The transportation of fatty acid and triglycerides.docx

**UNIVERSITY OF JUBA** **SCHOOL OF COMMUNITY STUDIES AND RURAL DEVELOPMENT** **DEPARTMENT OF COMMUNITY STUDIES** **(FOOD AND NUTRITION SCIENCE)** **FOURTH YEAR** **SEMESTER 7** **COURSE: FOOD BIOCHEMISTRY** **PREPARED BY:** **S/N** **NAMES** **INDEX NUMBER** ---------...

**UNIVERSITY OF JUBA** **SCHOOL OF COMMUNITY STUDIES AND RURAL DEVELOPMENT** **DEPARTMENT OF COMMUNITY STUDIES** **(FOOD AND NUTRITION SCIENCE)** **FOURTH YEAR** **SEMESTER 7** **COURSE: FOOD BIOCHEMISTRY** **PREPARED BY:** **S/N** **NAMES** **INDEX NUMBER** --------- --------------------------- ------------------ **1** **GANYA SAVERIO ITTO** **19-CRD-252** **2** **EMMANUEL PETER AJANG** **17-CRD-115** **3** **EZEKIEL DUT AROL** **19-CRD-249** **4** **GABRIEL WEK AKOT** **19-CRD-250** **5** **EMMANUEL WOJA CHARLES** **19-CRD-247** **SUBMITTED TO MR LEMI SAMUEL** **DATE OF PRESENTATION 23/JULY/2024** **TRANSPORT OF FATTY ACIDS, TRIGLYCERIDES AND RELEASE OF ENERGY** **Fatty Acids** Fatty acids are long chains of hydrocarbon molecules with a carboxyl group (-COOH) at one end. They are a type of lipid and are key components of fats and oils in both plants and animals. Fatty acids are classified based on the number of double bonds in their hydrocarbon chain. **Transport of Fatty Acids** The transportation of fatty acids within the body involves several key steps and mechanisms. 1. **Release from Adipose Tissue** Fatty acids are stored in adipose tissue as triglycerides. When energy is needed, hormone-sensitive lipase breaks down triglycerides into free fatty acids and glycerol. 2. **Transport in Blood** Free fatty acids are released into the bloodstream. Because they are not water-soluble, they bind to albumin, a protein in the blood, for transport. 3. **Uptake by Cells** Cells take up free fatty acids through specific transport proteins on their membranes, such as fatty acid translocase (FAT/CD36) and fatty acid binding proteins (FABPs). 4. **Transport into Mitochondria** Inside the cell, fatty acids are activated to form fatty acyl-CoA by the enzyme acyl-CoA synthetase. The fatty acyl-CoA is then transported into the mitochondria for beta oxidation. This transport requires the carnitine shuttle, involving carnitine palmitoyltransferase I (CPT I), carnitine-acylcarnitine translocase (CACT), and carnitine palmitoyltransferase II (CPT II). 5. **Beta Oxidation** Within the mitochondria, fatty acids undergo beta oxidation, a process that breaks them down into acetyl-CoA units. Acetyl-CoA can then enter the citric acid cycle (Krebs cycle) to produce ATP, the energy currency of the cell. 6. **Energy Production** The ATP produced through the citric acid cycle and the electron transport chain is used by the cell for various functions. **TRIGLYCERIDES** Triglycerides are a type of lipid found in blood and are the most common types of fat in the body. They are composed of one molecule and glycerol bound to three fatty acid chains. Triglycerides are formed when the body coverts any calories it doesn't need to use right away into fat and stores them in fat cells. **Transport of Triglycerides** The transportation of triglycerides in the body involves several key steps and components: 1. **Absorption and Packaging** **Digestion;** Triglycerides from dietary fats are broken down into monoglycerides and free fatty acids by pancreatic lipases in the small intestine. **Absorption;** These breakdown products are absorbed by enterocytes (intestinal cells) and re-esterified to form triglycerides. **Chylomicron Formation;** Triglycerides are packaged into lipoprotein particles called chylomicrons along with cholesterol, phospholipids, and proteins (apolipoproteins). 2. **Transport via Lymphatic System and Bloodstream** **Lymphatic Transport;** Chylomicrons enter the lymphatic system and are transported to the bloodstream via the thoracic duct. **Bloodstream;** Once in the bloodstream, chylomicrons circulate and deliver triglycerides to various tissues. 3. **Uptake by Tissues** **Lipoprotein Lipase Action;** An enzyme called lipoprotein lipase, found on the endothelial surface of capillaries in tissues such as adipose tissue and muscle, breaks down the triglycerides in chylomicrons into free fatty acids and glycerol. **Cellular Uptake;** Free fatty acids are taken up by the cells for energy production or storage, while glycerol returns to the liver. 4. **Liver Processing** **Chylomicron Remnants;** after delivering triglycerides, the chylomicrons become chylomicron remnants, which are taken up by the liver. **Very-Low-Density Lipoproteins** (**VLDL) Formation;** in the liver, triglycerides can be re-packaged into very-low-density lipoproteins (VLDL) along with cholesterol and proteins. 5. **Very-Low-Density Lipoproteins** (**VLDL) Transport** **Release into Bloodstream;** VLDL particles are released into the bloodstream where they transport triglycerides to peripheral tissues. **Lipoprotein Lipase Action;** Similar to chylomicrons, very-low-density lipoproteins (VLDL) particles are acted upon by lipoprotein lipase, releasing free fatty acids for uptake by tissues. **IDL and LDL Formation;** as triglycerides are removed, very-low-density lipoproteins (VLDL) particles become intermediate-density lipoproteins (IDL) and eventually low-density lipoproteins (LDL), which primarily transport cholesterol. 6. **Storage and Utilization** **Adipose Tissue Storage;** in adipose tissue, free fatty acids can be re-esterified into triglycerides for storage. **Muscle Utilization;** in muscle tissue, free fatty acids can be oxidized for energy production. **RELEASE OF ENERGY FROM TRIGLYCERIDES AND FATTY ACID** The release of energy from triglycerides and fatty acids involves several biochemical processes: 1. **Lipolysis** Triglycerides stored in adipose (fat) tissue are broken down into glycerol and free fatty acids through a process called lipolysis. This process is catalyzed by enzymes such as hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL). 2. **Transport** Free fatty acids are released into the bloodstream and transported to various tissues, particularly muscle and liver cells. They are carried in the blood by binding to the protein albumin. 3. **Fatty Acid Activation** Inside cells, free fatty acids are activated by coenzyme A (CoA) to form acyl-CoA, a process that requires ATP. This activation occurs in the cytoplasm. 4. **Beta Oxidation** Activated fatty acids (acyl-CoA) are transported into the mitochondria, where beta-oxidation takes place. Beta-oxidation is a series of enzymatic reactions that break down the fatty acid chain into two-carbon units of acetyl-CoA. Each cycle of beta-oxidation produces acetyl-CoA, NADH, and FADH2. 5. **Citric Acid Cycle (Krebs Cycle)** Acetyl-CoA produced from beta-oxidation enters the citric acid cycle. In the citric acid cycle, acetyl-CoA is further oxidized, producing additional NADH and FADH2, as well as ATP and carbon dioxide. 6. **Electron Transport Chain (ETC) and Oxidative Phosphorylation** NADH and FADH2 generated from beta-oxidation and the citric acid cycle donate electrons to the electron transport chain in the inner mitochondrial membrane. As electrons move through the ETC, a proton gradient is created, driving the synthesis of ATP through oxidative phosphorylation. **REFERENCES** 1. Achim Lass, Robert Zimmermann, Guenter Haemmerle, Monika Riederer, Gabriele Schoiswohl, Martina Schweiger, Petra Kienesberger, Juliane G. Strauss, Gregor Gorkiewicz and Rudolf Zechner (206) Adipose triglyceride lipase-mediated lipolysisof cellular fat stores is activated by CGI-58 and defective in Chanarin-Dorfman Syndrome 2. AK. Dutta-Roy (2000) Cellular uptake of long-chain fatty acids: role of membrane-associated fatty-acid-binding: transport proteins 3. Andressa Bolsoni-Lopes, Maria Isabel C. Alonso-Vale (2010) Lipolysis and lipases in white adipose tissue 4. James A. Hamilton (1998) Fatty acid transport: difficult or easy? 5. Kenneth R. Feingold (2022) Lipid and Lipoprotein Metabolism 6. Qiburi He1,Yuhao Chen, Zhigang Wang, Hu He, Peng Yu1*,*(2023) Cellular Uptake, Metabolism and Sensing of Long-Chain Fatty Acids 7. Richard H. Barnes, Elmer S. Miller, and George.O Burr (1941) The Absorption and Transport of Fatty Acids across the Intestinal Mucosa"