Fatty acid metabolism.pptx assignment pdf

Citric acid is a versatile organic acid found in many fruits, especially citrus fruits like lemons, oranges, limes, and grapefruits. Its chemical formula is C6H8O7, and it's classified as a weak acid. Citric acid has a wide range of applications, from food and beverage production to household cleaning and skincare. In this comprehensive description, I'll delve into its properties, uses, production methods, health effects, and environmental impact.

*1. Properties of Citric Acid:*
Citric acid appears as a white crystalline powder or granules. It's odorless and has a tart, sour taste. It's highly soluble in water, making it easy to incorporate into various products. Citric acid is stable at room temperature but decomposes at higher temperatures, losing its acidic properties. It's a chelating agent, meaning it can bind to metal ions, making it useful in certain industrial processes and household cleaners.

*2. Sources of Citric Acid:*
While citric acid occurs naturally in citrus fruits, it's also produced commercially through microbial fermentation, primarily using strains of the fungus Aspergillus niger. This method allows for large-scale production of citric acid to meet the demand in various industries. Additionally, it can be synthesized chemically, although this method is less common due to higher production costs and environmental concerns.

*3. Uses of Citric Acid:*
*- Food and Beverage Industry:* Citric acid is widely used as a flavoring agent, acidity regulator, and preservative in the food and beverage industry. It enhances the flavor of many products and provides a tart taste in sodas, candies, jams, and preserves. It also acts as a preservative, extending the shelf life of packaged foods and preventing discoloration in fruits and vegetables.
*- Pharmaceutical Industry:* Citric acid is used in pharmaceuticals as a pH regulator, excipient in tablets and capsules, and as a flavoring agent in syrups and liquid medications.
*- Cleaning Products:* Due to its chelating properties, citric acid is used in household cleaning products such as descalers, bathroom cleaners, and dishwashing detergents. It effectively removes mineral deposits and stains without the need for harsh chemicals.
*- Cosmetics and Personal Care:* Citric acid is found in skincare products like exfoliating scrubs, facial peels, and anti-aging creams. It helps to promote skin renewal by gently removing dead skin cells and promoting collagen production.
*- Industrial Applications:* Citric acid is used in various industrial processes, including water softening, metal cleaning, and the production of detergents and surfactants.

*4. Production Methods:*
*- Microbial Fermentation:* This is the most common method for commercial production of citric acid. It involves fermenting glucose or sucrose-containing substrates with strains of Aspergillus niger in large-scale bioreactors. The fungus produces citric acid as a byproduct of its metabolism, which is then extracted and purified.
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1. Lipid catabolism

2. Digestion, Mobilization, and Transport of Fats three sources: Dietary fats, stored , synthesized in one to export in other. H ighly industrialized countries :On average, 40% of the daily energy requirement of humans is supplied by dietary triacylglycerols (recommend no more than 30% ). Triacylglycerols provide more than half the energy requirements of some organs: e.g., liver , heart, and resting skeletal muscle. virtually the sole source of energy in hibernating animals and migrating birds.

3. Dietary Fats Are Absorbed in the Small Intestine bile salts, such as taurocholic acid Lipases….Mono and diacylglycerol and free fatty acids. triacylglycerols and packaged with dietary cholesterol and specific proteins into lipoprotein aggregates called chylomicrons. Apolipoproteins are lipid-binding proteins in the blood , responsible for the transport of triacylglycerols , phospholipids , cholesterol, and cholesteryl esters between organs. Lipoprotein…… VLDL to VHDL

4. chylomicron

5. Mobilization of triacylglycerols stored in adipose tissue.

6. Entry of glycerol into the glycolytic pathway.

7. Fatty Acids Are Activated and Transported into Mitochondria 14 or more carbons carnitine shuttle acyl-CoA synthetases

8. Β Oxidation

9. Oxidation of unsaturated fatty acids

10. Oxidation of polyunsaturated fatty acids

11. Oxidation of propoinyl -Co A

12. Β -Oxidation in other organelles

13. ω oxidation of fatty acids In endoplasmic reticulum of liver and kidney the preferred substrates are fatty acids of 10 or 12 carbon atoms.

14. α oxidation of fatty acids Peroxisome Refsum’s disease , resulting from a genetic defect in phytanoyl -CoA hydroxylase , leads to very high blood levels of phytanic acid A severe neurological problems , including blindness and deafness

15. Lipid Synthesis

16. Fatty acid biosynthesis

17. Cholesterol biosynthesis Cholesterol, like long-chain fatty acids, is made from acetyl-CoA Synthesis takes place in four stages , 1. condensation of three acetate units to form a six-carbon intermediate, mevalonate ; 2. conversion of mevalonate to activated isoprene units; 3. polymerization of six 5-carbon isoprene units to form the 30-carbon linear squalene ; 4. cyclization of squalene to form the four rings of the steroid nucleus, with a further series of changes to produce cholesterol.

18. Brief Summary

19. 1. Synthesis of Mevalonate from Acetate

20. 2. Conversion of Mevalonate to Two Activated Isoprenes

21. 3. Condensation of Six Activated Isoprene Units to Form Squalene

22. 4. Conversion of Squalene to the Four-Ring Steroid Nucleus