Glycogen Metabolism
Glycogen is a readily mobilized storage form of glucose. It is a very large, branched polymer of glucose residues (Figure 21.1) that can be broken down to yield glucose molecules when energy is needed. Most of the glucose residues in glycogen are linked by α-1,4-glycosidic bonds. Branches at about every tenth residue are created by α-1,6-glycosidic bonds. Recall that α-glycosidic linkages form open helical polymers, whereas β linkages produce nearly straight strands that form structural fibrils, as in cellulose (Section 11.2.3). Glycogen is not as reduced as fatty acids are and consequently not as energy rich. Why do animals store any energy as glycogen? Why not convert all excess fuel into fatty acids? Glycogen is an important fuel reserve for several reasons. The controlled breakdown of glycogen and release of glucose increase the amount of glucose that is available between meals. Hence, glycogen serves as a buffer to maintain blood-glucose levels. Glycogen's role in maintaining blood-glucose levels is especially important because glucose is virtually the only fuel used by the brain, except during prolonged starvation. Moreover, the glucose from glycogen is readily mobilized and is therefore a good source of energy for sudden, strenuous activity. Unlike fatty acids, the released glucose can provide energy in the absence of oxygen and can thus supply energy for anaerobic activity. The two major sites of glycogen storage are the liver and skeletal muscle. The concentration of glycogen is higher in the liver than in muscle (10% versus 2% by weight), but more glycogen is stored in skeletal muscle overall because of its much greater mass. Glycogen is present in the cytosol in the form of granules ranging in diameter from 10 to 40 nm (Figure 21.2). In the liver, glycoge Continue reading >>
Chapter 25 - Metabolism And Nutrition Flashcards Preview
One glucose molecule is oxidized and it produces two molecules of pyruvic acid, two molecules of ATP and two (NADH + H+) What happens during the formation of acetyl coenzyme A? Pyruvic acid is prepared for entrance into the Krebs cycle - also produces energy-containing NADH + H+ and carbon dioxide What happens during the Krebs cycle reaction? Oxidize acetyl co enzyme A and produces carbon dioxide, ATP, NADH + H+ and FADH2 What happens during the electron transport chain reaction? NADH + H+ and FADH2 are oxidized, and transfer their electrons through a series of electron carriers What are the two sets of reaction that require oxygen during cellular respiration? - converts pyruvic acid to a 2-carbon fragment called an acetyl group - a series of oxidation-reduction reactions and decarboxylation reactions release CO2 Where does the electron transport chain reaction occur? What is the overall reaction of cellular respiration? Glucose (C6H12O6) + 6 oxygen molecules (6O2) + 36 or 38 Phosphate groups + 36 or 38 ADP --> 6 carbon dioxide molecules (6CO2) + 6 water + 36 or 38 ATP! What happens if glucose is not needed immediately? What does it get made into? Combines with other molecules to form glycogen Must be present in the diet, b/c we cannot create them What is happening during the absorptive state? Ingested nutrients are entering the bloodstream and glucose is readily available for ATP production What happens during the post-absorptive state? Absorption of nutrients from GI tract is complete - energy needs must be met by fuels in the body 1. 50% of absorbed glucose used to produce ATP (glycolysis, Krebs cycle and electron transport chain) 2. Glucose is converted to glycogen (in hepatocytes) 3. Hepatocytes package most fatty acids and triglycerides to adipose tissue for stor Continue reading >>
Overcoming Diabetes: The Complete Complementary Health Program
Overcoming Diabetes: The Complete Complementary Health Program 0 Reviews This unique book - one in a series of natural health guides from doctor and internationally bestselling author Sarah Brewer - provides a highly authoritative yet easy-to-follow program of complementary medicine and self-care treatments for this increasingly prevalent condition. If you are one of the millions with Diabetes, and are looking for expert advice on the steps you can take to alleviate your symptoms and enhance health and well-being, this is the book for you. Part One helps you to understand your condition, offering an insightful overview of diagnosis, monitoring and treatment, and explaining the differences between type 1 and type 2 diabetes. Part Two guides you through the many complementary and nutritional approaches to treatment, such as reflexology, acupuncture and magnetic therapy, plus the benefits of including good fats and superfoods in your diet. It also reveals how controlling your carb intake, cutting down on salt, and maintaining a healthy weight can transform how your body responds to your condition. Finally, in Part Three of this groundbreaking book, Dr Sarah Brewer offers a pioneering approach of tailor-made programs, based on the premise that we're all unique, and have different requirements depending on our age, gender, lifestyle and genetic background. Choose from The Gentle Program, The Moderate Program or The Full-strength Program - each guiding you through nutritional plans, exercise routines and therapeutic techniques - all of which empower you to take control and make real changes to your health and your life.
3 What Are The Possible Fates Of Glucose In The Body What Is The Protein
3 What are the possible fates of glucose in the body What is the protein 3 what are the possible fates of glucose in the body This preview shows page 1 - 3 out of 4 pages. oxygen atom splits causing the molecule to separate into, forming two monosaccharides. 3. What are the possible fates of glucose in the body? What is the protein sparing action of carbohydrate?Glucose can be converted by the liver into a long chain molecule called glycogen and stored for a few hours until blood sugar falls again.If needed, glucose can be broken down into carbon dioxide and water, and used immediately as energy for cells in glycolysis.When blood sugar falls and glycogen stores are depleted, the body can make glucose from protein in a process called gluconeogenesis. The root word is genesis (meaning-beginning of origin) because the body makes new glucose. 4. Which of the following is a feature of glycogen?a. It is found in plantsb. It is important as a dietary nutrientc. It is virtually absent from animal meatsd. It plays an insignificant role in the bodyANSWER: B5. Which of the following statements is not characteristic of fibers?6. Which of the following is a typical response of the body to changes in blood glucose? Chapter 5 The Lipids: Triglycerides, Phospholipids, and Sterols1. Continue reading >>
What Are The Three Main Steps Of Aerobic Glucose Metabolism?
What are the three main fates of glucose? What are the three main fates of glucose? Would you like to merge this question into it? already exists as an alternate of this question. Would you like to make it the primary and merge this question into it? Answers.com is making the world better one answer at a time. Immediate use to produce ATP molecules,storage for later ATPproduction,or for use in building other molecules. Immediate use to produce ATP molecules,storage for later ATPproduction,or for use in building other molecules. What are three fates and the job of each? There was Clotho who spun the thread of life from her distaff onto her spindle, Lachesis who measured the thread of life with her rod, and Athropos who was the cutter of the thread of life and chose the manner of a person's death. The Three Fates are the keepers of life, servants of Hades, god of the underworld. They decide when someone dies. Each person has a life line, a string that the fates control. When the fates cut that string that person's life line end, or in other words, they die. When than person dies they go to the underworld, ruled by Hades. ''I would be loath to cast away my speech, for besides that it is excellently well penned, I have taken great pains to con it.'' - W. S. Who were the three fates in roman mythology? Nona (Greek equivalent Clotho ), who spun the thread of life from her distaff onto her spindle; . Decima (Greek Lachesis ), who measured the thread of life with her rod; . Morta (Greek Atropos ), who cut the thread of life and chose the manner of a person's death There are three main steps, often referred to as phases, that takeplace during aerobic glucose metabolism. These phases include sugaractivation, sugar cleavage, and then sugar oxidation. Clotho spun the thread, Lache Continue reading >>
Hey What Are The Three Possible Fates Of The Glucose Produced In Photosynthesis? | Yahoo Answers
Hey what are the three possible fates of the glucose produced in photosynthesis? Are you sure you want to delete this answer? Best Answer: Just wanted to say that for the previous answer by Krupkake, cellular respiration and converting into ATP are the same thing. -Cellular respiration with the release of carbon dioxide, water and heat Cellular respiration, turning into ATP, or Stored as fat I think this question violates the Community Guidelines Chat or rant, adult content, spam, insulting other members, show more I think this question violates the Terms of Service Harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing, show more If you believe your intellectual property has been infringed and would like to file a complaint, please see our Copyright/IP Policy I think this answer violates the Community Guidelines Chat or rant, adult content, spam, insulting other members, show more I think this answer violates the Terms of Service Harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing, show more If you believe your intellectual property has been infringed and would like to file a complaint, please see our Copyright/IP Policy I think this comment violates the Community Guidelines Chat or rant, adult content, spam, insulting other members, show more I think this comment violates the Terms of Service Harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing, show more If you believe your intellectual property has been infringed and would like to file a complaint, please see our Copyright/IP Policy Upload failed. Please upload a file larger than 100x100 pixels We are experien Continue reading >>
Digestion, Absorption And Transport Of Carbohydrates
Sign up to our newsletter Receive the latest newsletter with research on sugar. Plus insights from scientific experts. Carbohydrates are broken down to provide glucose for energy Digestion predominantly occurs via enzymes lining the wall of the small intestine Once absorbed, galactose and fructose are metabolised further by the liver to produce glucose and minimal amounts of other metabolites ___________________ The metabolism of carbohydrates is the process of getting the carbohydrates in the foods we eat into the right format to provide fuel to our body's cells. This process involves digestion, absorption and transportation. Most commonly, carbohydrate metabolism results in the production of glucose molecules which are the most efficient source of energy (ATP) for our muscles and our brains. Energy or fuel from our food is used for cell growth, repair and normal cell functioning. Digestion Carbohydrates are most commonly consumed as polysaccharides (e.g. starch, fibre or cellulose) or disaccharides (e.g. lactose, sucrose, galactose) and therefore need to be broken down into their simpler monosaccharide forms which the body can utilise. The digestion process of polysaccharides such as starch will begin in the mouth where it is hydrolysed by salivary amylase. The amount of starch hydrolysed in this environment is often quite small as most food does not stay in the mouth long. Once the food bolus reaches the stomach the salivary enzymes are denatured. As a result, digestion predominantly occurs in the small intestine with pancreatic amylase hydrolysing the starch to dextrin and maltose. Enzymes classed as glucosidases on the brush border of the small intestine break down the dextrin and maltase, lactase and sucrase convert the other disaccharides into their two monosacch Continue reading >>
Glucose 6-phosphatase
Not to be confused with Glucose-6-phosphate dehydrogenase . Glucose 6-phosphatase ( EC 3.1.3.9 , G6Pase) is an enzyme that hydrolyzes glucose-6-phosphate , resulting in the creation of a phosphate group and free glucose. Glucose is then exported from the cell via glucose transporter membrane proteins . [1] This catalysis completes the final step in gluconeogenesis and therefore plays a key role in the homeostatic regulation of blood glucose levels. [2] Glucose-6-phosphatase is a complex of multiple component proteins, including transporters for G6P, glucose, and phosphate. The main phosphatase function is performed by the glucose-6-phosphatase catalytic subunit. In humans, there are three isozymes of the catalytic subunit: glucose-6-phosphatase-, encoded by G6PC ; IGRP, encoded by G6PC2 ; and glucose-6-phosphatase-, encoded by G6PC3 . [3] Glucose-6-phosphatase- and glucose-6-phosphatase- are both functional phosphohydrolases, and have similar active site structure, topology, mechanism of action, and kinetic properties with respect to G6P hydrolysis. [4] In contrast, IGRP has almost no hydrolase activity, and may play a different role in stimulating pancreatic insulin secretion. [5] Vanadium containing chloroperoxidase enzyme with amino acid residues shown in color. Vanadium containing chloroperoxidase has a similar structure and active site as glucose-6-phosphatase.(From pdb 1IDQ) Position of active site amino acid residues of vanadium containing chloroperoxidase shown in relation to enzyme surface.(From pdb 1IDQ) The active site of vanadium containing chloroperoxidase. The residues Lys353, Arg360, Arg490, His404, and His496 correspond to Lys76, Arg83, Arg170, His119, and His176 in Glc 6-Pase. (From pdb 1IDQ) Although a clear consensus has not been reached, a large num Continue reading >>
- Exercise and Glucose Metabolism in Persons with Diabetes Mellitus: Perspectives on the Role for Continuous Glucose Monitoring
- Postprandial Blood Glucose Is a Stronger Predictor of Cardiovascular Events Than Fasting Blood Glucose in Type 2 Diabetes Mellitus, Particularly in Women: Lessons from the San Luigi Gonzaga Diabetes Study
- Exercise and Blood Glucose Levels
Introduction To The Degradation And The Synthesis Of Glucose
Content: 1. Introduction to the degradation and the synthesis of glucose 2. Glycolysis 3. Gluconeogenesis _ Saccharides are one of the main nutrients for heterotrophic organisms. Saccharides can be found in each cell of the human body. Saccharides have many different functions: (1) source of energy, (2) source of carbon atoms for syntheses, (3) reserves of energy (glycogen), (4) structural function (proteoglycans). Glucose (Glc) is universal energetic substrate. One gram of glucose when oxidized provides 17 kJ (= 4 kcal). Of great importance is fact that our cells are capable of draining energy from glucose even in anaerobic conditions – this is not true for any other nutrient we use. There are some populations of cells that are strictly dependent on glucose – i.e. erythrocytes, cells of central nervous system, etc…. We would like to emphasize that pyruvate dehydrogenase reaction (PDH) is irreversible therefore it is not possible to synthesise glucose from fatty acids. Au contraire our cells are capable of converting excessive glucose into fatty acids and then into TAG. Glucose blood concentration is called glycemia. Glycemia is normally 3,3 – 5,6 mmol/l, glycemia can after a meal increase to 7,0 mmol/l. In physiological conditions glucose is not present in the urine. In case that glycemia is higher than 10,0 mmol/l the renal threshold is exceeded and glucose gets into the urine. This condition is called glycosuria. Thus when glycemia is higher than renal threshold (value of threshold is 10,0 mmol/l) glucose can be found in the urine. In the food is glucose in several forms: (1) free glucose, (2) part of oligosaccharides (predominantly disaccharides), and (3) part of polysaccharides. To the blood is from intestine released only free glucose. Sources of blood glu Continue reading >>
- Introduction to Type I Diabetes
- Exercise and Glucose Metabolism in Persons with Diabetes Mellitus: Perspectives on the Role for Continuous Glucose Monitoring
- Postprandial Blood Glucose Is a Stronger Predictor of Cardiovascular Events Than Fasting Blood Glucose in Type 2 Diabetes Mellitus, Particularly in Women: Lessons from the San Luigi Gonzaga Diabetes Study
More Into Photosynthesis
a purine base (adenine), a pentose sugar (ribose), and three phosphate groups acts as a store of energy within the cell. The bonds between phosphate groups contain high-energy electrons, and store a large amount of energy that is released during a chemical reaction What happens when you remove a phosphate group from ATP the bonds between the phosphate groups of ATP are unstable and very little energy is needed to break them. The energy in the ATP molecule is transferred to a target molecule (e.g) protein by a hydrolysis reaction. Water is split during the reaction and added to the terminal phosphate on ATP, forming ADP and an inorganic phosphate molecule (pi) why does conversion of ATP to ADP keep us warm When the Pi molecule combines with a target molecule, energy is released. Most of this energy (about 60%) is lost as heat. The rest of the energy is transferred to the target molecule , allowing it to do work, like joining with another molecule light dependent reactions and light independent cycles light energy is converted to chemical energy (ATP and NADPH) this phase occurs in the thylakoid membranes of the chloroplasts the chemical energy is used to synthesize carbohydrate. This phase occurs in the stroma of chloroplasts in the first phase of photosynthesis, chlorophyll captures loght energy which is used to split water, producing O2 gas (waste) and H+ ions that are transferred to the molecule NADPH. ATP is also produced. The light dependent phase occurs in the thylakoid membrane of the grana. the second phase of photosynthesis occurs in the stroma and uses the NADPH and the ATP to drive a series of enzyme-controlled reactions (the calvin cycle) that fix carbon dioxide to produce triose phosphate. This phase does not need light to proceed immediate use to produce u Continue reading >>
Tributes To Energy Production By Entering Glycolysis As Dihydroxyacetone Phosphate.
25.6 The Key Intermediate-Acetyl CoA 77t 25.6 The key intermediote-acetyl CoA AIMS: To name the shored intermediote of both carbohydrote ond fotty ocid metobolism, To list four fotes of ocetyl CoA in the liver. Now that we have seen how the body oxidizes fatty acids, we can form an overall picture of the various parts of fatty acid metabolism. We can exam- ine the relationships between carbohydrate metabolism and fatty acid metabolism at the same time. Since the liver conducts more carbohydrate metabolism and fatty acid metabolism than any other organ, this discus- sion will focus on it. Figure 25.4 shows the relationships we will be examining in the remain- der of this chapter. Refer to it often as you read on. The figure shows that Focus Fatty acid metabolism and carbohydrate metabolism intersect at acetyl CoA. Figure 25.4 The major pathways of lipid metab- olism in the liver and their relation- ship to carbohydrate metabolism. Converting carbohydrates to fatty acids is an efficient way to store energy. fatty acids entering the liver from the blood may be reslmthesized into triglycerides and stored in the adipose tissue there. Alternatively, fatty acids may be broken do',nm to aceryl CoA. Glucose is also broken do',nm to acetyl CoA. If you are beginning to suspect that aceryl CoA must be a key com- pound in the metabolic interplay between carbohydrate and fatty acid metabolism, you are certainly correct. Four possible fates await the acetyl CoA produced from fatty acids or glucose in the liver: 1. The acetyl CoA in the mitochondria may be oxidized to carbon dioxide and water in the citric acid cycle and respiration. This pathway, which is used if the liver cells need to generate energy through respiration, makes it clear that the citric acid cycle is shared by both gl Continue reading >>
What Happens When Glucose Enters A Cell?
The process by which glucose is broken down in animal cells to pyruvate and energy is called glycolysis. The energy released in the conversion allows cells to make adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH), which can transport the energy anywhere it is needed. Enzymes then break down the ATP or NADH to provide energy to specific parts of the cell. The whole process involves about ten different chemical reactions. In the first half of the reactions, energy is used, but by the end of the process, the lost energy is replaced and doubled. Phosphorylation The first thing a cell does with the glucose when it enters is to prevent it from leaking back out through the cell membrane. The process is called phosphorylation, and it just involves a hexokinase enzyme converting the glucose to glucose 6-phosphate and then converting that into fructose 6-phosphate with the enzyme glucose phosphate isomerase. Conslidation A consolidating process takes place next. With the introduction of the enzymes phosphofructokinase 1 and pyrophosphate dependent phosphofructokinase, the fructose 6-phosphate is converted to Fructose 1,6-bisphosphate. Because this reaction happens so easily in the cell, it is difficult for the process to reverse. It is like a pumping station; it keeps the glycolysis process moving forward. Splitting With the introduction of the enzyme aldolase, the fructose 1,6-bisphosphate is split into two triose sugars, glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. Because the sugars are needed in different quantities at times, cells produce an enzyme, triosephosphate isomerase, which allows cells to convert either one into the other. Storing Energy Again Most of the previous reactions require energy to take place. From this point Continue reading >>
Glucose-6-phosphate - Encyclopedia Article - Citizendium
Glucose-6-phosphate, often abbreviated as G6P, is glucose that has been phosphorylated on carbon 6. The conversion from glucose to G6P is the first step of glycolysis for energy production in cells . This compound is very common in cells as the vast majority of glucose entering a cell will become phosphorylated in this way. Like glucose, it exists in linear and cyclic forms. Because if its prominent position in cellular chemistry, glucose-6-phosphate has many possible fates within the cell. It lies at the start of two major metabolic pathways , namely glycolysis and the pentose phosphate pathway . In addition to these metabolic pathways, glucose-6-phosphate may also be converted to glycogen or starch for storage. This storage is in the liver in the form of glycogen for most multicellular animals , and in intracellular starch or glycogen granules for most other organisms. The major reason for the immediate phosphorylation of glucose is to prevent diffusion out of the cell. The phosphorylation adds a charged phosphate group so that the glucose-6-phosphate cannot easily cross the cell membrane , in contrast to free glucose . Within a cell, glucose-6-phosphate is produced by phosphorylation of glucose on the sixth carbon. This is catalyzed by the enzyme hexokinase in most cells, and glucokinase in certain cells, most notably liver cells. One ATP is consumed in this reaction. Glucose-6-phosphate is also produced during glycogenolysis from glucose-1-phosphate , the first product of the breakdown of glycogen polymers. When the ratio of NADP+: NADPH increases, the body realizes it needs to produce more NADPH (a reducing agent for several reactions like fatty acid synthesis). This will cause the G6P to be dehydrogenated by glucose-6-phosphate dehydrogenase . This reversible rea Continue reading >>
Carbohydrate Metabolism
Carbohydrate metabolism denotes the various biochemical processes responsible for the formation, breakdown, and interconversion of carbohydrates in living organisms. Carbohydrates are central to many essential metabolic pathways.[1] Plants synthesize carbohydrates from carbon dioxide and water through photosynthesis, allowing them to store energy absorbed from sunlight internally.[2] When animals and fungi consume plants, they use cellular respiration to break down these stored carbohydrates to make energy available to cells.[2] Both animals and plants temporarily store the released energy in the form of high energy molecules, such as ATP, for use in various cellular processes.[3] Although humans consume a variety of carbohydrates, digestion breaks down complex carbohydrates into a few simple monomers for metabolism: glucose, fructose, and galactose.[4] Glucose constitutes about 80% of the products, and is the primary structure that is distributed to cells in the tissues, where it is broken down or stored as glycogen.[3][4] In aerobic respiration, the main form of cellular respiration used by humans, glucose and oxygen are metabolized to release energy, with carbon dioxide and water as byproducts.[2] Most of the fructose and galactose travel to the liver, where they can be converted to glucose.[4] Some simple carbohydrates have their own enzymatic oxidation pathways, as do only a few of the more complex carbohydrates. The disaccharide lactose, for instance, requires the enzyme lactase to be broken into its monosaccharide components, glucose and galactose.[5] Metabolic pathways[edit] Overview of connections between metabolic processes. Glycolysis[edit] Glycolysis is the process of breaking down a glucose molecule into two pyruvate molecules, while storing energy released Continue reading >>
Bbc - Gcse Bitesize: Photosynthesis
Photosynthesis captures energy for life on Earth. Many chemicals are made to allow life processes to occur in plants. These chemicals can move in and out of cells by the process of diffusion. Osmosis is a specific type of diffusion. Photosynthesis is a process used by plants in which energy from sunlight is used to convert carbon dioxide and water into molecules needed for growth. These molecules include sugars, enzymes and chlorophyll. Light energy is absorbed by the green chemical chlorophyll. This energy allows the production of glucose by the reaction between carbon dioxide and water. Oxygen is also produced as a waste product. This reaction can be summarised in the word equation: The chemical equation for photosynthesis is: Glucose is made up of carbon, hydrogen and oxygen atoms. Glucose made by the process of photosynthesis may be used in three ways: It can be converted into chemicals required for growth of plant cells such as cellulose It can be converted into starch, a storage molecule, that can be converted back to glucose when the plant requires it It can be broken down during the process of respiration, releasing energy stored in the glucose molecules Plants cells contain a number of structures that are involved in the process of photosynthesis: Diagram of a plant cell involved in production of glucose from photosynthesis Chloroplasts - containing chlorophyll and enzymes needed for reactions in photosynthesis. Nucleus - containing DNA carrying the genetic code for enzymes and other proteins used in photosynthesis Cell membrane - allowing gas and water to pass in and out of the cell while controlling the passage of other molecules Vacuole - containing cell sap to keep the cell turgid Cytoplasm - enzymes and other proteins used in photosynthesis made here Continue reading >>
