Β Oxidation Of Saturated Fatty Acids Has Four Basic Steps
β Oxidation Mitochondrial oxidation of fatty acids takes place in three stages (Fig. 16-7). In the first stage-β oxidation-the fatty acids undergo oxidative removal of successive two-carbon units in the form of acetyl-CoA, starting from the carboxyl end of the fatty acyl chain. For example, the 16-carbon fatty acid palmitic acid (palmitate at pH 7) undergoes seven passes through this oxidative sequence, in each pass losing two carbons as acetyl-CoA. At the end of seven cycles the last two carbons of palmitate (originally C-15 and C-16) are left as acetyl-CoA. The overall result is the conversion of the 16-carbon chain of palmitate to eight two-carbon acetyl-CoA molecules. Formation of each molecule of acetyl-CoA requires removal of four hydrogen atoms (two pairs of electrons and four H+) from the fatty acyl moiety by the action of dehydrogenases. In the second stage of fatty acid oxidation the acetyl residues of acetyl-CoA are oxidized to CO2 via the citric acid cycle, which also takes place in the mitochondrial matrix. Acetyl-CoA derived from fatty acid oxidation thus enters a final common pathway of oxidation along with acetyl-CoA derived from glucose via glycolysis and pyruvate oxidation (see Fig. 15-1). The first two stages of fatty acid oxidation produce the reduced electron carriers NADH and FADH2, which in the third stage donate electrons to the mitochondrial respiratory chain, through which the electrons are carried to oxygen (Fig. 16-7). Coupled to this flow of electrons is the phosphorylation of ADP to ATP, to be described in Chapter 18. Thus energy released by fatty acid oxidation is conserved as ATP. We will now look in more detail at the first stage of fatty acid oxidation, for the simple case of a saturated chain with an even number of carbons, and for t Continue reading >>
Exam 2 Flashcards
*Glycogen has a high energy yield per liter of O2 uptake (~5.1 kcal/L O2) *Glycogen can be metabolized both aerobically and anaerobically *Rapid activation of the metabolic pathways for glycogen metabolism *Glycogen concentration can be greatly increased by training and diet *Glycogen can be the sole source of energy during heavy exercise *Glycogen is stored with large amount of H20, thus reducing the caloric value of the storage form (1.1 kcal/g glycogen) *The total amount of glycogen that can be stored is relatively small *Anaerobic use of glycogen results in the accumulation of lactate (and thus pH), which may interfere with a number of cellular processes *Muscle cells are dependent upon their internal glycogen stores; when these stores are depleted, moderately heavy exercise cannot continue Process by which glycogen is broken into glucose-1-phosphate to be used by muscles *Requires 10-12 (depending on where the reaction stops) enzymatic reactions to breakdown glucose and glycogen into ATP *Glycolysis that occurs in glycolytic system is anaerobic *Glucose is a 6 carbon structure (C6H12O6) *Glucose is broken down into two 3-carbon structures called pyruvic acid *The pyruvic acid is then converted to Lactic acid *The breakdown of carbohydrates are the only nutrient whose stored energy can be used to generate ATP anaerobically *The Electron Transport Chain (ETS) is coupled to the Krebs Cycle *The hydrogen ions that are produced from glycolysis and the krebs cycle combine with NAD and FAD, forming NADH and FADH2 What does the forming of NADH and FADH2 in the Electron Transport Chain accomplish? 1) It prevents the build up of H+, thereby limiting acidification of the msucle and blood 2) Carries the H+ ion to the ETS where the H+ is passed through a series of reactions fo Continue reading >>
We Really Can Make Glucose From Fatty Acids After All! O Textbook, How Thy Biochemistry Hast Deceived Me!
Biochemistry textbooks generally tell us that we can’t turn fatty acids into glucose. For example, on page 634 of the 2006 and 2008 editions of Biochemistry by Berg, Tymoczko, and Stryer, we find the following: Animals Cannot Convert Fatty Acids to Glucose It is important to note that animals are unable to effect the net synthesis of glucose from fatty acids. Specficially, acetyl CoA cannot be converted into pyruvate or oxaloacetate in animals. In fact this is so important that it should be written in italics and have its own bold heading! But it’s not quite right. Making glucose from fatty acids is low-paying work. It’s not the type of alchemy that would allow us to build imperial palaces out of sugar cubes or offer hourly sweet sacrifices upon the altar of the glorious god of glucose (God forbid!). But it can be done, and it’ll help pay the bills when times are tight. All Aboard the Acetyl CoA! When we’re running primarily on fatty acids, our livers break the bulk of these fatty acids down into two-carbon units called acetate. When acetate hangs out all by its lonesome like it does in a bottle of vinegar, it’s called acetic acid and it gives vinegar its characteristic smell. Our livers aren’t bottles of vinegar, however, and they do things a bit differently. They have a little shuttle called coenzyme A, or “CoA” for short, that carries acetate wherever it needs to go. When the acetate passenger is loaded onto the CoA shuttle, we refer to the whole shebang as acetyl CoA. As acetyl CoA moves its caboose along the biochemical railway, it eventually reaches a crossroads where it has to decide whether to enter the Land of Ketogenesis or traverse the TCA cycle. The Land of Ketogenesis is a quite magical place to which we’ll return in a few moments, but n Continue reading >>
- International Textbook of Diabetes Mellitus, 4th Ed., Excerpt #82: Insulin Actions In Vivo: Glucose Metabolism Part 9 of 9
- World's first diabetes app will be able to check glucose levels without drawing a drop of blood and will be able to reveal what a can of coke REALLY does to sugar levels
- International Textbook of Diabetes Mellitus, 4th Ed., Excerpt #59: Mechanisms of insulin signal transduction Part 3 of 8
Carbohydrates, Proteins, And Fats
Carbohydrates, proteins, and fats supply 90% of the dry weight of the diet and 100% of its energy. All three provide energy (measured in calories), but the amount of energy in 1 gram (1/28 ounce) differs: These nutrients also differ in how quickly they supply energy. Carbohydrates are the quickest, and fats are the slowest. Carbohydrates, proteins, and fats are digested in the intestine, where they are broken down into their basic units: The body uses these basic units to build substances it needs for growth, maintenance, and activity (including other carbohydrates, proteins, and fats). Carbohydrates Depending on the size of the molecule, carbohydrates may be simple or complex. Simple carbohydrates: Various forms of sugar, such as glucose and sucrose (table sugar), are simple carbohydrates. They are small molecules, so they can be broken down and absorbed by the body quickly and are the quickest source of energy. They quickly increase the level of blood glucose (blood sugar). Fruits, dairy products, honey, and maple syrup contain large amounts of simple carbohydrates, which provide the sweet taste in most candies and cakes. Complex carbohydrates: These carbohydrates are composed of long strings of simple carbohydrates. Because complex carbohydrates are larger molecules than simple carbohydrates, they must be broken down into simple carbohydrates before they can be absorbed. Thus, they tend to provide energy to the body more slowly than simple carbohydrates but still more quickly than protein or fat. Because they are digested more slowly than simple carbohydrates, they are less likely to be converted to fat. They also increase blood sugar levels more slowly and to lower levels than simple carbohydrates but for a longer time. Complex carbohydrates include starches and fib Continue reading >>
Ann L. Albright and Judith S. Stern Department of Nutrition and Internal Medicine University of California at Davis Davis, CA USA Morphology and Development of Adipose TissueAdipose-Tissue MetabolismAdipose Tissue DistributionDefinition and Causes of ObesityFurther Reading Albright, A.L. and Stern, J.S. (1998). Adipose tissue. In: Encyclopedia of Sports Medicine and Science, T.D.Fahey (Editor). Internet Society for Sport Science: 30 May 1998. Adipose tissue is specialized connective tissue that functions as the major storage site for fat in the form of triglycerides. Adipose tissue is found in mammals in two different forms: white adipose tissue and brown adipose tissue. The presence, amount, and distribution of each varies depending upon the species. Most adipose tissue is white, the focus of this review. White adipose tissue serves three functions: heat insulation, mechanical cushion, and most importantly, a source of energy. Subcutaneous adipose tissue, found directly below the skin, is an especially important heat insulator in the body, because it conducts heat only one third as readily as other tissues. The degree of insulation is dependent upon the thickness of this fat layer. For example, a person with a 2-mm layer of subcutaneous fat will feel as comfortable at 15°C as a person with a 1-mm layer at 16°C. Adipose tissue also surrounds internal organs and provides some protection for these organs from jarring. As the major form of energy storage, fat provides a buffer for energy imbalances when energy intake is not equal to energy output. It is an efficient way to store excess energy, because it is stored with very little water. Consequently, more energy can be derived per gram of fat (9 kcal.gm-1) than per gram of carbohydrate (4 kcal.gm-1) or protein (4 kcal.g Continue reading >>
Lecture 14: Introduction To Metabolic Regulation
Lecture 14: Introduction to metabolic regulation If you lose the printed handout, you can download another copy here. The "purpose" of metabolism is to supply the energy and raw materials that the body needs to stay alive and reproduce. Not only must these systems operate efficiently in "ideal" situations, but they must also handle shortages and unexpected demands: fighting, natural disasters, pregnancy, lactation, famine, injury and disease. Metabolic control mechanisms are complex, but they normally work very well. They are essential for survival. 1) It is of central importance to keep blood glucose close to 5mM. This is essential for normal cerebral functions. The brain can and does use other fuels, such as ketones and amino acids, but only glucose can cross the blood-brain barrier in sufficient quantities to support normal activity. Confusion and coma supervene if blood glucose falls below 3mM, serious vascular damage follows through protein glycation if it exceeds 8mM for significant periods. Long-term damage caused by protein glycation includes ulcers, kidney failure, blindness, strokes and ischaemic heart disease. Glycation is the non-enzymatic condensation of the aldehyde and ketone groups in sugars with amino groups in proteins to initially yield Schiff bases. These then undergo further chemical reactions to produce "advanced glycation end products" or AGEs. Kumar & Clarke rather confusingly call this process "glycosylation" in chapter 19. Strictly speaking this term is not chemically accurate, but it is widely used. Glycation damages collagen in blood vessel walls, increasing their stiffness, and leading to inflammation and atherosclerosis. This process is now considered to be the major contributor to diabetic pathology, and this has resulted in greater clini Continue reading >>
26.6: The Catabolism Of Fats
To describe the reactions needed to completely oxidize a fatty acid to carbon dioxide and water. Like glucose, the fatty acids released in the digestion of triglycerides and other lipids are broken down in a series of sequential reactions accompanied by the gradual release of usable energy. Some of these reactions are oxidative and require nicotinamide adenine dinucleotide (NAD+) and flavin adenine dinucleotide (FAD). The enzymes that participate in fatty acid catabolism are located in the mitochondria, along with the enzymes of the citric acid cycle, the electron transport chain, and oxidative phosphorylation. This localization of enzymes in the mitochondria is of the utmost importance because it facilitates efficient utilization of energy stored in fatty acids and other molecules. Fatty acid oxidation is initiated on the outer mitochondrial membrane. There the fatty acids, which like carbohydrates are relatively inert, must first be activated by conversion to an energy-rich fatty acid derivative of coenzyme A called fatty acyl-coenzyme A (CoA). The activation is catalyzed by acyl-CoA synthetase. For each molecule of fatty acid activated, one molecule of coenzyme A and one molecule of adenosine triphosphate (ATP) are used, equaling a net utilization of the two high-energy bonds in one ATP molecule (which is therefore converted to adenosine monophosphate [AMP] rather than adenosine diphosphate [ADP]): The fatty acyl-CoA diffuses to the inner mitochondrial membrane, where it combines with a carrier molecule known as carnitine in a reaction catalyzed by carnitine acyltransferase. The acyl-carnitine derivative is transported into the mitochondrial matrix and converted back to the fatty acyl-CoA. Further oxidation of the fatty acyl-CoA occurs in the mitochondrial matrix vi Continue reading >>
Ketogenic Amino Acid
All mammals synthesize saturated fatty and monounsaturated fatty acids de novo from simple precursors such as glucose or ketogenic amino acids. However, mammals cannot insert double bonds more proximal to the methyl end than the ninth carbon atom. Thus, two fatty acids having their first double bonds at the 6th and 3rd carbon atoms, namely, linoleic (18:2 n-6) and alpha-linolenic acid (18:3 n-3), respectively, cannot be synthesized de novo. Therefore, these fatty acids have to be supplied through the diet and are called essential fatty acids. Denoting the position of the first double bond proximal to the methyl end of the fatty acid chain, essential fatty acids are also classified as omega-6 (n-6) and omega-3 (n-3) fatty acids. A list of the most common n-3 and n-6 fatty acids and their systemic, common name, and shorthand notation is shown in Table 28.1. As early as the1930s, the essentiality of linoleic acid (18:2 n-6) and alpha-linolenic acid (18:3 n-3) in rat diets was identified (Burr and Burr, 1930). However, the essentiality of n-3 fatty acids in humans was first demonstrated only in the early 1980s (Holman et al., 1982). M. Saleet Jafri*, Rashmi Kumar, in Progress in Molecular Biology and Translational Science , 2014 One of the primary functions of the mitochondria is catabolic energy metabolism; that is, substrates, such as carbohydrates, fatty acids, and proteins, are broken down to release energy that is stored in high-energy phosphate bonds in molecules such as ATP and CP (creatine phosphate). This occurs in multiple stages by multiple pathways. (1) The tricarboxylic acid (TCA) cycle breaks down small carbohydrates (acetyl-CoA and TCA cycle intermediates) to produce reducing equivalents, that store the released energy. (2) There are also pathways that bring Continue reading >>
Metabolic Pathways From Glucose And Gln To Pa. Glucose Is Converted...
Phosphatidic acid (PA) has many diverse roles in cell physiology. Most significantly, PA is at the center of membrane phospholipid biosynthesis (Fig. 1), and as a consequence, the level of PA is carefully controlled to maintain lipid homeostasis (1, 2). In addition, PA has emerged as a critical factor for several key signaling molecules that regulate cell cycle progression and survival, including the protein kinases mTOR (mammalian/ mechanistic target of rapamycin) (3) and Raf (4). Of significance, both mTOR and Raf have been implicated in human cancer. Consistent with this emerging role for PA in regulating cell proliferation, elevated expression and/or activity of enzymes that generate PA is commonly observed in human cancer, most notably phospholipase D (PLD) (5, 6), which is elevated especially in K-Ras-driven cancers (79). Other enzymes that generate PA (lysophosphatidic acid (LPA) acyltransferase (LPAAT), and diacylglycerol (DG) kinase (DGK) (Fig. 1)) have also been implicated in human cancers (10 14). Importantly, LPAAT and DGK have been shown to stimulate mTOR (14 17), reinforcing the importance of the PA-mTOR axis in the control of cell growth and proliferation. Moreover, there appears to be compensatory production of PA under stressful conditions where one source of PA is compromised (7, 18). The LPAAT pathway, which is an integral part of the de novo pathway for biosynthesis of membrane phospholipids, is likely the most significant source of PA for lipid biosynthesis. However, growth factors (6) and nutrients (19, 20) also stimulate PA production through the action of phospholipases that break- down membrane phospholipids, potentially leading to high PA concentrations at specific locations and times. This can be accomplished by PLD, or a combination of phosp Continue reading >>
- Diet Soda Intake and Risk of Incident Metabolic Syndrome and Type 2 Diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA)*
- Ultraviolet Radiation Suppresses Obesity and Symptoms of Metabolic Syndrome Independently of Vitamin D in Mice Fed a High-Fat Diet
- Why Diabetes Is Dangerous: How to Recognize the Signs of this Metabolic Disease
In Silico Evidence For Gluconeogenesis From Fatty Acids In Humans
In Silico Evidence for Gluconeogenesis from Fatty Acids in Humans 2Systems Biology/Bioinformatics Group, Leibniz Institute for Natural Product Research and Infection Biology Hans Knll Institute, Jena, Germany 3Department of Human Nutrition, Institute of Nutrition, University of Jena, Jena, Germany 4Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbrcke, Nuthetal, Germany 1Department of Bioinformatics, School of Biology and Pharmaceutics, Friedrich Schiller University of Jena, Jena, Germany 2Systems Biology/Bioinformatics Group, Leibniz Institute for Natural Product Research and Infection Biology Hans Knll Institute, Jena, Germany 3Department of Human Nutrition, Institute of Nutrition, University of Jena, Jena, Germany 4Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbrcke, Nuthetal, Germany Stanford University, United States of America Conceived and designed the experiments: CK RG MR SS. Analyzed the data: CK LFdF SW. Wrote the paper: CK LFdF SS. Received 2011 Jan 14; Accepted 2011 May 24. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. This article has been cited by other articles in PMC. The question whether fatty acids can be converted into glucose in humans has a long standing tradition in biochemistry, and the expected answer is No. Using recent advances in Systems Biology in the form of large-scale metabolic reconstructions, we reassessed this question by performing a global investigation of a genome-scale human metabolic network, which had been reconstructed on the basis of experimental results. By elem Continue reading >>
Overview Carbohydrates, fats and proteins are macronutrients. We require them in relatively large amounts for normal function and good health. These are also energy-yielding nutrients, meaning these nutrients provide calories. On This Page: What are Carbohydrates? Carbohydrates Understanding Carbohydrates Every few years, carbohydrates are vilified as public enemy number one and are accused of being the root of obesity, diabetes, heart disease and more. Carb-bashers shun yogurt and fruit and fill up on bun-less cheeseburgers. Instead of beans, they eat bacon. They dine on the tops of pizza and toss the crusts into the trash. They so vehemently avoid carbs and spout off a list of their evils that they may have you fearing your food. Rest assured, you can and should eat carbohydrates. In fact, much of the world relies on carbohydrates as their major source of energy. Rice, for instance, is a staple in Southeast Asia. The carbohydrate-rich potato was so important to the people of Ireland that when the blight devastated the potato crop in the mid 1800s, much of the population was wiped out. What are Carbohydrates? The basic structure of carbohydrates is a sugar molecule, and they are classified by how many sugar molecules they contain. Simple carbohydrates, usually referred to as sugars, are naturally present in fruit, milk and other unprocessed foods. Plant carbohydrates can be refined into table sugar and syrups, which are then added to foods such as sodas, desserts, sweetened yogurts and more. Simple carbohydrates may be single sugar molecules called monosaccharides or two monosaccharides joined together called disaccharides. Glucose, a monosaccharide, is the most abundant sugar molecule and is the preferred energy source for the brain. It is a part of all disaccharides Continue reading >>
Carbohydrate, Protein And Lipid Metabolism Notes
Part 1 – Metabolism Concepts and Measurement Carbohydrates, protein and fat are macronutrients. In the human body metabolism is the oxidization of carbohydrates, protein and fat to give CO2, H2O and energy. What is Metabolic Rate? Metabolic Rate is the amount of energy liberated per unit time. The Basal Metabolic Rate is the rate of energy expenditure at rest in a neutrally temperate environment, in the post-absorptive state (meaning that the digestive system is inactive, which requires about twelve hours of fasting in humans). The Basal Metabolic Rate is the largest component of total caloric expenditure in humans: 70% Physical activity contributes: 20% Thermogenesis & digestion contributes: 10% Units used for Metabolic Energy calorie (cal – note lowercase) is the standard unit of metabolic heat energy, being the amount of energy needed to raise 1g of water by 1 degree, from 15o to 16o C. Calorie (kilocalorie, kcal, big calorie, large calorie, kilogram calorie) is more commonly used, representing 1000 calorie. Joule is the SI unit for energy, such that 1 calorie = 4.2 joule. To convert from Calories (kilocalories) to kilojoules, multiply by 4.2. How do we measure Metabolic Energy and Metabolic Rate? Direct calorimetry A Bomb Calorimeter, or constant-volume calorimeter, is used to measure the energy released by food during complete oxidization. The food is placed in a sealed metal container surrounded by water in an insulated container. The food is ignited by an electrical spark and the temperature change of a known volume of water is used to calculate the energy released by the food. Standard caloric values for macronutrients are: Carbohydrates: 4.1 kcal/g Protein: 5.3 kcal/g (but in the body is only 4.1 kcal/g due to incomplete oxidation) Fat: 9.3 kcal/g Ethanol: Continue reading >>
- Effect of Probiotics on Glucose and Lipid Metabolism in Type 2 Diabetes Mellitus: A Meta-Analysis of 12 Randomized Controlled Trials
- Pre-diabetes goes into remission on higher protein, lower carbohydrate diet (Zone diet balance)
- Impact of menopause and diabetes on atherogenic lipid profile: is it worth to analyse lipoprotein subfractions to assess cardiovascular risk in women?
Best Quality Construction Products For You!
So if you are already familiar with Cisco routers and TCP/IP, this may be a better solution for you. Finally, we recommend the Bryant Advantage Ultimate CCNA Study Package. 300-115If you want to pass your ICND1, ICND2 or CCNA exam on the first try, it is essential you have a sound, effective study plan that is proven and other Cisco CCNA students have followed to successfully pass their 200-120, 101-101, or 200-101 tests. We want to be very clear, just having routers, switches and a lab workbook is not enough to pass your Cisco exam. 210-260 pdfDHCP snooping and IP Source Guard have been configured on a switch that connects to several client workstations. The IP address of one of the workstations does not match any entries found in the DHCP binding database. Which statement describes the outcome of this scenario? A. Packets from the workstation will be rate limited according to the default values set on the switch. B. The interface that is connected to the workstation in question will be put into the errdisabled state. C. Traffic will pass accordingly after the new IP address is populated into the binding database. D. The packets originating from the workstation are assumed to be spoofed and will be discarded. We are providing the helping material in two ways which are PDF Practice Test Software PDF Exam - the first technique expected of applicants to prepare for CCNA Routing and Switching 200-125 Cisco Certified Network Associate, are hand notes that consist of full, comprehensive information about every CCNA Routing and Switching 200-125 Cisco Certified Network Associate area. 200-125 dumpsIt is written in laymans terms for very green students and it the cheapest solution. However I have found that it does not go as in-depth to some topics as I might like. Continue reading >>
What Are Ketone Bodies And Why Are They In The Body?
If you eat a calorie-restricted diet for several days, you will increase the breakdown of your fat stores. However, many of your tissues cannot convert these fatty acid products directly into ATP, or cellular energy. In addition, glucose is in limited supply and must be reserved for red blood cells -- which can only use glucose for energy -- and brain tissues, which prefer to use glucose. Therefore, your liver converts many of these fatty acids into ketone bodies, which circulate in the blood and provide a fuel source for your muscles, kidneys and brain. Video of the Day Low fuel levels in your body, such as during an overnight fast or while you are dieting, cause hormones to increase the breakdown of fatty acids from your stored fat tissue. These fatty acids travel to the liver, where enzymes break the fatty acids into ketone bodies. The ketone bodies are released into the bloodstream, where they travel to tissues that have the enzymes to metabolize ketone bodies, such as your muscle, brain, kidney and intestinal cells. The breakdown product of ketone bodies goes through a series of steps to form ATP. Conditions of Ketone Body Utilization Your liver will synthesize more ketone bodies for fuel whenever your blood fatty acid levels are elevated. This will happen in response to situations that promote low blood glucose, such as an overnight fast, prolonged calorie deficit, a high-fat and low-carbohydrate diet, or during prolonged low-intensity exercise. If you eat regular meals and do not typically engage in extremely long exercise sessions, the level of ketone bodies in your blood will be highest after an overnight fast. This level will drop when you eat breakfast and will remain low as long as you eat regular meals with moderate to high carbohydrate content. Ketone Bodi Continue reading >>
C2006/f2402 '11 Outline Of Lecture #16
Handouts: 15A -- Lining of the GI Tract & Typical Circuit 15B -- Homeostasis -- Seesaw view for Glucose and Temperature Regulation; 16 -- Absorptive vs Postabsorptive state I. Homeostasis, cont. See handouts 15A & B & notes of last time, topic VI. A. Regulation of Blood Glucose Levels -- Seesaw View #1 (Handout 15B) B. Regulation of Human Body Temperature -- Seesaw #2 (Handout 15B) C. The Circuit View (Handout 15A) II. Matching circuits and signaling -- an example: How the glucose circuit works at molecular/signaling level Re-consider the circuit or seesaw diagram for homeostatic control of blood glucose levels -- what happens in the boxes on 15A? It may help to refer to the table below. A. How do Effectors Take Up Glucose? 1. Major Effectors: Liver, skeletal muscle, adipose tissue 2. Overall: In response to insulin, effectors increase both uptake & utilization of glucose. Insulin triggers one or more of the following in the effectors: a. Causes direct increase of glucose uptake by membrane transporters b. Increases breakdown of glucose to provide energy c. Increases conversion of glucose to 'stores' (1). Glucose is converted to storage forms (fat, glycogen), AND (2). Breakdown of storage fuel molecules (stores) is inhibited. d. Causes indirect increase of glucose uptake by increasing phosphorylation of glucose to G-P, trapping it inside cells 3. How does Insulin Work? a. Receptor: (1). Insulin works through a special type of cell surface receptor, a tyrosine kinase linked receptor; See Sadava fig. 7.7 (15.6). Insulin has many affects on cells and the mechanism of signal transduction is complex (activating multiple pathways). (2). In many ways, insulin acts more like a typical growth factor than like a typical endocrine. (Insulin has GF-like effects on other cells; is i Continue reading >>