Chapter 7
Sort What is the difference between energy and metabolism? Energy metabolism? Energy is the capacity to do work - heat, mechanical, electrical, CHEMICAL Metabolism is how the body uses food to meet its needs - specifically, it is the sum total of all chemical reactions in the living cells of the body - energy metabolism includes all reactions by which the body obtains and expends the energy from food What are the two types of metabolic reactions in the body? Anabolic/Anabolism - building body compounds (requires energy) - ex. glucose + glucose = glycogen - ex. glycerol + fatty acid = triglycerides - ex. amino acid + amino acid = protein Catabolic/Catabolism - breaking down body compounds (releases energy) - ex. glycogen -> glucose - ex. triglycerides -> glycerol + fatty acid - ex. protein -> amino acids What is ATP? How is it formed? (adenosine triphosphate) It is a molecule made up of three phosphate groups that has high energy bonds (so it provides lots of energy when it is broken down) - it is what provides energy for any reaction or cell activity in the body It is formed from the breakdown of glucose (glycolysis), fatty acids, and amino acids Its negative charge makes it vulnerable to hydrolysis What is the idea of coupled reactions? The body makes ATP in coupled reactions. Energy (ATP) is needed to facilitate the reactions that make more ATP. So the body uses ATP to make ATP 1.) ATP is broken down, which provides energy for a variety of functions in the body - when ATP is broken down, it loses a phosphate group and becomes ADP 2.) Energy is required to add a phosphate group to ADP to make ATP (uses ATP from food to do this) This system is about 50% efficient, and the rest is lost as heat How does digestion break things down into smaller units? Carbs -> glucose (and Continue reading >>
Chapter 05 Part 2 -- Metabolism Of Lipids
-- glucose is converted into glycogen and fat -- can be used for energy via the same pathways used for the metabolism of pyruvate -- hydrolyzed into glycerol and three fatty acids -- can be converted into acetyl CoA which can then enter the Krebs cycle -- DIAGRAM (3 long chains which are the 3 fatty acids + glycerol) Conversion of Glucose into Glycogen and Fat -- if energy is being delivered to the body faster than it is being consumed (used), excess glucose will enter 2 potential routes for storage: 1) glycogenesis (converting glucose into glycogen molecules) and 2) lipogenesis (converting glucose intermediates into fats) -- When cells have adequate levels of ATP (energy), they down-regulate the respiratory enzymes involved in glycolysis and the Krebs cycle thus the glucose can ONLY enter either glycogenesis or lipogenesis for the purpose of energy storage and NOT complete glycolysis and enter the Krebs cycle and electron transport chain to generate even more ATP (energy). Lipid Metabolism: Lipogenesis (creating fats) -- as ATP levels rise after an energy-rich meal, production of ATP is inhibited: 1. glucose enters glycolysis as normal and the resulting pyruvate is converted into acetyl CoA (acetyl CoA does not enter Krebs cycle though)(the acetyl CoA already formed is joined together to produce a variety of lipids, including cholesterol, ketone bodies, and fatty acids 2. fatty acids combine with glycerol to form triglycerides in the adipose tissue and liver (lipogenesis) -- primarily occurs in two locations: 1. adipose tissue; and 2. liver (fatty liver disease) 1. 80-85% of energy is stored as fat (14,000 kcal) 2. less than 2,000 kcal is stored as glycogen (2/3 of which is stored in skeletal muscle) 3. 15-20% of energy is stored as protein (not extensively used for e Continue reading >>
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Metabolism Flashcards | Quizlet
sum total of all the chemical reactions that take place in living cells all reactions by which the body obtains and uses the energy from food reactions in which smaller molecules are put together to build larger ones (consumes energy) reaction where larger molecules are broken down to smaller ones (release energy) -used as energy currency to build body structures, do work, or generate heat Is the process of changing pyruvate to acetyl CoA reversible? is the process of changing glucose to pyruvate reversible? amino acids that can be used to make glucose are called process of changing glycogenic amino acids to pyruvate reversible? amino acids that can used to make acetyl coA are called process of changing ketogenic amino acids to acetyl coA reversible? process of changing fatty acids to acetyl CoA reversible? the complete oxidation of acetyl CoA is accomplished through the reactions of the TCA cycle and the electron transport chain another 3-carbon compound that can go either "up" or "down" to pyruvate and then to acetyl coA conversion of glycerol to a different 3-carbon compound to make Acetyl CoA irreversible? conversion of lactic acid to pyruvate irreversible? what makes triglycerides an insignificant source of glucose typical triglycerides contain only one small molecule of glycerol, but has 3 fatty acids. Only the glycerol portion of a triyglyceride can yield glucose production of acetyl CoA from pyruvate requires___and __ excreted as waste pairs of chemical reactions in which some of the energy released from the breakdown of one compound is used to create a bond in the formation of another compound proteins that facilitate chemical reactions without being changed in the process complex organic molecules that work with enzymes to facilitate the enzymes activity. a 2 Continue reading >>
Nutrition Ch. 7 Energy Metabolism
- all the ways the body obtains and uses energy from food - releases carbon dioxide, water and produces energy Where does all of the energy that sustains human life come from? - process by which green plants use the sun's energy to make carbohydrates from carbon dioxide and water - compounds that cells can use for energy - glucose, fatty acids, amino acids, ketone bodies, lactate, glycerol, and alcohol - liver cells are most versatile and metabolically active - reaction in which small molecules are put together to build larger ones (building body compounds) - includes making of glycogen, triglycerides, and protein - reaction in which large molecules are broken down into smaller ones - releases energy (captured in bonds of ATP) - breakdown of glycogen, triglycerides, and protein - high energy compound composed of purine (adenine), a sugar (ribose), and 3 phosphate groups (the negative charged make ATP vulnerable to hydrolysis) - pairs of chemical reactions in which some of the energy released from the breakdown of one compound is used to create a bond in the formation of another compound - ex: hydrolysis of ATP, body uses ATP to transfer the energy released during catabolic reactions to power anabolic reactions that require energy - enzymes: facilitators of metabolic reactions - coenzymes: organic, associate with enzymes but aren't proteins, w/o a coenzyme an enzyme can't function all of these results have C, N, O, and H; bonds break and release energy - amino acids and glycerol can be converted to pyruvate - fatty acids can be converted to acetyl CoA - 6 carbon glucose is converted to 6 carbon compound before splitting in half to form two 3 carbon compounds - the 3 carbon compounds continue on the pathway until they're converted to pyruvate - the net yield of one gluco Continue reading >>
Fatty Acid Metabolism
Oxidation of hydroxyl group to form carbonyl group using NAD+ as the oxidizing agent Enzyme: L--Hydroxyacyl-CoA dehydrogenase Thiolysis reaction in which acetyl CoA is released followed by attachment of another coenzyme A to give fatty acyl-CoA Thioester bond formation between fatty acid and coenzyme A to produce fatty acyl-CoA Requires ATP (ATP to AMP) -Oxidation of fatty acyl-CoA using the oxidizing agent FAD to create a double bond, Enol CoA * Ketoacyl CoA + CoA SH = Fatty-acyl-CoA + Acetyl-CoA* -Thiolysis reaction in which acetyl CoA is released followed by attachment of another coenzyme A to give fatty acyl-CoA TGs are hydrolyzed to release fatty acids. Where do fatty acids that are released by TG's go? Transported into the matrix of mitochondria where they are oxidized to make ATP Where are fatty acids oxidized to make ATP? Excess production of acetyl CoA occurs when carbohydrate intake is low (starvation, low carbohydrate diets) or in case of diabetes (glucose can't enter cells to be utilized) Under starvation circumstances, acetyl CoA that is produced during fatty acid -oxidation is converted into ketone bodies (acetoacetate, acetone, -hydroxybutarate) These ketone bodies are delivered from the liver to other tissues and then converted back into acetyl CoA to be used in the citric acid cycle Fuses two acetyl CoA molecules to produce acetoacetyl CoA What is the carrier group in Fatty Acid Synthase: What is happening in Fatty Acid synthesis: Synthesis of Fatty Acids to be stored as Triglycerides. -Excess acetyl CoA produced by carbohydrate degradation is used to make fatty acids that are then stored as triglycerides. What is the multi enzyme complex of Fatty Acid synthesis? NADP+/NADPH rather than NAD+/NADH and FAD+/FADH2 Why is a different electron carrier used: Continue reading >>
Nutrition Chapter 7 (test 2)
Sort acetyl CoA -two carbon compound that pyruvate is converted to in an aerobic environment -occurs in mitochondria -releases carbon dioxide -cannot be reversed through glucose synthesis (unlike conversion of lactate to glucose) -can be further metabolized to produce ATP or redirected into fatty acid synthesis -links glycolysis to the TCA cycle -marks transition from cytosol baed pathways to mitochondria based pathways TCA cycle -continuous cycle of 8 metabolic reactions -located in the mitochondria -needs oxaloacetate to function -acetyl CoA reacts with oxaloacetate to form citrate -produces 2 carbon dioxides, GTP (equivalent to one ATP), eight hydrogen which are transferred to coenzymes NAD and FAD to produce NADH and FADH2), which transport the hydrogen and their electrons to the electron transport chain -must complete two rotations for each molecule of glucose b-oxidation also known as fatty acid oxidation takes place in mitochondria fatty acids activated by Coenzyme A so they can be moved across mitochondrial membrane once in the mitochondria, breaking down the fatty acid in two carbon segments to make one acetyl CoA unit high energy electrons transferred to coenzymes NAD and FAD acetyl coA feeds into TCA cycle and onto the electron transport chain produces more ATP than glucose catabolism and have fewer oxygen atoms, resulting in higher output of NADH and FADH2 fatty acids have a much higher potential energy than glucose it is IMPOSSIBLE for fatty acids to be converted to glucose proteolysis protein breakdown, dietary proteins are digested into single amino acids or small peptides that are absorbed in the body amino acids are transported to the liver, where they can be made into different proteins or released into the bloodstream for uptake by other cells no amin Continue reading >>
Nutrition-chapter 7
Sort Carbohydrates -Metabolizes fructose, galactose, and glucose - Makes and stores glycogen -Breaks down glycogen and releases glucose -Breaks down glucose for energy when needed -Makes glucose from some amino acids and glycerol when needed -Converts excess glucose and fructose to fatty acids - Lipids lipids -Builds and breaks down triglycerides, phospholipids, and cholesterol as needed -Breaks down fatty acids for energy when needed - Packages lipids in lipoproteins for transport to other body tissues -Manufactures bile to send to the gallbladder for use in fat digestion -Makes ketone bodies when necessary Proteins -Manufactures nonessential amino acids that are in short supply -Removes from circulation amino acids that are present in excess of need and converts them to other amino acids or deaminates them and converts them to glucose or fatty acids -Removes ammonia from the blood and converts it to urea to be sent to the kidneys for excretion - Makes other nitrogen-containing compounds the body needs (such as bases used in DNA and RNA) -Makes many proteins other -Detoxifies alcohol, other drugs, and poisons; prepares waste products for excretion -Helps dismantle old red blood cells and captures the iron for recycling -Stores most vitamins and many minerals -Activates vitamin D Continue reading >>
Nutrition Ch. 6 Flashcards | Quizlet
Condensation reactions build molecules; this is known as ____, and it requires ____. _____ reactions involve hydrolysis, and they release energy in the form of ____. The phosphate groups are hydrolized and broken off. When catabolic and anabolic reactions occur simultaneously About ____ of the chemical energy from food is turned into chemical energy in the form of ATP. The rest is lost as ____. Metabolic reactions almost always require ____, and these in turn require _____. coenzymes, enzymes in energy metabolism reactions When excess kcalories are available, metabolism favors _____, no matter what the source. On average, converting dietary fat to body fat requires only ____ of the ingested energy intake, while converting carbohydrates to body fat requires ____ of the ingested energy intake. The body cannot store excess _____. They must be converted to other compounds. First, it is used for normal replacement/repair. Then protein oxidation (metabolism by cells) increases at the expense of fat metabolism. Last, they are converted to fatty acids. How is excess carbohydrate used by the body? Glucose oxidation increases, displacing fat. Excess is stored as glycogen. Some is stored as fat, but this is a minor pathway. More importantly, glucose oxidation responds readily to to excess carbohydrate (cells use a higher proportion of carbs than normal), sparing dietary and body fat. Thus excess carbohydrates contribute to weight maintenance. Excess protein and carbohydrate increase _____ of these substances by cells. They become a greater part of the body's fuel mix at the expense of ____. T/F: Excess consumption of fat increases fat oxidation by cells. False - since unlimited fat can be stored, there is no need for the body to increase fat oxidation How does the body supply its Continue reading >>
Nutrition Chapter 7
Sort Feasting eating in excess of energy needs metabolism favors fat formation - dietary fat to body fat is most direct and efficient conversion (carbohydrate and protein have other roles to fulfill before) fuel mix - depends on diet; carbohydrate and protein intakes influence fuel mix; increases in carbohydrate and protein intakes DISPLACE fat in the diet (more carbohydrate/protein and less fat) increase fat eaten DOES NOT enhance fat breakdown - does not respond to dietary fat intake! Transition from Feasting to Fasting after a meal (2-3 hours), glucose, glycerol, fatty acids used as needed, stored - fasting state draws on these stores (glycogen and fat are released/broken down) energy needed all the time! (sleeping) basal metabolism - cell's work to maintain life processes; 2/3 energy a person expends per day fasting (choice) vs. starving (no choice) - body cannot distinguish difference between them, forced to draw on reserves of carbohydrate and fat Fasting carbohydrate, fat, protein all eventually used as energy begins with release of glucose from liver's glycogen stores, fatty acids from adipose cells breakdown and acetyl CoA produced - Krebs cycle to produce energy (ATP) decrease blood glucose levels serve as signal - promotes further fat breakdown; release of amino acids from muscles Fatty Acids as Fuel good for now, but glucose is needed brain, nervous system, and RBC - primary source brain/nerve cells consume 1/2 total glucose used/day (50%) 1/4 of energy body uses at rest spent by brain RBC completely dependent on glucose, brain/nerve cells prefer glucose for energy Protein to the Rescue amino acids yielding pyruvate (to make glucose); breakdown of body proteins; amino acids that canoot make glucose used for energy by other cells; expensive way to make glucos Continue reading >>
Biochemistry 1 - Week 1
..., are responsible for the chemical changes that break foods down into simpler forms of nutrients for use by the body, proteins found in digestive juices that act on food substances, causing them to break down into simpler compounds, trypsinogen, trypsin, protease, lipases, amylases, nucleases, proteases, Lipase, amylase, chymotrypsin, tryspin, and carboxypeptidase., the chief cells of the gastric glands secrete, break bonds between atoms in large molecules to produce smaller molecules. Produced by salivary glands, cells lining the stomach and small intestine, and the pancreas., embedded in the intestinal epithelial cells and break food down just before absorption/peptidase, sucrase, maltase, lactase and lipase, proteins that aid in the breakdown of food: pepsin and salivary amylase, Protein molecules that speed up digestion by catalyzing chemical reactions. Digestive enzymes catalyze chemical reactions known as hydrolysis reactions., catalyst that facilitate a chemical reaction without being changed or used up in the process; usually end in ase(protein), cleave -glycosidic likages in starch, not -glycosidic bonds in cellulose (insoluble fiber) What are the physiologic and anatomic steps to digestion? Ingestion, Absorption, Transport, Metabolize d. The Cytochrome System and Oxidative Phosphorylation., glucose<---->glycogen lactic acid ----> glucose, ketones, zinc deficiency = decreased insulin and the response = impaired glucose tolerance, Oxidation of glucose (cellular respiration): Glycolysis, Kreb's cycle, and Electron transport chain., hepatocytes break down glycogen reserves and release glucose into the bloodstream., fate of glucose depends on needs of body. ATP production or synthesis of amino acids, glycogen, or triglycerides. GluT transporters bring glucose i Continue reading >>
Ntdt Chapter 7 Flashcards | Quizlet
mechanical, chemical, electrical and heat energy, water and carbon dioxide are released how the body obtains and uses energy from foods type and extent of metabolic activities depends on what what organ's cells are the most metabollically active what functions do the liver cells carry out? gluconeogenesis, hormone production, enzyme production endoplasmic reticulum w/ ribosomes -site of protein synthesis what is the lattice type structure that supports and controls the movement of the cells structures, filled with cytosol fills the lattice strcuture of the cytoplasm, houses the enzymes involved in glycolysis what provides energy for all cells of the body breakdown of glucose, fatty acids and amino acids can pyruvate be conceverted back to glucose? 1 glucose equals how many pyruvate and acetyl COA which of the macronutrients can be broken down into acetyl coa? what part of a protein turns into acetyl coa glucose turns into what before it turns into acetyl coa gylcerol from fat and glucogenic amino acids turns into what what molecule enters the krebs/tca cycle? when breaking down carbs, lipids and proteins, what element is released? what happens to it? H+, they are taken by coenzymes to the electron transport chain to make ATP or water in what cells can pyruvate be converted back to glucose? what is the couple reaction that occurs using ATP? hydrolysis of ATP occurs ate the same that that reactions with use energy to build compounds what is ATP used for regarding catabolic and anabolic reactions? ATP is used to transfer the energy released during catabolic reaction to power anabolic reactions what is the efficiency of the body converting energy to ATP? what is released when a phosphate bond in ATP is broken? When a phosphate group is lost from ATP, what does it become? w Continue reading >>
Metabolism
Sort Catabolism Degradation from large complex molecules to smaller simple ones: 1) Carbohydrate Catabolism: a) Glycolysis b) Penthose Phosphate Passway c) Kerbs Cycle (Cytric Acid Cycle) d) Electron transport Chain e) Glycogenolysis 2) Lipid Catabolism a) β oxidation b) Ketone metabolism c) Cholestrol catabolism 3) Protein Catabolism 4) Nucleic Acid Catabolism Glycolysis: Definition and Enzymes Converts Glucose to Pyruvate (or Lactate in anaerobic conditions) Net energy yield: 2 ATP, 2 NADH Steps: 1) Glucose ---> Glucose-6p 2) Glucose-6p <---> Fructose-6p 3) Fructose-6p ---> Fruktose-1,6 bisphosphate --- 4) Fruktose-1,6 bisphosphate <--->Glyceraldehyde-3p + DHAP 4-a) Glyceraldehyde-3p <---> DHAP 5) Glyceraldehyde-3p <---> 1,3-Biphosphoglycerate 6) 1,3-Biphosphoglycerate <---> 3-Phosphoglycerate 7) 3-Phosphoglycerate <---> 2-Phosphoglycerate 8) 2-Phosphoglycerate ----> Phosphoenylpyruvate (PEP) 9) PEP ---> Pyruvate Enzymes: 1) Hexokonase (Glucokinase in liver), 2) Glucose 6-p isomerase (Phosphoglucose isomerase) 3) PFK, 4) Aldolase, 4-a) Triose-phosphate isomerase, 5) Glyceraldehyde-phosphate dehydrogenase, 6) Phosphoglycerate kinase, 7) Phosphoglycerate mutase, 8) Enolase, 9) Pyruvate Kinase Hexokinase, PFK and Pyruvate Kinase are irreversible and regulatory PFK is Rate Limiting Step ATP is used in steps 1 & 3 NADH produced in 5 ATP produced in 6 & 9 Glycolysis: regulators 1) Hexokinase inhibited by:G6P (In Liver: Glucokinase regulated by: Glucokinase regulatory protein: GKRP) 2) PFK-1 Stimulated by AMP & Fructose-2,6-bisphosphate⁰ and inhibited by ATP & Citrate PFK-2 stimulated by Insukine and inhibited by Glucagon 3) Pyruvate kinase activated by: fructose-1,6-bisphosphate and Insuline⁰, Inhibited by ATP, Acetyl-CoA, Glucagon⁰ and Alanine⁰ ⁰Liver specific G Continue reading >>
Nutrition Chapter 7 Flashcards | Quizlet
Glucose, fatty acids, amino acids, ketone bodies, lactate, glycerol, alcohol Reactions in which small molecules are put together to form large ones. Requires energy. Reactions in which large molecules are broken apart, with the release energy. Latice-like structure that supports the cell's structures. Filled with cytosol, which contains enzymes involved with glycolysis Dotted with ribosomes, the site of protein synthesis Site of oxidative reactions of metabolism Houses all the enzymes involved in the conversion of pyruvate to acetyl CoA, fatty acid oxidation, the TCA cycle, and the electron transport chain. Metabolic work of the liver: Carbohydrates Converts fructose and galactose to glucose Breaks down glycogen to release glucose Builds and breaks down triglycerides, phospholipids, and cholesterol Breaks down fatty acids to provide energy Packages excess lipids in lipoproteins for transport Manufactures nonessential amino acids that are in short supply Removes from circulation amino acids that are present in excess of needs Removes ammonia from the blood and converts it to urea Makes nitrogen-containing compounds such as bases of DNA and RNA Dismantles and recycles old blood cells High-energy storage compound with three high-energy phosphate bonds Composed of a purine (adenine), a sugar (ribose), and 3 phosphate groups These bonds have negative charges that make them vulnerable to hydrolysis Hydrolysis of ATP, which releases energy, happens simultaneously with reactions that use that energy. Efficiency of conversion of chemical energy of food to chemical energy of ATP A complex organic molecule that associates closely with an enzyme, but is not a protein itself. Help carry H (with high energy electrons) from nutrient breakdown to ETC. A 3-carbon compound that plays a Continue reading >>
Nutrition Ch. 7
• ATP (transfer of energy in reactions) o one of the main energy-storage molecules: only form of energy that can be used directly by cells to do work they need to do o Made up of 3 phosphate groups o add water - Hydrolysis of its phosphate groups generates energy • Provides energy that powers living cell activity • Body captures and releases energy in bonds of ATP o Involved in coupled reactions • coupled reactions: hydrolysis at time body needs energy • Body converts chemical energy of food to chemical energy of ATP -when used, called ADP • Pyruvate #1 → lactate - When body needs energy quickly, but energy doesn't last long (couple of minutes) - Anaerobic (no oxygen) - Pyruvate accepts hydrogen - Occurs even a little at rest - During intense exercise, lactate accumulates in muscles and causes blood pH drop, burning pain, and fatigue - Liver can convert lactate to glucose - called Cori cycle (recycling process) o Pyruvate → acetyl CoA • When body expends energy more slowly, but energy sustained for longer (greater total energy yield) • Aerobic (requires oxygen) • Carbon group removed from 3-carbon pyruvate → 2-carbon compound → bonds with CoA → acetyl CoA • Produces carbon dioxide • Not reversible pathway • Much more ATP produced than glycolysis • Amino acids o Amino acid deamination occurs (lose their nitrogen-containing amino group) o Amino acid pathways: • Some amino acid → pyruvate -- Can provide glucose • Some amino acid → acetyl CoA -- Can provide additional energy or make body fat (but not glucose) • Some amino acid enter TCA cycle directly as compounds -- Can generate energy in cycle -- Can generate glucose Continue reading >>
Ch 25 Flashcards | Quizlet
a. is the conversion of one molecule of glucose into two molecules of pyruvic acid. b. is the conversion of two molecules of glucose into one molecule of pyruvic acid. c. concludes with formation of acetyl coenzyme A. d. generates a usable total of 4 ATP molecules. e. requires oxygen for efficient conversion of glucose into pyruvic acid. a. is the conversion of one molecule of glucose into two molecules of pyruvic acid. a. is formed through oxidation of pyruvic acid. b. formation requires pyruvate dehydrogenase. ATP is produced through chemiosmosis in the cytosol of the cell, and may occur under aerobic or anaerobic conditions. Which of the following places the events of glucose catabolism in the correct order? a. glycolysis, formation of acetyl coA, Krebs cycle, electron transport chain reactions b. glycolysis, Krebs cycle, formation of acetyl coA, electron transport chain reactions c. glycolysis, anaerobic respiration, Krebs cycle, electron transport chain reactions d. glycolysis, Krebs cycle, anaerobic respiration, electron transport chain reactions e. formation of acetyl coA, glycolysis, electron transport chain reactions a. glycolysis, formation of acetyl coA, Krebs cycle, electron transport chain reactions Glycolysis requires only phosphorylation and does not involve dephosphorylation. If adequate O2 is present in the mitochondria, pyruvic acid will be converted to ______; if conditions are anaerobic, pyruvic acid will be converted to ______. The first molecule formed in the Krebs cycle is Which of the following statements about the process of deamination is FALSE? b. required for oxidation of amino acids in the Krebs cycle d. all of these choices are possible fates of an amino acid. e. none of these choices is possible fates of an amino acid. d. all of these cho Continue reading >>
