Phospholipid Cholesterol and steroid Eicosanoid Amino acid Purine-pyrimidine Heme metabolism Symptoms and signs

Treatment	Drugs other

Metabolism: lipid metabolism - eicosanoid metabolism enzymes

Precursor

Phospholipase A2

Prostanoids

Cyclooxygenase
- PTGS1
- PTGS2

PGD2 synthase

PGI2 synthase

TXA synthase

Leukotrienes

5-Lipoxygenase activating protein/Arachidonate 5-lipoxygenase

LTA4 hydrolase (B4 synthesis)

Ungrouped

HPGD

Index of inborn errors of metabolism

Description	Metabolism Enzymes and pathways: citric acid cycle enzymes pentose phosphate intermediates glycoproteins enzymes glycosaminoglycans proteoglycan enzymes phospholipid metabolism cholesterol and steroid intermediates sphingolipids enzymes eicosanoids enzymes amino acid intermediates urea cycle enzymes nucleotide intermediates

Disorders	Citric acid cycle and electron transport chain Glycoprotein Proteoglycan Fatty-acid Phospholipid Cholesterol and steroid Eicosanoid Amino acid Purine-pyrimidine Heme metabolism Symptoms and signs

Treatment	Drugs other

Metabolism, lipid metabolism, glycolipid enzymes

Sphingolipid

To glycosphingolipid	Glycosyltransferase Sulfotransferase

To ceramide	From ganglioside Beta-galactosidase Hexosaminidase A Neuraminidase Glucocerebrosidase From globoside Hexosaminidase B Alpha-galactosidase Beta-galactosidase Glucocerebrosidase From sphingomyelin Sphingomyelin phosphodiesterase Sphingomyelin phosphodiesterase 1 From sulfatide Arylsulfatase A Galactosylceramidase

To sphingosine	Ceramidase ACER1 ACER2 ACER3 ASAH1 ASAH2 ASAH2B ASAH2C

Other	Sphingosine kinase

NCL

Ceramide synthesis

Index of inborn errors of metabolism

Description	Metabolism Enzymes and pathways: citric acid cycle enzymes pentose phosphate intermediates glycoproteins enzymes glycosaminoglycans proteoglycan enzymes phospholipid metabolism cholesterol and steroid intermediates sphingolipids enzymes eicosanoids enzymes amino acid intermediates urea cycle enzymes nucleotide intermediates

Disorders	Citric acid cycle and electron transport chain Glycoprotein Proteoglycan Fatty-acid Phospholipid Cholesterol and steroid Eicosanoid Amino acid Purine-pyrimidine Heme metabolism Symptoms and signs

Treatment	Drugs other

Metabolism: lipid metabolism – ketones/cholesterol synthesis enzymes/steroid metabolism

Mevalonate pathway

To HMG-CoA	Acetyl-Coenzyme A acetyltransferase HMG-CoA synthase (regulated step)

Ketogenesis	HMG-CoA lyase 3-hydroxybutyrate dehydrogenase Thiophorase

To Mevalonic acid	HMG-CoA reductase

To DMAPP	Mevalonate kinase Phosphomevalonate kinase Pyrophosphomevalonate decarboxylase Isopentenyl-diphosphate delta isomerase

Geranyl-	Dimethylallyltranstransferase Geranyl pyrophosphate

To cholesterol

To lanosterol	Farnesyl-diphosphate farnesyltransferase Squalene monooxygenase Lanosterol synthase

7-Dehydrocholesterol path	Lanosterol 14α-demethylase Sterol-C5-desaturase-like 7-Dehydrocholesterol reductase

Desmosterol path	24-dehydrocholesterol reductase

To Bile acids

Steroidogenesis

To pregnenolone

Side-chain cleavage

To corticosteroids

aldosterone: 18-hydroxylase

cortisol/cortisone: 17α-hydroxylase
11β dehydrogenase
- HSD11B1
- HSD11B2

To sex hormones

To androgens	17α-hydroxylase/17,20 lyase 3β dehydrogenase 17β dehydrogenase 5α reductase 1 2

To estrogens	Aromatase

Other/ungrouped

Steroid metabolism: sulfatase
- Steroid sulfatase
sulfotransferase
- SULT1A1
- SULT2A1

Index of inborn errors of metabolism

Description	Metabolism Enzymes and pathways: citric acid cycle enzymes pentose phosphate intermediates glycoproteins enzymes glycosaminoglycans proteoglycan enzymes phospholipid metabolism cholesterol and steroid intermediates sphingolipids enzymes eicosanoids enzymes amino acid intermediates urea cycle enzymes nucleotide intermediates

Disorders	Citric acid cycle and electron transport chain Glycoprotein Proteoglycan Fatty-acid Phospholipid Cholesterol and steroid Eicosanoid Amino acid Purine-pyrimidine Heme metabolism Symptoms and signs

Treatment	Drugs other

Index of hormones

Description	Glands Hormones thyroid intermediates metabolism mineralocorticoids Physiology Development

Disease	Diabetes Congenital Neoplasms and cancer Other Symptoms and signs eponymous

Treatment	Procedures Drugs calcium balance corticosteroids oral hypoglycemics pituitary and hypothalamic thyroid