Fatty Acid Metabolism Overview

The process by which fatty acids are synthesized from smaller units, primarily acetyl-CoA.

This enzyme plays a key role in fatty acid synthesis by adding a carbon dioxide molecule to acetyl-CoA, resulting in the formation of malonyl-CoA, a crucial building block in fatty acid synthesis.

This molecule is formed by the addition of a carbon dioxide molecule to acetyl-CoA by Acetyl-CoA Carboxylase and serves as the primary donor of two-carbon units in fatty acid synthesis.

The process by which two long-chain fatty acids are joined to a glycerol molecule, forming a triacylglycerol.

The primary location for the production of triglycerides.

A protein that aids in the transport of fatty acids within cells by attaching them to its sulfhydryl group.

The enzyme complex responsible for catalyzing the synthesis of fatty acids.

A long-chain saturated fatty acid with 16 carbon atoms. This is the most abundant fatty acid produced by the body.

A protein that catalyzes the transfer of an acetyl group from acetyl CoA to the phosphopantetheine-SH group of acyl carrier protein (ACP).

A protein that catalyzes the transfer of a malonyl group from malonyl CoA to the phosphopantetheine-SH group of acyl carrier protein (ACP).

The condensation reaction between an acetyl group and a malonyl group, catalyzed by -ketoacyl-ACP synthase (KS), releases CO2.

A protein that catalyzes the reduction of a -ketoacyl group to a -hydroxyacyl group in fatty acid synthesis. It uses NADPH as the electron donor.

A protein that catalyzes the dehydration of a -hydroxyacyl group to an ,-unsaturated acyl group in fatty acid synthesis.

A protein that catalyzes the reduction of an ,-unsaturated acyl group to a saturated acyl group in fatty acid synthesis. NADPH serves as the electron donor.

The process of transferring the butyryl group from the phosphopantetheine-SH group of ACP to the Cys-SH group of -ketoacyl-ACP synthase (KS).

Fatty acid synthesis requires energy in the form of ATP and reducing power from NADPH.

The process where the body breaks down fatty acids to generate energy. This process is crucial for energy production, especially when glucose supply is low.

Malonyl CoA is a crucial molecule in fatty acid synthesis as it provides two-carbon units for chain elongation. It also acts as a gatekeeper by inhibiting the entry of fatty acids into the mitochondria for beta-oxidation. This reciprocal regulation ensures efficient energy production based on the body's needs.

The fatty acid elongation system allows for the synthesis of longer-chain fatty acids beyond palmitate (16 carbons). This process occurs in the smooth endoplasmic reticulum and mitochondria, utilizing acetyl CoA as the source of two-carbon units.

Desaturation is the process of introducing double bonds into fatty acid chains, converting saturated fatty acids into unsaturated ones. This crucial process occurs primarily in the liver, using fatty acyl CoA desaturase and occurs in the phospholipid molecules like phosphatidylcholine or linked glycerol.

The body stores energy in the form of triglycerides, which are primarily synthesized in the liver and adipocytes. These fats can provide energy for weeks, representing a much larger energy reservoir compared to glycogen.

The process of building fatty acids from smaller units, primarily acetyl-CoA.

The process by which the reducing power of NADH is converted into NADPH, crucial for fatty acid synthesis.

The process of moving acetyl-CoA out of the mitochondria to the cytosol, where fatty acid synthesis takes place.

Palmitoyl-CoA, acting as a negative feedback inhibitor, slows down fatty acid formation.

Citrate plays a role in regulating fatty acid synthesis, acting as an allosteric activator of acetyl-CoA carboxylase.

The synthesis of the simple lipid triglyceride (TG), primarily occurring in the liver and adipose tissue, involves the joining of three fatty acid molecules to a glycerol molecule. This process is essential for energy storage and mobilization.

The formation of triacylglycerol (TG) is a critical step in lipid metabolism. The key intermediate in this process is phosphatidic acid, which is formed by the sequential addition of two fatty acyl chains to glycerol 3-phosphate. The resulting diacylglycerol 3-phosphate is then dephosphorylated to form diacylglycerol, which accepts the third fatty acyl chain to yield TG.

The process involving the transfer of fatty acyl groups from one molecule to another, essential for the formation of triacylglycerols (TG).

Glycerol 3-phosphate, a precursor to triacylglycerol (TG), is produced in the liver and adipocytes from glucose. This process is independent of insulin in the liver, but requires insulin in adipocytes.

Triacylglycerol (TG) is synthesized in the liver, adipocytes, mammary glands, and intestinal mucosal cells. In the liver, TG is also packaged with cholesterol and cholesterol esters into lipoproteins, facilitating transport via the bloodstream.

When an individual consumes carbohydrates or proteins in excess of their energy needs, the surplus is stored as triacylglycerol (TG). The synthesis and breakdown of TG are tightly regulated to ensure that energy reserves are maintained.

The production of membrane phospholipids requires a multi-step process that involves the synthesis of a backbone molecule, the attachment of fatty acids, the addition of a hydrophilic head group, and the potential alteration or exchange of the head group.

Triacylglycerol (TG) biosynthesis is influenced by various hormones, including insulin, glucagon, and adrenal cortical hormones. These hormones play a role in regulating the balance between TG synthesis and degradation.

A phosphodiester linkage connects the polar head of a phospholipid to the glycerol backbone.

All cells except red blood cells (RBCs) can synthesize phospholipids, but triglycerides (TG) are primarily synthesized in the liver, adipose tissue, mammary glands, and intestinal mucosal cells.

Two strategies exist for attaching head groups to phospholipids: 1) Activation of diacylglycerol: CDP-diacylglycerol is formed by a series of steps 2) Activation of head group: CDP-head group is synthesized individually.

The biosynthesis of cardiolipin and phosphatidylinositol (PI) involves a direct transfer of a head group to CDP-diacylglycerol.

This strategy involves a step in which a CDP-head group is formed by attaching a nucleotide (CDP) to the head group. This activated head group then reacts with diacylglycerol to form the phospholipid.

Ceramide is the parent compound of sphingolipids. It's composed of a sphingosine backbone with a fatty acid attached.

Polar lipids (phospholipids, sphingolipids, glycolipids) are synthesized in the smooth endoplasmic reticulum (SER) and then transported to their target cell membranes by Golgi apparatus in the form of vesicles.

Enzymes present in all tissues and pancreatic juice are responsible for the degradation of phospholipids. Phospholipases hydrolyze the ester and phosphodiester bonds of phosphoglycerides.