Dietary Lipid Metabolism

Size: px
Start display at page:

Download "Dietary Lipid Metabolism"

Transcription

1 Dietary Lipid Metabolism Presented by Dr. Mohammad Saadeh The requirements for the Pharmaceutical Biochemistry II Philadelphia University Faculty of pharmacy

2 OVERVIEW Lipids are a heterogeneous group. water-insoluble (hydrophobic) organic molecules (Figure 15.1). Lipidsمهم transported in plasma in association with protein 1. as in lipoprotein particles 2. or on albumin. Lipids are a major source of energy. Provide the hydrophobic barrier that permits partitioning of the aqueous contents of cells and subcellular structures. Some fat-soluble vitamins have regulatory or coenzyme functions, and the prostaglandins and steroid hormones play major roles in the control of the body s homeostasis. Deficiencies or imbalances of lipid metabolism lead to clinical problems such as atherosclerosis and obesity.

3 Digestion, Absorption, Secretion, and Utilization of Dietary Lipids The average daily intake of lipids by U.S. adults is about 81 g, consists from: 90% is normally triacylglycerol (TAG), cholesterol, cholesteryl esters, phospholipids, and free fatty acids. A. Processing of dietary lipid in the stomach The digestion of lipids begins in the stomach. Triacylglycerols (TAGs) from milk contain short- to medium-chain length fatty acids that degraded in the stomach by two acid lipases: 1. lingual lipase and 2. gastric lipase. These are acid stable (ph 4-6) and important in neonates for milk fat digestion. Cystic Fibrosis: Cystic Fibrosis disease (CF): mutation in transmembrane conductance regulator (CFTR) protein that function as chloride channel on epithelium. Defective CFTR results in decreased secretion of chloride and increased reabsorption of sodium and water. In pancreas cause thickened secretion that clog the pancreatic ducts.

4 Digestion, Absorption, Secretion, and Utilization of Dietary Lipids Emulsification of dietary lipid in the small intestine Emulsification of dietary lipids occurs in the duodenum. Emulsification increases the surface area of the hydrophobic lipid droplets so the digestive enzymes can act effectively. The dietary lipids are emulsified in the small intestine using 1.mechanical peristaltic action, 2.and bile salts as detergent.

5 Degradation of dietary lipids by pancreatic enzymes Pancreatic secrete different enzymes 1.pancreatic lipase 2.Colipase 3.cholesteryl ester hydrolase (cholesterol esterase). 4.phospholipase A2. 5.Lysophospholipase

6 Degradation of dietary lipids by pancreatic enzymes 1. Triacylglycerol degradation: pancreatic lipase: 1. pancreatic lipase removes the fatty acids at carbons 1 and 3 from TAG, forming fatty acid and 2-Monoacylglycerol. 2. Pancreatic lipase consist 2%-3% of pancreatic secretion and colipase. Colipase: 1. Colipase binds the lipase at a ratio of 1:1, at the lipid-aqueous interface. 2. Colipase restores activity to lipase in the presence of inhibitory substances like bile acids that bind the micelles. 3. Colipase is activated in the intestine by trypsin.

7 Degradation of dietary lipids by pancreatic enzymes Cholesteryl ester degradation: cholesteryl ester hydrolase (cholesterol esterase): 1. Cholesteryl esters in diet are hydrolyzed by pancreatic cholesteryl ester hydrolase (cholesterol esterase), which produces cholesterol and free fatty acids. 2. cholesterol esterase activity is increased in the presence of bile salts.

8 Degradation of dietary lipids by pancreatic enzymes Phospholipid degradation: phospholipase A2: 1.phospholipase A2 is activated by trypsin and bile salts. 2.Phospholipase A2 removes one fatty acid from carbon 2 of a phospholipid, leaving a lysophospholipid. The remaining fatty acid at carbon 1 can be removed by lysophospholipase. leaving a glycerylphosphoryl base.

9 The digestion of dietary lipids is summarized in Figure 15.2.

10 Control of lipid digestion: lipid digestion controlled by two hormone: 1. cholecystokinin (CCK) and 2. Secretin When increase lipid in small intestine led to the cells in duodenum produce hormone called cholecystokinin (CCK). The effect of CCK: 1. gallbladder release bile salts 2. exocrine cells of the pancreas (release digestive enzymes). 3. Decrease gastric motility and contents. intestinal hormone is Secretin released in low ph, causes: 1. pancreas and liver release a solution rich in bicarbonate that helps neutralize the ph of the intestinal contents.

11 Absorption of lipids by intestinal mucosal cells (enterocytes) mixed micelles: 1. mixed micelles that facilitate the absorption of dietary lipids by intestinal mucosal cells (enterocytes). 2. Consist from 2-monoacylglycerol, cholesterol and free fatty acid with fat-soluble vitamins (A,D,E & K). Absorption of lipids contained in a mixed micelle by an intestinal mucosal cell. [Note: The micelle itself is not taken up.]

12 Resynthesis of triacylglycerol (TAG) and cholesteryl esters lipids absorbed by the enterocytes and the biosynthesis of complex lipids take place in endoplasmic reticulum. 1. fatty acyl-coa synthetase (thiokinase) convert long-chain fatty acids to fatty acyl-coa (need CoA and ATP) monoacylglycerols with fatty acyl-coa convert to TAG, Using two enzymes activities: acyl CoA:monoacylglycerol acyltransferase and acyl CoA:diacylglycerol acyltransferase. 3. Lysophospholipids are reacylated to form phospholipids by a family of acyltransferases. 4. Cholesterol is esterified to a cholesterol ester by acyl CoA:cholesterol acyltransferase.

13 Secretion of lipids from enterocytes: These serum lipoprotein particles such as Chylomicrons are released into the lymph, which carries them to the blood. Chylomicrons consist from two layers: very hydrophobic layer (Triglycerides, cholesterol ester. hydrophilic layer, pospholipids, cholesterol and apolipoprotein B-48. Explain: Chylomicrons consist from two layers. Because this layer stabilizes the particle and increases its solubility, thereby preventing multiple particles from coalescing.

14 Chylomicrons: 1. Chylomicrons synthesized in the intestinal. 2. Chylomicrons transport exogenous triglyceride to other tissues and transport cholesterol and fat soluble vitamin to the liver. Triacylglycerol in Chylomicrons removed by lipoprotein lipase (LPL) which activated by apocii as coenzyme to converted chylomicrons to fatty acids and glycerol. Remnant particles of Chylomicrons removed from the blood by the liver which bind to remnant receptor in liver and recognized by apo E). Fate of glycerol: TAG in intestinal Chylomicrons transporte the TAG to Produce energy, Reesterify to produce TAG Glycerol kinase Glycerol glycerol 3-phosphate Dihydroxyacetone phosphate G3-P enter glycolysis, DHAP enter gluconeogenesis glycolysis gluconeogenesis Fate of Free fatty acids: Fatty acids oxidize in cells to produce energy. Reesterify free fatty acids to produce TAG molecules in Adipocytes.

15 Fatty Acid, Ketone Body, and Triacylglycerol Metabolism Presented by Dr. Mohammad Saadeh The requirements for the Pharmaceutical Biochemistry II Philadelphia University Faculty of pharmacy

16 Overview Free Fatty acids exist in the body (unesterified), and are also found as fatty acyl esters such as triacylglycerols (TAGs). Low levels of free fatty acids occur in all tissues, but substantial amounts found in the plasma, particularly during fasting. Plasma free fatty acids transported on serum by albumin. Free fatty acids oxidized by many tissues particularly liver and muscle to provide energy. Biological membranes contain phospholipids and glycolipids. Fatty acids are attached to certain intra cellular proteins to associate those proteins with membranes. Fatty acids are also precursors of the hormone like prostaglandins. Triacylglycerols (esterified fatty acids ) stored in adipose cells, serve as the major energy.

17 metabolic pathways of fatty acid The figure illustrates the metabolic pathways of fatty acid synthesis, triacylglycerol synthesis and degradation, and their relationship to carbohydrate metabolism.

18 Structure of Fatty Acids A fatty acid consists of a hydrophobic hydrocarbon chain with a terminal carboxyl group (R COOH). A fatty acid has a pka of about 4.8. At physiologic ph, (R COOH) ionizes, becoming R COO, giving the fatty acid its amphipathic nature (having both a hydrophilic and a hydrophobic region). More than 90% of the fatty acids found in plasma as triacylglycerol, cholesteryl esters, and phospholipids contained in circulating lipoprotein particles. Unesterified, free fatty acids are transported in the circulation in association with albumin. Structure of fatty acid lipoprotein particles

19 Saturation of Fatty Acids Saturated fatty acid don't contain C-C double bond. Unsaturated fatty acid, contain two or more C-C double bond. C-C double bond always in the cis rather than in the trans configuration. Double bonds decreases the melting temperature (Tm) of a fatty acid. Increasing the chain length increases the Tm.

20 18:1(9) relative to ω-3 20:5(5,8,11,14,17) relative to ω-3 Essential fatty acids Inability to synthesize in humans, such as: 1. linoleic acid, precursor of ω-6 arachidonic acid, the substrate for prostaglandin synthesis. 2. α-linolenic acid, the precursor of ω-3 fatty acids important for growth and development. Omega (ω)= no of long FA chain no terminal double bond. Omega (ω)= = ω-6 (relative to omega 6) Omega (ω)= = ω-3 (relative to omega 3)

21

22 De novo synthesis of Fatty Acids fatty acids stored as triacylglycerols. fatty acid synthesis occurs in cytosol of liver and lactating mammary glands and, to a lesser extent, in adipose tissue. 1. Production of cytosolic acetyl CoA: Oxidation of Pyruvate produced acetyl CoA The acetyl CoA cannot cross the inner mitochondrial membrane by condensation of oxaloacetate with acetyl CoA by citrate synthase. transferring acetyl CoA (acetate units) from mitochondrial to cytosol. Increase ATP and citrate enhance fatty acid مهم synthesis. مهم See the figure

23 De novo synthesis of Fatty Acids 2. Carboxylation of acetyl CoA to form malonyl CoA: In cytosol, acetyl CoA carboxylated to malonyl CoA by acetyl CoA carboxylase. A. Short regulation of acetyl CoA carboxylase: This Carboxylation is both rate-limiting and regulated step in fatty acid synthesis. Regulation by two way: 1.Allosteric regulation Allosteric activation by citrate. Allosteric inhibition by long-chain fatty acyl CoA. 2. Covalent regulation by phosphorylation for acetyl CoA carboxylase. Inactivated (phosphorylation) of acetyl CoA carboxylase (ACC) by AMP-dependent kinase (AMPK) when increase glucagon and epinephrine. Allosteric regulation

24 De novo synthesis of Fatty Acids B. Long-term regulation of Acetyl CoA Carboxylase (ACC): Diet containing excess calories (particularly high calorie, high-carbohydrate diets) causes an increase in ACC synthesis therefore increase fatty acid synthesis. Note: Insulin enhance fatty acid synthesis. Glucagon and epinephrine inhibit fatty acid synthesis.

25 De novo synthesis of Fatty Acids, see the figure in the next slide Fatty acid synthesis are catalyzed by the multifunctional enzyme, fatty acid synthase, which produces palmitate from acetyl CoA and malonyl CoA. C. Fatty acid synthase: a multifunctional enzyme in eukaryotes x 1. Acetyl CoA bind to the SH group of the ACP. 2. Transferred acetyl CoA residue to thiol group of a cysteine. 3. ACP accepts a three-carbon malonate unit from malonyl CoA. 4. The acetyl group on the cysteine residue condenses with the malonyl group on ACP with release CO The keto group is reduced to an alcohol by NADPH. 6. A molecule of water is removed to introduce a double bond between carbons 2 and 3 (the α- and β-carbons). 7. The double bond is reduced by NADPH. 8. Repeat steps 2-7 five times more. 9. Palmitoyl thioesterase domain release PALMITATE.

26 x

27 De novo synthesis of Fatty Acids D. Major sources of the NADPH required for fatty acid synthesis NADPH produced from: two source of NADPH, 1. The pentose phosphate pathway is supplier of two NADPH for fatty acid synthesis. 2. Cytosolic NADPH produce from oxidize malate to pyruvate by NADP+-dependent malate dehydrogenase (malic enzyme). See the Figure NADPH: nicotinamide adenine dinucleotide phosphate E. Further elongation of fatty acid chains in smooth endoplasmic reticulum. F. Desaturation of fatty acid chains: Enzymes (desaturases) also present in the SER are responsible for desaturating long-chain fatty acids.

28 x Figure 16.11: Interrelationship between glucose metabolism and palmitate synthesis.

29 There are two pathways for glycerol3-phosphate production: 1. glycerol3-phosphate From glycolysis 2. Phosphorylation of glycerol that produce from triacylglycerol hydrolysis that transported through the blood to the liver. Glycolysis Glycerol kinase in liver glycerol phosphate dehydrogenase Glycerol glycerol 3-phosphate dihydroxyacetone phosphate Figure 16.13: Pathways for production of glycerol phosphate in liver and adipose tissue.

30 Synthesis of a molecule of TAG from glycerol phosphate and

31 Mobilization of stored fats and oxidation of fatty acids Release of fatty acids from triacylglycerol: 1. Adipose tiglyceride lipase (ATGL) generate diacylglycerol and fatty acids. 2. Hormone-sensitive lipase (HSL) produce monoacylglycerol and fatty acid. 3. Monoacylglycerol lipase produce fatty acid and glycerol from monoacylglycerol. Regulation of Hormone-sensitive lipase (HSL): Epinephrine increase camp Activate protein kinase A Phosphorylation of Hormone-sensitive lipase (become active).

32 Mobilization of stored fats and oxidation of fatty acids Triacylglycerol glycerol + Fatty acids. Fate of glycerol: glycerol glycerol3-phosphate DHAP DHAP can participate in glycolysis and gluconeogenesis in liver. Fate of fatty acids: Activated to CoA. Oxidized for energy in mitochondria.

33 β-oxidation of fatty acids: Occur in mitochondrial two-carbon fragments are successively removed from the carboxyl end of the fatty acyl CoA, producing acetyl CoA, NADH, and FADH2.

34 β-oxidation of fatty acids: In cytosol, the first step is activation of long chain fatty acid converted to fatty acyl CoA by acyl CoA synthetase and consuming ATP. Inner mitochondria impermeable to fatty acyl-coa, therefor carnitine transported fatty acid, this process is called the carnitine shuttle. From fatty acyl CoA the Carnitine palmitoyl transferase I (CPT-I)produce CoA and acyl carnitine. acyl carnitine transported to mitochondrial matrix with exchange carnitine by carnitine-acylcarnitine translocase. Carnitine palmitoyltransferase II (CPT-II) in inner mitochondrial transfer acyl group from carnitine to CoA and regenerating free carnitine. acyl CoA synthetase

35 Inhibitor of the carnitine shuttle: Synthesis of fatty acids occurs in cytosol. β-oxidation of fatty acids occurs in mitochondrial. Malonyl CoA inhibits CPT-I, preventing the entry of long-chain acyl groups into the mitochondrial matrix. Therefore, palmitate which synthesis in cytosol can not transferred into mitochondria and oxidized. Medium and short Fatty acids (shorter than 12 carbons) can cross the inner mitochondrial membrane without the aid of carnitine or the CPT system. Therefor Malonyl CoA can not inhibit transported medium and short Fatty acids

36 Reactions of β-oxidation: It consists four reactions involving the β-carbon (carbon 3) so shortening the fatty acid chain by two carbons. 4 Steps of β-oxidation for saturated fatty acid: 1. Oxidation, produces FADH 2 by Acyl CoA dehydrogenase. 2. Hydration step, by Enoyl CoA hydratase. 3. Oxidation, produced NADH, by 3-Hydroxyacyl CoA dehydrogenase. 4. Thiolytic cleavage that releases a molecule of acetyl CoA, by β-ketoacyl-coa thilase. These four steps are repeated for saturated fatty acids. No of repeated steps: if even-numbered carbon chains = (n/2) 1 times. Each β-oxidation (4steps, shortening 2 carbon) = FADH 2 + NADH + acetyl CoA FADH2 = 2ATP; NADH= 3ATP; Acetyl CoA= 12 ATP

37 Oxidation of fatty acids with an odd number of carbons The β-oxidation of saturated fatty acid with an odd number proceeds by the same β-oxidation reaction, until the final three carbons are reached. This compound called propionyl CoA. Finally, propionyl CoA converted to Succinyl CoA which can enter the TCA cycle.

38 Oxidation of unsaturated fatty acids: The oxidation of unsaturated fatty acids provides less energy than saturated fatty acids. Unsaturated fatty acids bypass the first β-oxidation reaction, therefore unsaturated fatty acids don t generate FADH 2. Saturated unsaturated Explain:

39

40 KETONE BODIES: An alternate fuel for cells

41 KETONE BODIES: An alternate fuel for cells: Liver mitochondria convert acetyl CoA derived from fatty acid oxidation into ketone bodies (acetoacetate, 3-hydroxybutyrate, and acetone). In peripheral tissue, ketone bodies (acetoacetate and 3-hydroxybutyrate) can be reconverted to acetyl CoA, which can be oxidized by the TCA cycle. ketone bodies are important sources of energy because: 1. They are soluble in aqueous solution and so do not need to be incorporated into lipoproteins or carried by albumin as do the other lipids. 2. They are produced in the liver when the amount of acetyl CoA present exceeds the oxidative capacity of the liver. 3. They are used in extrahepatic tissues, such as the skeletal & cardiac muscle, renal cortex and brain. ketone bodies are important during prolonged periods of fasting (ketone bodies spare glucose).

42 Synthesis of ketone bodies by the liver (ketogenesis) Liver mitochondria convert acetyl CoA derived from fatty acid oxidation into ketone bodies (acetoacetate, 3-hydroxybutyrate, and acetone). Elevated NADH and acetyl CoA lead to activate ketone body synthesis because: inhibits pyruvate dehydrogenase. (pyruvate acetyl CoA) activates pyruvate carboxylase. (pyruvate Oxaloacetate) The OAA is used by the liver for gluconeogenesis. Therefore, acetyl CoA is channeled into ketone body synthesis. Note: during Fatty acid oxidation the NAD+ to NADH ratio is low, and the rise in NADH shifts OAA to malate. This pushes acetyl CoA away from gluconeogenesis and into ketogenesis.

43 Ketone bodies are synthesized by two steps: first step, acetyl CoA forming acetoacetyl CoA, by reversal of the thiolase reaction. Mitochondrial HMG CoA synthase combines a third molecule of acetyl CoA with acetoacetyl CoA to produce HMG CoA (precursor of cholesterol). HMG CoA synthase is the rate-limiting step in the synthesis of ketone bodies, and is present in liver. HMG CoA is cleaved to produce acetoacetate and acetyl CoA. Acetoacetate can be reduced to form 3- hydroxybutyrate with NADH as the hydrogen donor. Acetoacetate can decarboxylate in the blood to form acetone a volatile, nonmetabolized that can be released in the breath. NAD+/NADH ratio is low during fatty acid oxidation.

44 Use of ketone bodies by the peripheral tissues: ketolysis ketone bodies elevated during fasting when ketone bodies are needed to provide energy to the peripheral tissues. 3-Hydroxybutyrate is oxidized to acetoacetate by 3-hydroxy butyrate dehydrogenase, producing NADH. Acetoacetate is then provided with a CoA molecule taken from succinyl CoA by succinyl CoA: acetoacetate CoA transferase (thiophorase). Reversible reaction. Acetoacetyl CoA, is removed by its conversion to two acetyl CoA. Extrahepatic tissues, such as the brain oxidize acetoacetate and 3-hydroxybutyrate. Liver produces ketone bodies but it lacks thiophorase, therefore, is unable to use ketone bodies as fuel. 3-hydroxy butyrate dehydrogenase

45 Ketoacidosis occurs when the rate of formation of ketone bodies is greater than their rate of use, as is seen in cases of uncontrolled, type 1 diabetes mellitus. A frequent symptom of diabetic ketoacidosis is a fruity odor on the breath, which results from increased production of acetone.

46 Science Should be as simple as possible, but not simpler. Albert Einstein

47 References: Biochemistry. Lippincott's Illustrated Reviews. 6 th Edition by, Richard A Harvey, Denise R. Ferrier. Lippincott Williams and Wilkins, a Wolters kluwer business

LIPID METABOLISM

LIPID METABOLISM LIPID METABOLISM LIPOGENESIS LIPOGENESIS LIPOGENESIS FATTY ACID SYNTHESIS DE NOVO FFA in the blood come from :- (a) Dietary fat (b) Dietary carbohydrate/protein in excess of need FA TAG Site of synthesis:-

More information

BIOL2171 ANU TCA CYCLE

BIOL2171 ANU TCA CYCLE TCA CYCLE IMPORTANCE: Oxidation of 2C Acetyl Co-A 2CO 2 + 3NADH + FADH 2 (8e-s donated to O 2 in the ETC) + GTP (energy) + Heat OVERVIEW: Occurs In the mitochondrion matrix. 1. the acetyl portion of acetyl-coa

More information

LIPID METABOLISM. Sri Widia A Jusman Department of Biochemistry & Molecular Biology FMUI

LIPID METABOLISM. Sri Widia A Jusman Department of Biochemistry & Molecular Biology FMUI LIPID METABOLISM Sri Widia A Jusman Department of Biochemistry & Molecular Biology FMUI Lipid metabolism is concerned mainly with fatty acids cholesterol Source of fatty acids from dietary fat de novo

More information

Lipid metabolism. Degradation and biosynthesis of fatty acids Ketone bodies

Lipid metabolism. Degradation and biosynthesis of fatty acids Ketone bodies Lipid metabolism Degradation and biosynthesis of fatty acids Ketone bodies Fatty acids (FA) primary fuel molecules in the fat category main use is for long-term energy storage high level of energy storage:

More information

23.1 Lipid Metabolism in Animals. Chapter 23. Micelles Lipid Metabolism in. Animals. Overview of Digestion Lipid Metabolism in

23.1 Lipid Metabolism in Animals. Chapter 23. Micelles Lipid Metabolism in. Animals. Overview of Digestion Lipid Metabolism in Denniston Topping Caret Copyright! The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 23 Fatty Acid Metabolism Triglycerides (Tgl) are emulsified into fat droplets

More information

Oxidation of Long Chain Fatty Acids

Oxidation of Long Chain Fatty Acids Oxidation of Long Chain Fatty Acids Dr NC Bird Oxidation of long chain fatty acids is the primary source of energy supply in man and animals. Hibernating animals utilise fat stores to maintain body heat,

More information

Roles of Lipids. principal form of stored energy major constituents of cell membranes vitamins messengers intra and extracellular

Roles of Lipids. principal form of stored energy major constituents of cell membranes vitamins messengers intra and extracellular Roles of Lipids principal form of stored energy major constituents of cell membranes vitamins messengers intra and extracellular = Oxidation of fatty acids Central energy-yielding pathway in animals. O

More information

CHY2026: General Biochemistry. Lipid Metabolism

CHY2026: General Biochemistry. Lipid Metabolism CHY2026: General Biochemistry Lipid Metabolism Lipid Digestion Lipid Metabolism Fats (triglycerides) are high metabolic energy molecules Fats yield 9.3 kcal of energy (carbohydrates and proteins 4.1 kcal)

More information

Ahmad Ulnar. Faisal Nimri ... Dr.Faisal

Ahmad Ulnar. Faisal Nimri ... Dr.Faisal 24 Ahmad Ulnar Faisal Nimri... Dr.Faisal Fatty Acid Synthesis - Occurs mainly in the Liver (to store excess carbohydrates as triacylglycerols(fat)) and in lactating mammary glands (for the production of

More information

Fatty Acid and Triacylglycerol Metabolism 1

Fatty Acid and Triacylglycerol Metabolism 1 Fatty Acid and Triacylglycerol Metabolism 1 Mobilization of stored fats and oxidation of fatty acids Lippincott s Chapter 16 What is the first lecture about What is triacylglycerol Fatty acids structure

More information

Synthesis and degradation of fatty acids Martina Srbová

Synthesis and degradation of fatty acids Martina Srbová Synthesis and degradation of fatty acids Martina Srbová martina.srbova@lfmotol.cuni.cz Fatty acids (FA) mostly an even number of carbon atoms and linear chain in esterified form as component of lipids

More information

Biochemistry: A Short Course

Biochemistry: A Short Course Tymoczko Berg Stryer Biochemistry: A Short Course Second Edition CHAPTER 27 Fatty Acid Degradation Dietary Lipid (Triacylglycerol) Metabolism - In the small intestine, fat particles are coated with bile

More information

CLINICAL BIOCHEMISTRY - 5 LIPID METABOLISM

CLINICAL BIOCHEMISTRY - 5 LIPID METABOLISM CLINICAL BIOCHEMISTRY - 5 LIPID METABOLISM DIGESTIVE MECHANISM FOR LIPIDS The average lipid intake is about 80g/day, of which more than 90% is triacylglycerol (TAG); the remainder consists of cholesterol,

More information

Fatty acid breakdown

Fatty acid breakdown Fatty acids contain a long hydrocarbon chain and a terminal carboxylate group. Most contain between 14 and 24 carbon atoms. The chains may be saturated or contain double bonds. The complete oxidation of

More information

6. How Are Fatty Acids Produced? 7. How Are Acylglycerols and Compound Lipids Produced? 8. How Is Cholesterol Produced?

6. How Are Fatty Acids Produced? 7. How Are Acylglycerols and Compound Lipids Produced? 8. How Is Cholesterol Produced? Lipid Metabolism Learning bjectives 1 How Are Lipids Involved in the Generationand Storage of Energy? 2 How Are Lipids Catabolized? 3 What Is the Energy Yield from the xidation of Fatty Acids? 4 How Are

More information

Fatty acids synthesis

Fatty acids synthesis Fatty acids synthesis The synthesis start from Acetyl COA the first step requires ATP + reducing power NADPH! even though the oxidation and synthesis are different pathways but from chemical part of view

More information

OVERVIEW M ET AB OL IS M OF FR EE FA TT Y AC ID S

OVERVIEW M ET AB OL IS M OF FR EE FA TT Y AC ID S LIPOLYSIS LIPOLYSIS OVERVIEW CATABOLISM OF FREE FATTY ACIDS Nonesterified fatty acids Source:- (a) breakdown of TAG in adipose tissue (b) action of Lipoprotein lipase on plasma TAG Combined with Albumin

More information

number Done by Corrected by Doctor Faisal Al-Khatibe

number Done by Corrected by Doctor Faisal Al-Khatibe number 24 Done by Mohammed tarabieh Corrected by Doctor Faisal Al-Khatibe 1 P a g e *Please look over the previous sheet about fatty acid synthesis **Oxidation(degradation) of fatty acids, occurs in the

More information

Biosynthesis of Fatty Acids. By Dr.QUTAIBA A. QASIM

Biosynthesis of Fatty Acids. By Dr.QUTAIBA A. QASIM Biosynthesis of Fatty Acids By Dr.QUTAIBA A. QASIM Fatty Acids Definition Fatty acids are comprised of hydrocarbon chains terminating with carboxylic acid groups. Fatty acids and their associated derivatives

More information

Lecture 36. Key Concepts. Overview of lipid metabolism. Reactions of fatty acid oxidation. Energy yield from fatty acid oxidation

Lecture 36. Key Concepts. Overview of lipid metabolism. Reactions of fatty acid oxidation. Energy yield from fatty acid oxidation Lecture 36 Lipid Metabolism 1 Fatty Acid Oxidation Ketone Bodies Key Concepts Overview of lipid metabolism Reactions of fatty acid oxidation Energy yield from fatty acid oxidation Formation of ketone bodies

More information

Lipid Metabolism. Remember fats?? Triacylglycerols - major form of energy storage in animals

Lipid Metabolism. Remember fats?? Triacylglycerols - major form of energy storage in animals Remember fats?? Triacylglycerols - major form of energy storage in animals Your energy reserves: ~0.5% carbs (glycogen + glucose) ~15% protein (muscle, last resort) ~85% fat Why use fat for energy? 1 gram

More information

BCM 221 LECTURES OJEMEKELE O.

BCM 221 LECTURES OJEMEKELE O. BCM 221 LECTURES BY OJEMEKELE O. OUTLINE INTRODUCTION TO LIPID CHEMISTRY STORAGE OF ENERGY IN ADIPOCYTES MOBILIZATION OF ENERGY STORES IN ADIPOCYTES KETONE BODIES AND KETOSIS PYRUVATE DEHYDROGENASE COMPLEX

More information

Fatty Acid and Triacylglycerol Metabolism 1

Fatty Acid and Triacylglycerol Metabolism 1 Fatty Acid and Triacylglycerol Metabolism 1 Mobilization of stored fats and oxidation of fatty acids Lippincott s Chapter 16 What is the first lecture about What is triacylglycerol Fatty acids structure

More information

Fatty acid oxidation. doc. Ing. Zenóbia Chavková, CSc.

Fatty acid oxidation. doc. Ing. Zenóbia Chavková, CSc. Fatty acid oxidation doc. Ing. Zenóbia Chavková, CSc. Physiological functions of fatty acids 1. Structural components of cell membranes (phospholipids and sphingolipids) 2. Energy storage (triacylglycerols)

More information

Biochemistry Sheet 27 Fatty Acid Synthesis Dr. Faisal Khatib

Biochemistry Sheet 27 Fatty Acid Synthesis Dr. Faisal Khatib Page1 بسم رلاهللا On Thursday, we discussed the synthesis of fatty acids and its regulation. We also went on to talk about the synthesis of Triacylglycerol (TAG). Last time, we started talking about the

More information

Biochemistry: A Short Course

Biochemistry: A Short Course Tymoczko Berg Stryer Biochemistry: A Short Course Second Edition CHAPTER 28 Fatty Acid Synthesis 2013 W. H. Freeman and Company Chapter 28 Outline 1. The first stage of fatty acid synthesis is transfer

More information

GENERAL FEATURES OF FATTY ACIDS BIOSYNTHESIS

GENERAL FEATURES OF FATTY ACIDS BIOSYNTHESIS 1 GENERAL FEATURES OF FATTY ACIDS BIOSYNTHESIS 1. Fatty acids may be synthesized from dietary glucose via pyruvate. 2. Fatty acids are the preferred fuel source for the heart and the primary form in which

More information

CHM333 LECTURE 34: 11/30 12/2/09 FALL 2009 Professor Christine Hrycyna

CHM333 LECTURE 34: 11/30 12/2/09 FALL 2009 Professor Christine Hrycyna Lipid Metabolism β-oxidation FA Acetyl-CoA Triacylglycerols (TAGs) and glycogen are the two major forms of stored energy in vertebrates Glycogen can supply ATP for muscle contraction for less than an hour

More information

number Done by Corrected by Doctor F. Al-Khateeb

number Done by Corrected by Doctor F. Al-Khateeb number 23 Done by A. Rawajbeh Corrected by Doctor F. Al-Khateeb Ketone bodies Ketone bodies are used by the peripheral tissues like the skeletal and cardiac muscles, where they are the preferred source

More information

Chapter 22, Fatty Acid Metabolism CH 3 (CH 2 ) 14 CO 2 R C C O2 CH 2 OH O R. Lipase + 3 H 2 O

Chapter 22, Fatty Acid Metabolism CH 3 (CH 2 ) 14 CO 2 R C C O2 CH 2 OH O R. Lipase + 3 H 2 O hapter 22, Fatty Acid Metabolism Pages: 603-613 I. Introduction - Fatty acids have 4 major physiological roles: - omponents of phospholipids and glycolipids (membranes) - Attachment to Proteins targets

More information

Synthesis of Fatty Acids and Triacylglycerol

Synthesis of Fatty Acids and Triacylglycerol Synthesis of Fatty Acids and Triacylglycerol Lippincott s Chapter 16 Fatty Acid Synthesis Mainly in the Liver Requires Carbon Source: Acetyl CoA Reducing Power: NADPH 8 CH 3 COO C 15 H 33 COO Energy Input:

More information

Chapter 16 - Lipid Metabolism

Chapter 16 - Lipid Metabolism Chapter 16 - Lipid Metabolism Fatty acids have four major physiologic roles in the cell: Building blocks of phospholipids and glycolipids Added onto proteins to create lipoproteins, which targets them

More information

Summary of fatty acid synthesis

Summary of fatty acid synthesis Lipid Metabolism, part 2 1 Summary of fatty acid synthesis 8 acetyl CoA + 14 NADPH + 14 H+ + 7 ATP palmitic acid (16:0) + 8 CoA + 14 NADP + + 7 ADP + 7 Pi + 7 H20 1. The major suppliers of NADPH for fatty

More information

ANSC/NUTR 618 LIPIDS & LIPID METABOLISM. Triacylglycerol and Fatty Acid Metabolism

ANSC/NUTR 618 LIPIDS & LIPID METABOLISM. Triacylglycerol and Fatty Acid Metabolism ANSC/NUTR 618 LIPIDS & LIPID METABOLISM II. Triacylglycerol synthesis A. Overall pathway Glycerol-3-phosphate + 3 Fatty acyl-coa à Triacylglycerol + 3 CoASH B. Enzymes 1. Acyl-CoA synthase 2. Glycerol-phosphate

More information

Lipid Metabolism * OpenStax

Lipid Metabolism * OpenStax OpenStax-CNX module: m46462 1 Lipid Metabolism * OpenStax This work is produced by OpenStax-CNX and licensed under the Creative Commons Attribution License 3.0 By the end of this section, you will be able

More information

Lehninger 5 th ed. Chapter 17

Lehninger 5 th ed. Chapter 17 Lehninger 5 th ed. Chapter 17 December 26, 2010 Prof. Shimon Schuldiner Email: Shimon.Schuldiner@huji.ac.il Phone: 6585992 CHAPTER 17 Fatty Acid Catabolism Key topics: How fats are digested in animals

More information

the fates of acetyl coa which produced by B oixidation :

the fates of acetyl coa which produced by B oixidation : Ketone bodies the fates of acetyl coa which produced by B oixidation : 1) oxidized at the TCA cycle 2)synthesis of ketone bodies Ketone bodies : 1)acetoacetate 2) acetone 3) 3_hydroxybutyrate Naming acetonacetone:

More information

BCH 4054 Spring 2001 Chapter 24 Lecture Notes

BCH 4054 Spring 2001 Chapter 24 Lecture Notes BCH 4054 Spring 2001 Chapter 24 Lecture Notes 1 Chapter 24 Fatty Acid Catabolism 2 Fatty Acids as Energy Source Triglycerides yield 37 kj/g dry weight Protein 17 kj/g Glycogen 16 kj/g (even less wet weight)

More information

BIOSYNTHESIS OF FATTY ACIDS. doc. Ing. Zenóbia Chavková, CSc.

BIOSYNTHESIS OF FATTY ACIDS. doc. Ing. Zenóbia Chavková, CSc. BIOSYNTHESIS OF FATTY ACIDS doc. Ing. Zenóbia Chavková, CSc. The pathway for the of FAs is not the reversal of the oxidation pathway Both pathways are separated within different cellular compartments In

More information

Lipid Metabolism. Catabolism Overview

Lipid Metabolism. Catabolism Overview Lipid Metabolism Pratt & Cornely, Chapter 17 Catabolism Overview Lipids as a fuel source from diet Beta oxidation Mechanism ATP production Ketone bodies as fuel 1 High energy More reduced Little water

More information

Part III => METABOLISM and ENERGY. 3.4 Lipid Catabolism 3.4a Fatty Acid Degradation 3.4b Ketone Bodies

Part III => METABOLISM and ENERGY. 3.4 Lipid Catabolism 3.4a Fatty Acid Degradation 3.4b Ketone Bodies Part III => METABOLISM and ENERGY 3.4 Lipid Catabolism 3.4a Fatty Acid Degradation 3.4b Ketone Bodies Section 3.4a: Fatty Acid Degradation Synopsis 3.4a - Triglycerides (or fats) in the diet or adipose

More information

Biosynthesis of Triacylglycerides (TG) in liver. Mobilization of stored fat and oxidation of fatty acids

Biosynthesis of Triacylglycerides (TG) in liver. Mobilization of stored fat and oxidation of fatty acids Biosynthesis of Triacylglycerides (TG) in liver Mobilization of stored fat and oxidation of fatty acids Activation of hormone sensitive lipase This enzyme is activated when phosphorylated (3,5 cyclic AMPdependent

More information

number Done by Corrected by Doctor

number Done by Corrected by Doctor number 20 Done by Corrected by Rana Ghassan Doctor Only 4 questions in the mid-term exam are based on the 4 lectures to be given by Dr Faisal. Dr Faisal will give us 10 lectures, the first 4 are included

More information

Integration Of Metabolism

Integration Of Metabolism Integration Of Metabolism Metabolism Consist of Highly Interconnected Pathways The basic strategy of catabolic metabolism is to form ATP, NADPH, and building blocks for biosyntheses. 1. ATP is the universal

More information

Tala Saleh. Razi Kittaneh ... Nayef Karadsheh

Tala Saleh. Razi Kittaneh ... Nayef Karadsheh Tala Saleh Razi Kittaneh... Nayef Karadsheh β-oxidation of Fatty Acids The oxidation of fatty acids occurs in 3 steps: Step 1: Activation of the Fatty acid FA + HS-CoA + ATP FA-CoA + AMP + PPi - The fatty

More information

Biochemistry - I SPRING Mondays and Wednesdays 9:30-10:45 AM (MR-1307) Lectures Based on Profs. Kevin Gardner & Reza Khayat

Biochemistry - I SPRING Mondays and Wednesdays 9:30-10:45 AM (MR-1307) Lectures Based on Profs. Kevin Gardner & Reza Khayat Biochemistry - I Mondays and Wednesdays 9:30-10:45 AM (MR-1307) SPRING 2017 Lectures 21-22 Based on Profs. Kevin Gardner & Reza Khayat 1 Outline Vertebrate processing of dietary lipids Mobilization of

More information

Energy storage in cells

Energy storage in cells Energy storage in cells Josef Fontana EC - 58 Overview of the lecture Introduction to the storage substances of human body Overview of storage compounds in the body Glycogen metabolism Structure of glycogen

More information

Voet Biochemistry 3e John Wiley & Sons, Inc.

Voet Biochemistry 3e John Wiley & Sons, Inc. * * Voet Biochemistry 3e Lipid Metabolism Part I: (Chap. 25, sec.1-3) Glucose C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O G o = -2823 kj/mol Fats (palmitic acid) C 16 H 32 O 2 + 23 O 2 16 CO 2 + 16 H 2 O G o

More information

Synthesis of Fatty Acids and Triacylglycerol

Synthesis of Fatty Acids and Triacylglycerol Fatty Acid Synthesis Synthesis of Fatty Acids and Triacylglycerol Requires Carbon Source: Reducing Power: NADPH Energy Input: ATP Why Energy? Why Energy? Fatty Acid Fatty Acid + n(atp) ΔG o : -ve Fatty

More information

ANSC/NUTR 618 Lipids & Lipid Metabolism

ANSC/NUTR 618 Lipids & Lipid Metabolism I. Overall concepts A. Definitions ANC/NUTR 618 Lipids & Lipid Metabolism 1. De novo synthesis = synthesis from non-fatty acid precursors a. Carbohydrate precursors (glucose, lactate, and pyruvate) b.

More information

MILK BIOSYNTHESIS PART 3: FAT

MILK BIOSYNTHESIS PART 3: FAT MILK BIOSYNTHESIS PART 3: FAT KEY ENZYMES (FROM ALL BIOSYNTHESIS LECTURES) FDPase = fructose diphosphatase Citrate lyase Isocitrate dehydrogenase Fatty acid synthetase Acetyl CoA carboxylase Fatty acyl

More information

Points 1. Following is the overall reaction catalyzed by the Calvin-Benson cycle:

Points 1. Following is the overall reaction catalyzed by the Calvin-Benson cycle: BCH 4054 February 22, 2002 HOUR TEST 2 NAME_ Points 1. Following is the overall reaction catalyzed by the Calvin-Benson cycle: CO 2 + 3ATP + 2NADPH 1/3 glyceraldehyde-3-p + 3ADP + 2NADP + Give the structures

More information

Companion to Biosynthesis of Ketones & Cholesterols, Regulation of Lipid Metabolism Lecture Notes

Companion to Biosynthesis of Ketones & Cholesterols, Regulation of Lipid Metabolism Lecture Notes Companion to Biosynthesis of Ketones & Cholesterols, Regulation of Lipid Metabolism Lecture Notes The major site of acetoacetate and 3-hydorxybutyrate production is in the liver. 3-hydorxybutyrate is the

More information

2-more complex molecules (fatty acyl esters) as triacylglycerols.

2-more complex molecules (fatty acyl esters) as triacylglycerols. ** Fatty acids exist in two forms:- 1-free fatty acids (unesterified) 2-more complex molecules (fatty acyl esters) as triacylglycerols. ** most tissues might use fatty acids as source of energy during

More information

Biochemistry. 5.3) Fat Metabolism

Biochemistry. 5.3) Fat Metabolism Biochemistry 5. Bio-Energetics & ATP 5.3) Fat Metabolism Prof. Dr. Klaus Heese Lipids Metabolism Introduction basic physiological background info 1 Definition of Lipids Substances in dairy foods Known

More information

Integrative Metabolism: Significance

Integrative Metabolism: Significance Integrative Metabolism: Significance Energy Containing Nutrients Carbohydrates Fats Proteins Catabolism Energy Depleted End Products H 2 O NH 3 ADP + Pi NAD + NADP + FAD + Pi NADH+H + NADPH+H + FADH2 Cell

More information

number Done by Corrected by Doctor Nayef Karadsheh

number Done by Corrected by Doctor Nayef Karadsheh number 13 Done by Asma Karameh Corrected by Saad hayek Doctor Nayef Karadsheh Gluconeogenesis This lecture covers gluconeogenesis with aspects of: 1) Introduction to glucose distribution through tissues.

More information

Lipids digestion and absorption, Biochemistry II

Lipids digestion and absorption, Biochemistry II Lipids digestion and absorption, blood plasma lipids, lipoproteins Biochemistry II Lecture 1 2008 (J.S.) Triacylglycerols (as well as free fatty acids and both free and esterified cholesterol) are very

More information

number Done by Corrected by Doctor Faisal Al-Khatib

number Done by Corrected by Doctor Faisal Al-Khatib number 22 Done by Baraa Ayed Corrected by Yaseen Fatayer Doctor Faisal Al-Khatib 1 P a g e Today we are going to cover these concepts: Oxidation of odd number fatty acids Oxidation of very long fatty acids

More information

CHM333 LECTURE 34-36: 4/18 20/7/12 SPRING 2012 Professor Christine Hrycyna

CHM333 LECTURE 34-36: 4/18 20/7/12 SPRING 2012 Professor Christine Hrycyna Lipid Metabolism β-oxidation FA! Acetyl-CoA Triacylglycerols (TAGs) and glycogen are the two major forms of stored energy in vertebrates Glycogen can supply ATP for muscle contraction for less than an

More information

Fatty acid synthesis. Dr. Nalini Ganesan M.Sc., Ph.D Associate Professor Department of Biochemistry SRMC & RI (DU) Porur, Chennai - 116

Fatty acid synthesis. Dr. Nalini Ganesan M.Sc., Ph.D Associate Professor Department of Biochemistry SRMC & RI (DU) Porur, Chennai - 116 Fatty acid synthesis Dr. Nalini Ganesan M.Sc., Ph.D Associate Professor Department of Biochemistry SRMC & RI (DU) Porur, Chennai 116 Harper s biochemistry 24 th ed, Pg 218 Fatty acid Synthesis Known as

More information

Moh Tarek + Suhayb. Tamara Al-Azzeh + Asmaa Aljeelani ... Faisal

Moh Tarek + Suhayb. Tamara Al-Azzeh + Asmaa Aljeelani ... Faisal 28 Moh Tarek + Suhayb Tamara Al-Azzeh + Asmaa Aljeelani... Faisal Digestion of dietary lipids Lipid digestion and absorption are complex processes. They involve soluble enzymes, substrates with different

More information

Medical Biochemistry and Molecular Biology department

Medical Biochemistry and Molecular Biology department Medical Biochemistry and Molecular Biology department Cardiac Fuels [Sources of energy for the Cardiac muscle] Intended learning outcomes of the lecture: By the end of this lecture you would be able to:-

More information

Lecture 16. Finish lipid metabolism (Triglycerides, Isoprenoids/Steroids, Glyoxylate cycle) Amino acid metabolism (Urea cycle) Google Man III

Lecture 16. Finish lipid metabolism (Triglycerides, Isoprenoids/Steroids, Glyoxylate cycle) Amino acid metabolism (Urea cycle) Google Man III Lecture 16 Finish lipid metabolism (Triglycerides, Isoprenoids/Steroids, Glyoxylate cycle) Amino acid metabolism (Urea cycle) Google Man III The Powertrain of Human Metabolism (verview) CARBHYDRATES PRTEINS

More information

Department of Medical Biochemistry. Semmelweis University. Dr. Beáta Törőcsik. Lipid metabolism

Department of Medical Biochemistry. Semmelweis University. Dr. Beáta Törőcsik. Lipid metabolism Department of Medical Biochemistry Semmelweis University Dr. Beáta Törőcsik Lipid metabolism 2017. 10. 13. 2017. 10. 19. 2017. 10. 20. 2017. 10. 26. : not to learn * : structures to learn Harper s Biochemistry

More information

MBG304 Biochemistry Lecture 8- Metabolism: Lipid metabolism. Hikmet Geçkil, Professor Department of Molecular Biology and Genetics Inonu University

MBG304 Biochemistry Lecture 8- Metabolism: Lipid metabolism. Hikmet Geçkil, Professor Department of Molecular Biology and Genetics Inonu University MBG304 Biochemistry Lecture 8- Metabolism: Lipid metabolism Hikmet Geçkil, Professor Department of Molecular Biology and Genetics Inonu University In the past few lectures we have seen how energy can be

More information

Lipids and Classification:

Lipids and Classification: Lipids and Classification: Lipids: Biological lipids are a chemically diverse group of organic compounds which are insoluble or only poorly soluble in water. They are readily soluble in non-polar solvents

More information

Chapter 26 Biochemistry 5th edition. phospholipids. Sphingolipids. Cholesterol. db=books&itool=toolbar

Chapter 26 Biochemistry 5th edition. phospholipids. Sphingolipids. Cholesterol.   db=books&itool=toolbar http://www.ncbi.nlm.nih.gov/sites/entrez? db=books&itool=toolbar 1 The surface of a soap bubble is a bilayer formed by detergent molecules 2 Chapter 26 Biochemistry 5th edition phospholipids Sphingolipids

More information

Integration Of Metabolism

Integration Of Metabolism Integration Of Metabolism Metabolism Consist of Highly Interconnected Pathways The basic strategy of catabolic metabolism is to form ATP, NADPH, and building blocks for biosyntheses. 1. ATP is the universal

More information

Integration of Metabolism 1. made by: Noor M. ALnairat. Sheet No. 18

Integration of Metabolism 1. made by: Noor M. ALnairat. Sheet No. 18 Integration of Metabolism 1 made by: Noor M. ALnairat Sheet No. 18 Data :24/11/2016 SLIDE 2: Metabolism Consist of Highly Interconnected Pathways The basic strategy of catabolic metabolism is to form ATP,

More information

Biosynthesis of Fatty Acids

Biosynthesis of Fatty Acids Biosynthesis of Fatty Acids Fatty acid biosynthesis takes place in the cytosol rather than the mitochondria and requires a different activation mechanism and different enzymes and coenzymes than fatty

More information

Multiple choice: Circle the best answer on this exam. There are 12 multiple choice questions, each question is worth 3 points.

Multiple choice: Circle the best answer on this exam. There are 12 multiple choice questions, each question is worth 3 points. CHEM 4420 Exam 4 Spring 2015 Dr. Stone Page 1 of 6 Name Use complete sentences when requested. There are 120 possible points on this exam. Therefore there are 20 bonus points. Multiple choice: Circle the

More information

Glycolysis Part 2. BCH 340 lecture 4

Glycolysis Part 2. BCH 340 lecture 4 Glycolysis Part 2 BCH 340 lecture 4 Regulation of Glycolysis There are three steps in glycolysis that have enzymes which regulate the flux of glycolysis These enzymes catalyzes irreversible reactions of

More information

Biology 638 Biochemistry II Exam-3. (Note that you are not allowed to use any calculator)

Biology 638 Biochemistry II Exam-3. (Note that you are not allowed to use any calculator) Biology 638 Biochemistry II Exam-3 (Note that you are not allowed to use any calculator) 1. In the non-cyclic pathway, electron pathway is. Select the most accurate one. a. PSII PC Cyt b 6 f PC PSI Fd-NADP

More information

L1, 2 : Biochemical Aspects of Digestion of Lipids, Proteins, and Carbohydrates

L1, 2 : Biochemical Aspects of Digestion of Lipids, Proteins, and Carbohydrates L1, 2 : Biochemical Aspects of Digestion of Lipids, Proteins, and Carbohydrates OBJECTIVES: Understand the process of digestion of dietary lipids, protein and carbohydrates including, the organs involved,

More information

#16 made by Nour omar corrected by laith sorour date 17/11

#16 made by Nour omar corrected by laith sorour date 17/11 Lipid metabolism 2 #16 made by Nour omar corrected by laith sorour date 17/11 Keton Bodies Ketone bodies: acetone, -hydroxybutyrate, and acetoacetate formed principally in the liver mitochondria. can be

More information

FAD FADH2. glycerol-3- phosphate. dehydrogenase. This DHAP is metabolically no different from that produced in glycolysis.

FAD FADH2. glycerol-3- phosphate. dehydrogenase. This DHAP is metabolically no different from that produced in glycolysis. 1 Lipid Metabolism: ow that we are aware of the types of lipids in our bodies, it is important to see how we make them or break them. We will start our discussion with triacylglyceride degradation, and

More information

Lecture: 26 OXIDATION OF FATTY ACIDS

Lecture: 26 OXIDATION OF FATTY ACIDS Lecture: 26 OXIDATION OF FATTY ACIDS Fatty acids obtained by hydrolysis of fats undergo different oxidative pathways designated as alpha ( ), beta ( ) and omega ( ) pathways. -oxidation -Oxidation of fatty

More information

Objectives By the end of lecture the student should:

Objectives By the end of lecture the student should: Objectives By the end of lecture the student should: Discuss β oxidation of fatty acids. Illustrate α oxidation of fatty acids. Understand ω oxidation of fatty acids. List sources and fates of active acetate.

More information

Factors to Consider in the Study of Biomolecules

Factors to Consider in the Study of Biomolecules Factors to Consider in the Study of Biomolecules What are the features of the basic building blocks? (ex: monosaccharides, alcohols, fatty acids, amino acids) 1) General structure and functional groups

More information

Cholesterol and its transport. Alice Skoumalová

Cholesterol and its transport. Alice Skoumalová Cholesterol and its transport Alice Skoumalová 27 carbons Cholesterol - structure Cholesterol importance A stabilizing component of cell membranes A precursor of bile salts A precursor of steroid hormones

More information

Leen Alsahele. Razan Al-zoubi ... Faisal

Leen Alsahele. Razan Al-zoubi ... Faisal 25 Leen Alsahele Razan Al-zoubi... Faisal last time we started talking about regulation of fatty acid synthesis and degradation *regulation of fatty acid synthesis by: 1- regulation of acetyl CoA carboxylase

More information

Citric Acid Cycle: Central Role in Catabolism. Entry of Pyruvate into the TCA cycle

Citric Acid Cycle: Central Role in Catabolism. Entry of Pyruvate into the TCA cycle Citric Acid Cycle: Central Role in Catabolism Stage II of catabolism involves the conversion of carbohydrates, fats and aminoacids into acetylcoa In aerobic organisms, citric acid cycle makes up the final

More information

BASIC SCIENCES & BIOCHEMISTRY FOR BETZPAENIC BRIMBLERS

BASIC SCIENCES & BIOCHEMISTRY FOR BETZPAENIC BRIMBLERS BASIC SCIENCES & BIOCHEMISTRY FOR BETZPAENIC BRIMBLERS Lymphatic Vessels One main lymph vessel receives lymph from the right upper arm and the right side of the head and the thorax and empties into the

More information

Plasma lipoproteins & atherosclerosis by. Prof.Dr. Maha M. Sallam

Plasma lipoproteins & atherosclerosis by. Prof.Dr. Maha M. Sallam Biochemistry Department Plasma lipoproteins & atherosclerosis by Prof.Dr. Maha M. Sallam 1 1. Recognize structures,types and role of lipoproteins in blood (Chylomicrons, VLDL, LDL and HDL). 2. Explain

More information

Integration & Hormone Regulation

Integration & Hormone Regulation Integration Branchpoints in metabolism where metabolites can go several directions 1. Glucose 6-phosphate Energy needed (low energy charge): glycolysis Low blood sugar: high [glucagon], low [insulin] glycogen

More information

Lipid and Amino Acid Metabolism

Lipid and Amino Acid Metabolism CHEM 3331 Fundamentals of Biochemistry Chapter 14 Lipid and Amino Acid Metabolism Organic and Biochemistry for Today Spencer L. Seager / Michael R. Slabaugh Mr. Kevin A. Boudreaux Angelo State University

More information

Lecture 16. Finish lipid metabolism (Triglycerides, Isoprenoids/Steroids, Glyoxylate cycle) Amino acid metabolism (Urea cycle) Google Man III

Lecture 16. Finish lipid metabolism (Triglycerides, Isoprenoids/Steroids, Glyoxylate cycle) Amino acid metabolism (Urea cycle) Google Man III Lecture 16 Finish lipid metabolism (Triglycerides, Isoprenoids/Steroids, Glyoxylate cycle) Amino acid metabolism (Urea cycle) Google Man III The Powertrain of Human Metabolism (verview) CARBHYDRATES PRTEINS

More information

Intermediary metabolism. Eva Samcová

Intermediary metabolism. Eva Samcová Intermediary metabolism Eva Samcová Metabolic roles of tissues Four major tissues play a dominant role in fuel metabolism : liver, adipose, muscle, and brain. These tissues do not function in isolation.

More information

In glycolysis, glucose is converted to pyruvate. If the pyruvate is reduced to lactate, the pathway does not require O 2 and is called anaerobic

In glycolysis, glucose is converted to pyruvate. If the pyruvate is reduced to lactate, the pathway does not require O 2 and is called anaerobic Glycolysis 1 In glycolysis, glucose is converted to pyruvate. If the pyruvate is reduced to lactate, the pathway does not require O 2 and is called anaerobic glycolysis. If this pyruvate is converted instead

More information

Physiology Unit 1 METABOLISM OF LIPIDS AND PROTEINS

Physiology Unit 1 METABOLISM OF LIPIDS AND PROTEINS Physiology Unit 1 METABOLISM OF LIPIDS AND PROTEINS Alternate Fuel Sources When glucose levels are low Proteins and Triglycerides will be metabolized Tissues will use different fuel sources depending on:

More information

Cholesterol metabolism. Function Biosynthesis Transport in the organism Hypercholesterolemia

Cholesterol metabolism. Function Biosynthesis Transport in the organism Hypercholesterolemia Cholesterol metabolism Function Biosynthesis Transport in the organism Hypercholesterolemia - component of all cell membranes - precursor of bile acids steroid hormones vitamin D Cholesterol Sources: dietary

More information

Fatty Acid Degradation. Catabolism Overview. TAG and FA 11/11/2015. Chapter 27, Stryer Short Course. Lipids as a fuel source diet Beta oxidation

Fatty Acid Degradation. Catabolism Overview. TAG and FA 11/11/2015. Chapter 27, Stryer Short Course. Lipids as a fuel source diet Beta oxidation Fatty Acid Degradation Chapter 27, Stryer Short Course Catabolism verview Lipids as a fuel source diet Beta oxidation saturated Unsaturated dd chain Ketone bodies as fuel Physiology High energy More reduced

More information

Digestion and transport of TAG by plasma lipoproteins

Digestion and transport of TAG by plasma lipoproteins Digestion and transport of TAG by plasma lipoproteins Lipoproteins are multimolecular complexes of lipids and proteins, they are not macromolecules They transport lipids in the plasma because lipids are

More information

Marah Bitar. Faisal Nimri ... Nafeth Abu Tarboosh

Marah Bitar. Faisal Nimri ... Nafeth Abu Tarboosh 8 Marah Bitar Faisal Nimri... Nafeth Abu Tarboosh Summary of the 8 steps of citric acid cycle Step 1. Acetyl CoA joins with a four-carbon molecule, oxaloacetate, releasing the CoA group and forming a six-carbon

More information

Dr MS Islam Sr. Lecturer of Biochemistry School of Life Sciences, Westville Campus

Dr MS Islam Sr. Lecturer of Biochemistry School of Life Sciences, Westville Campus Dr MS Islam Sr. Lecturer of Biochemistry School of Life Sciences, Westville Campus Lipids play roles both in energy metabolism and in aspects of biological structure and functions The great bulk of lipid

More information

Unit IV Problem 3 Biochemistry: Cholesterol Metabolism and Lipoproteins

Unit IV Problem 3 Biochemistry: Cholesterol Metabolism and Lipoproteins Unit IV Problem 3 Biochemistry: Cholesterol Metabolism and Lipoproteins - Cholesterol: It is a sterol which is found in all eukaryotic cells and contains an oxygen (as a hydroxyl group OH) on Carbon number

More information

Lipid metabolism I Triacylglycerols

Lipid metabolism I Triacylglycerols Lipid metabolism I Triacylglycerols Biochemistry I Lecture 8 2008 (J.S.) Major classes of lipids Simple lipids Triacylglycerols serve as energy-providing nutrients, the turnover about 100 g per day in

More information