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The Body Can Make Glucose From Fatty Acids True Or False

We Really Can Make Glucose From Fatty Acids After All! O Textbook, How Thy Biochemistry Hast Deceived Me!

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 >>

Fsn127 E2

Fsn127 E2

Which is false about type 1 and type 2 diabetes ?A) when untreated they both cause hyperglycemiaB) initially, they both involve the failure of the pancreas to produce insulinC) they both are diseases relating to the control of blood glucose Flashcards Matching Hangman Crossword Type In Quiz Test StudyStack Study Table Bug Match Hungry Bug Unscramble Chopped Targets FSN127 Exam 2 Study Guide and Reading Assignment Question Answer Which is false about type 1 and type 2 diabetes ?A) when untreated they both cause hyperglycemiaB) initially, they both involve the failure of the pancreas to produce insulinC) they both are diseases relating to the control of blood glucose B) initially, they both involve the failure of the pancreas to produce insulin Which type of hypoglycemia occurs a few hours after a meal and is associated with a panic attack ? A) reactive hypoglycemia B) fasting hypoglycemia A) reactive hypoglycemia Which are signs that suggest a person should get evaluated for diabetes ?A) excessive hungerB) frequent urinationC) blurred visionD) A and B only E) A, B, and C E) A, B, and C It is possible that person who is classified as being insulin resistant will have a very high blood level of insulin. A) true B) false A) True All people who develop insulin resistance go on to develop Type 2 diabetes mellitus. A) true B) false B) False Various studies have shown that diabetics who consume food of low glycemic index tend to have improved blood glucose levels. A) true B) false A) True Hypoglycemia refers to A) high blood sugar B) high blood pressure C) low blood sugar D) low blood pressure C) Low blood sugar Which of the following refers to damage to the kidneys caused by chronic hyperglycemia, as occurs in poorly managed diabetes mellitus ?A) retinopathy B) neuropathy C) n Continue reading >>

The Inuit Paradox

The Inuit Paradox

Patricia Cochran, an Inupiat from Northwestern Alaska, is talking about the native foods of her childhood: “We pretty much had a subsistence way of life. Our food supply was right outside our front door. We did our hunting and foraging on the Seward Peninsula and along the Bering Sea. “Our meat was seal and walrus, marine mammals that live in cold water and have lots of fat. We used seal oil for our cooking and as a dipping sauce for food. We had moose, caribou, and reindeer. We hunted ducks, geese, and little land birds like quail, called ptarmigan. We caught crab and lots of fish—salmon, whitefish, tomcod, pike, and char. Our fish were cooked, dried, smoked, or frozen. We ate frozen raw whitefish, sliced thin. The elders liked stinkfish, fish buried in seal bags or cans in the tundra and left to ferment. And fermented seal flipper, they liked that too.” Cochran’s family also received shipments of whale meat from kin living farther north, near Barrow. Beluga was one she liked; raw muktuk, which is whale skin with its underlying blubber, she definitely did not. “To me it has a chew-on-a-tire consistency,” she says, “but to many people it’s a mainstay.” In the short subarctic summers, the family searched for roots and greens and, best of all from a child’s point of view, wild blueberries, crowberries, or salmonberries, which her aunts would mix with whipped fat to make a special treat called akutuq—in colloquial English, Eskimo ice cream. Now Cochran directs the Alaska Native Science Commission, which promotes research on native cultures and the health and environmental issues that affect them. She sits at her keyboard in Anchorage, a bustling city offering fare from Taco Bell to French cuisine. But at home Cochran keeps a freezer filled with fish Continue reading >>

Chapter Summary

Chapter Summary

Metabolism is the sum of all the chemical and physical processes by which the body breaks down and builds up molecules. All forms of life maintain a balance between anabolic and catabolic reactions, which determines if the body achieves growth and repair or if it persists in a state of loss. Metabolic pathways are clusters of chemical reactions that occur sequentially and achieve a particular goal, such as the breakdown of glucose for energy. These pathways are carefully controlled, either turned on or off, by hormones released within the body. Condensation and hydrolysis are chemical reactions involving water, whereas phosphorylation is a chemical reaction in which phosphate is transferred. In oxidation-reduction reactions, the molecules involved exchange electrons. Enzymes, coenzymes, and cofactors increase the efficiency of metabolism. Glucose oxidation occurs in three well-defined stages: glycolysis, the TCA cycle, and oxidative phosphorylation via the electron transport chain. The end products of glucose oxidation are carbon dioxide, water, and ATP. During glycolysis, six-carbon glucose is converted into two molecules of three-carbon pyruvate. If glycolysis is anaerobic, this pyruvate is converted to lactic acid. If glycolysis is aerobic, this pyruvate is converted to acetyl CoA and enters the TCA cycle. During the TCA cycle, acetyl CoA coming from either carbohydrate,fat, or protein metabolism results in the production of GTP or ATP, NADH, and FADH2. These two final compounds go through oxidative phosphorylation (as part of the electron transport chain) to produce energy. During oxidative phosphorylation, the NADH and the FADH2 enter the electron transport chain where, through a series of reactions, ATP is produced. Triglycerides are broken down into glycerol and Continue reading >>

Can Amino Acids Be Used By The Body To Make Glucose & Fatty Acids?

Can Amino Acids Be Used By The Body To Make Glucose & Fatty Acids?

Amino acids are nitrogen-containing molecules that are the building blocks of all proteins in food and in the body. They can be used as energy, yielding about 4 calories per gram, but their primary purpose is the synthesis and maintenance of body proteins including, but not limited to, muscle mass. Video of the Day During normal protein metabolism, a certain number of amino acids are pushed aside each day. When these amino acids are disproportionate to other amino acids for the synthesis of new protein, your liver and kidneys dispose of the nitrogen as urea, and the rest of the molecule is used as energy in a variety of ways. Then certain amino acids -- minus their nitrogen -- can enter the citric acid cycle -- the biochemical pathway that converts food into energy. Others can be converted to glucose or fat. This process may be enhanced when you take in more protein than you need. Your body relies on a continuous supply of glucose and fatty acids for energy for physical activity and cellular needs during rest. When you exercise, your body relies still more on glucose because fat is slower to metabolize. The higher your exercise intensity is, the more your body requires quicker-burning glucose. Some glucose is stored as glycogen in the liver and muscles and can be recruited when blood glucose is used up. When glycogen becomes depleted, the process of gluconeogenesis can take over -- the creation of new glucose from another source. The usual source for gluconeogenesis is amino acids. Healthy people store adequate body fat to cover their energy needs. Although certain amino acids can be converted to fatty acids, there should be no need for this to occur in order to supply energy. But if a very high protein intake adds substantially more calories, theoretically those extra Continue reading >>

Question: 1. The Body Can Make Long Chain Fatty Acids Through A Process Called &nbs...

Question: 1. The Body Can Make Long Chain Fatty Acids Through A Process Called &nbs...

1. The body can make long chain fatty acids through a process called A. glycolysis B. lipogenesis C . ketogenesis D. lipolysis 2. Once inside a milochondrion, a process called __________ disassembles a fatty acid chain A. ketosis B. cylolysis C. the citric acid cycle D. beta oxidation 3. When a person has diabetes or is starving, ________ help(s) provide emergency energy to all body tissues, especially the brain and central nervous system. A. lipogenesis B. glycolysis C. ketone bodies D. fatty acids 4. The body prefers protein as an energy source True False 5. On average, a person can survive total starvation for 60 days. True False 6. Which type of foods tend to have high satiety value? A. high CHO B. high fat C. high fiber and water content D. low protein 7. Body fat levels of 5-7% for men and 12-19% for women are considered A. high B. just right C. low D. morbidly obese 8. ________________ can trigger your desire for a specific type of food. A . Appetite B. Satiety C. Hunger D. Food intake 9. Having a pear-shaped body is also known as android obesity. True False 10. If a person suffers from hyperplasia, this means A. this person has an above average amount of percentage of fat cells B. his or her fat tissue is likely to have bigger fat cells and more of them C. the person has fat cells which are larger than normal D. the person has lost many fat cells due to excessive weight loss 11. Water provides energy. True False 12. The energy needed to digest, absorb and metabolyze energy-yielding foodstuffs is called____________ A. nonexercise activity thermogenesis B. resting energy expenditure C. thermic affect of food D. negative energy balance 13. Most people overestimate the amount of food they consume. True False 14. The body needs __________ to synthesize fat A. ribofla Continue reading >>

How To Strengthen The Immune System

How To Strengthen The Immune System

Self-Study Examination Instructions: After studying the text answer the following true/false or multiple choice questions. Remember, there's only one answer to each question. 1. Immunity exists in the parasite. a) True b) False 2. The immune system is composed of lymph. a) True b) False 3. The immune system is activated by recognizing any part of the body as non-self. a) True b) False 4. The immune response can be divided into two broad types: humoral response and cell mediated response. a) True b) False 5. Adaptive immunity leads to specific memory which is related to vaccination. a) True b) False a) True b) False 7. Macrophages are the first line of defense in the lymph system. a) True b) False 8. NK cells are the first line of defense against cancer. a) True b) False 9. The T-cell count can fall to zero and a person will still live. a) True b) False a) True b) False 11. Nutrition, age, environment can affect the immune system. a) True b) False a) True b) False 13. When we drink a beer, the body recognizes that a “non-self” chemical has entered and in detoxification calls out its army of B and T cells to fight it. a) True b) False a) True b) False a) True b) False a) True b) False a) True b) False a) True b) False a) True b) False a) True b) False 21. Free radicals neutralize antioxidants. a) True b) False a) True b) False a) True b) False Continue reading >>

Carbohydrates, Proteins, And Fats

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 >>

True Or False

True Or False

(See related pages) 1 Anabolic reactions are those chemical reactions that release energy, usually by the breakdown of larger organic molecules into smaller organic molecules. 2 Aerobic cellular respiration and ventilation describe two very different processes. 3 Within a cell, the oxygen used during aerobic metabolism of nutrients ultimately becomes water. 4 Damage to the mitochondria of a cell would inhibit glycolysis. 7 To summarize glycolysis, one glucose molecule is broken down sequentially to two molecules of pyruvic acid, releasing two NADH + H+ molecules, and generating a net gain of two ATP. 8 It is common for certain tissues like skeletal muscle to derive energy (ATP) from anaerobic respiration on a daily basis without permanent injury or damage to the tissue. 9 Red blood cells only use glycolysis in the catabolism of glucose. 10 Phosphorylation of glucose "traps" the glucose molecule within the cell. 11 In aerobic respiration, pyruvic acid is formed from glucose but lactic acid is not. 12 The enzyme, glycogen phosphorylase, catalyzes the conversion of glycogen to glucose-1-phosphate. 13 Organic molecules with phosphate groups such as glucose 6-phosphate are cell "prisoners" because they cannot cross cell membranes. 14 The liver can supply the skeletal muscle with energy in the form of free glucose but the opposite is not true. 15 Tissue cells that are anaerobic would have to burn relatively more glucose molecules to maintain a steady supply of ATP than would those tissues that are supplied with oxygen. 16 During exercise, the liver can metabolize the lactic acid produced by the skeletal muscle cells and provide glucose to the cells of the body. 17 During aerobic respiration, the reaction that results in the conversion of pyruvic acid to acetyl CoA and CO2, oc Continue reading >>

Nutrition Test 2

Nutrition Test 2

Sort Because they do not consume any animal products, vegans must make extra efforts to include nutrients that are found in animal products but to a much lesser degree, if at all, in plant products. These nutrients are iron, calcium, zinc, and ____________ Vitamin B12 The World Cancer Research Fund and the American Institute for Cancer Research recommend that people limit their intake of red meat to no more than 18 ounces every week and eat very little processed meat. These recommendations are explained by ___________ the 2010 dietary guidelines and myplate During infancy the ability to process the essential fatty acids to other fatty acids such as arachidonic acid and DHA may be impaired due to immature production of the required enzymes. In this situation, arachidonic acid and DHA are considered to be _________________ conditionally essential Continue reading >>

Nutrition 7

Nutrition 7

Home > Preview Of the components listed below,______________is/are not part of the ATP molecule a) adenine b) ribose c) glucose d) three phosphate In glycolysis, glucose is converted to a) pyruvate b) acetyl-CoA c) glycogen d) fat The TCA cycle is initiated by the reaction a) pyruvate + oxaloacetate > acetyl-CoA b) pyruvate + acetyl-CoA > citric acid c) acetyl-CoA + oxaloacetate > citric acid d) acetyl-CoA + citric acid > oxaloacetate The end products of glucose catabolism are a) ATP, ADP, and NAD b) ATP, CO2, and O2 c) NAD, FAD, and H2O d) ATP, CO2, and H2O True/False (support your answer with an explanation) Acetyl-CoA is the "pivotal" point of the TCA cycle because it can either be used to make glucose or to produce energy False Acetyl-CoA is a 2-carbon molecule, which cannot be converted back to pyruvate (a 3-carbon molecule), and so it cannot make glucose. It is the "pivotal" point of the TCA cycle because other substance that are convertible to acetyl-CoA can enter the energy production cycle or be converted to fats for storage at this point Fatty acids are catabolized to produce energy by a) sequential breakdown to form acetyl-CoA, which then enters the TCA cycle b) beta-oxidation to form pyruvate, which then enters the TCA cycle c) hydrolysis to form glycerol, which then enters glycolysis d) beta-oxidation to form oxaloacetate, which then enters the TCA cycle The nitrogen from excess protein in the diet is excreted as a) ammonia b) water c) amino acids d) urea False Ketone bodies are normal metabolites of the body. At low levels of production, the body can metabolize the ketone bodies. In conditions of fasting or in diabetes, ketone production can increase beyond the body's ability to metabolize ketone bodies. The result is ketosis, which, in its mild form can c Continue reading >>

© British Nutrition Foundation 2013

© British Nutrition Foundation 2013

© BRITISH NUTRITION FOUNDATION 2013 Learning objectives To understand that macronutrients are needed by the body to produce energy. To know the functions and sources of carbohydrate, protein and fat. To understand the consequences of not having enough carbohydrate, protein and fat. © BRITISH NUTRITION FOUNDATION 2013 Food is eaten and digested in the body to allow the absorption of energy and nutrients. There are two different types of nutrients: macronutrients; micronutrients. Macronutrients provide energy and these include: carbohydrate; protein; fat. Macronutrients are measured in grams (g). © BRITISH NUTRITION FOUNDATION 2013 Carbohydrate The two types of carbohydrate that provide dietary energy are starch and sugars. Dietary fibre is also a type of carbohydate which is not digested to provide energy. Starchy carbohydrate is an important source of energy. 1 gram of carbohydrate provides 4kcal (17kJ). © BRITISH NUTRITION FOUNDATION 2013 Structure of carbohydrate All types of carbohydrate are compounds of carbon, hydrogen and oxygen. They can be classified in many different ways. One common way is according to their structure. They can be divided into three main groups according to the size of the molecule. © BRITISH NUTRITION FOUNDATION 2013 Monosaccharides These are the simplest carbohydrate molecules. Examples of monosaccharides are: glucose; fructose; galactose. Disaccharides These sugars are formed when two monosaccharide molecules join together with the removal of one molecule of water. Examples of disaccharides are: sucrose (glucose + fructose); lactose (glucose + galactose); maltose (glucose + glucose). Monosaccharides and disaccharides are collectively termed as ‘sugars’. © BRITISH NUTRITION FOUNDATION 2013 Polysaccharides These Continue reading >>

Adipose Tissue

Adipose Tissue

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 >>

Nutrition Ch. 7

Nutrition Ch. 7

Front Back .Wirisformula{ margin:0 !important; padding:0 !important; vertical-align:top !important;} Metabolism The sum total of all the chemcial reactions that go on in living cells. Energy metabolism includes all the reactions by which the body obtains and spends energy from food. Example: Nutrients provide the body with FUEL and follows them through a series of reactions that release energy from their chemical bonds. As the bonds break, they release energy in a controlled version of the process by which wood burns in a fire. Energy metabolism All of the chemical reactions through which the human body acquires and spends energy from food Anabolism Small compounds joined together to make largers ones; energy must be used in order to do this Ana = up Catabolism Larger compounds BROKEN down into smaller ones; energy is RELEASED kata = down Coupled reactions Energy released from the breakdown of a large compounds is used to drive other reactions ATP Adenosine triphosphate; energy currency of the body -- produced when large compounds are broken down ATP is used to make large compounds from smaller ones. Ribosomes Cellular machinery used to make proteins Mitochondria Where energy is derived from fat, CHO, protein via TCA cycle, electron transport chain Coenzyme Complex organic molecules that work with enzymes to facilitate the enzymes' activity. Many coenzymes have B vitamins as part of their structures. co = with Cofactor The general term for substances that facilitate enzyme action is cofactors; they include both organic coenzymes such as vitamins and inorganic substances such as minerals Enzymes Protein catalysts - proteins that facilitate chemical reactions without being changed in the process Metalloenzyme Enzymes that contain one or more minerals as part of their stru Continue reading >>

Biochemistry

Biochemistry

Sort what is the regulation of the citric acid cycle The citric acid cycle is regulated mostly by substrate availability, product inhibition and by some cycle intermediates. • pyruvate dehydrogenase: is inhibited by its products, acetyl-CoA and NADH • citrate synthase: is inhibited by its product, citrate. It is also inhibited by NADH and succinyl-CoA (which signal the abundance of citric acid cycle intermediates). • isocitrate dehydrogenase and a-ketoglutarate dehydrogenase: like citrate synthase, these are inhibited by NADH and succinyl-CoA. Isocitrate dehydrogenase is also inhibited by ATP and stimulated by ADP. All aforementioned dehydrogenases are stimulated by Ca2+. This makes sense in the muscle, since Ca2+ release from the sarcoplasmic reticulum triggers muscle contraction, which requires a lot of energy. This way, the same "second messenger" activates an energy-demanding task and the means to produce that energy. What is the regulation of fatty acid metabolism Acyl-CoA movement into the mitochondrion is a crucial factor in regulation. Malonyl-CoA (which is present in the cytoplasm in high amounts when metabolic fuels are abundant) inhibits carnitine acyltransferase, thereby preventing acyl-CoA from entering the mitochondrion. Furthermore, 3-hydroxyacyl-CoA dehydrogenase is inhibited by NADH and thiolase is inhibited by acetyl-CoA, so that fatty acids wil not be oxidized when there are plenty of energy-yielding substrates in the cell. Explain in overview the metabolic reactions in the body that lead to the formation of ketone bodies (Ketogenesis). Ketogenesis is the process by which ketone bodies are produced as a result of fatty acid breakdown. Ketone bodies are produced mainly in the mitochondria of liver cells, and synthesis can occur in response to una Continue reading >>

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