SEHS Topic 3 Nutrition PDF

3.1 - Nutrition Assessment Statement Notes 3.1.1 List the macronutrients and micronutrients Macro–lipid (fat), carbohydrate, water, and protein. Micro–vitamins, minerals, and fiber. 3.1.2 Outline the functions of macronutrients and micronutrients Specific knowledge of individual vitamins and...

3.1 - Nutrition Assessment Statement Notes 3.1.1 List the macronutrients and micronutrients Macro–lipid (fat), carbohydrate, water, and protein. Micro–vitamins, minerals, and fiber. 3.1.2 Outline the functions of macronutrients and micronutrients Specific knowledge of individual vitamins and minerals is not required. 3.1.3 State the chemical composition of a glucose molecule C, H, and O (1:2:1 ratio) 3.1.4 Identify a diagram representing the basic structure of a glucose molecule 3.1.5 Explain how glucose molecules can combine to form disaccharides and polysaccharides Condensation reaction—the linking of a monosaccharide to another monosaccharide, disaccharide or polysaccharide by the removal of a water molecule. 3.1.6 State the composition of a molecule of triacylglycerol Limit to glycerol and three fatty acids. 3.1.7 Distinguish between saturated and unsaturated fatty acids Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain. Saturated fats originate from animal sources, for example, meat, poultry, full-fat dairy products and tropical oils, such as palm and coconut oils. Unsaturated fatty acids contain one or more double bonds between carbon atoms within the fatty acid chain. Unsaturated fats originate from plant-based foods, for example, olive oil, olives, avocado, peanuts, cashew nuts, canola oil and seeds, sunflower oil and rapeseed. 3.1.8 State the chemical composition of a protein molecule Limit to C, H, O and N. 3.1.9 Distinguish between an essential and a non-essential amino acid Essential amino acids cannot be synthesized by the human body and must be obtained from diet. Non-essential amino acids can be synthesized by the human body. 3.1.10 Describe current recommendations for a healthy balanced diet Consider recommendations for carbohydrates, proteins, lipids, fiber, water and salt for adults in the general population. The relative contribution of carbohydrate, protein, and lipid (including monounsaturated, polyunsaturated and saturated) should be given. Aim 9: Recommended intakes of nutrients have been published in some countries. The recommendations vary and this raises questions about how the levels are decided. Int/Aim 8: Students can be made aware of the sociocultural influences of food selection and preparation across populations, for example, Mediterranean, Japanese, Western (USA, UK) and Indian. 3.1.11 State the approximate energy content per 100g of carbohydrate, lipid, and protein Students should know that the energy content values per 100 g are: carbohydrate 1760 kJ, lipid 4000 kJ, and protein 1720 kJ. 3.1.12 Discuss how the recommended energy distribution of the dietary macronutrients differs between endurance athletes and non-athletes Limit to the important difference in carbohydrate intake and how therefore this also affects fat and protein intake. For example, carbohydrate intake is higher, protein and fat intake is slightly higher for a marathon runner than a non-athlete, and vice versa. Int: Variation between countries, for example, a high-carbohydrate diet consumed by athletes in some countries. Aim 8: Some sports require smaller stature therefore diet manipulation may occur prior to competition. Aim 9: Recommended intakes vary within published literature. 3.1.1 - List the macronutrients and micronutrients Macronutrient: lipids (fat), carbohydrates, water and protein Micronutrient: vitamins, minerals and fiber 3.1.2 - Outline the functions of macronutrients and micronutrients Macronutrient - nutrients that provide the energy necessary to maintain bodily functions during rest and physical activity (needed in large amounts) Micronutrients - facilitate energy transfer and tissue synthesis (needed in small amounts) Carbohydrates - provide fuel for the body and act as energy storage Protein - repair and growth of muscle tissue Lipids - protects vital organs and helps with thermoregulation Water - transportation and thermoregulation Fiber - helps the digestive system Vitamins - energy release from macronutrients Minerals - elements found in food that are used by the body 3.1.3 - State the chemical composition of a glucose molecule CH2O ratio of 1:2:1 ⟶ C6H12O6 1 Carbon : 2 Hydrogens : 1 Oxygen 3.1.4 - Identify a diagram representing the basic structure of a glucose molecule 3.1.5 - Explain how glucose molecules can combine to form disaccharides & polysaccharides mono di poly one two many Condensation Reaction - the combination of two or more than two monosaccharides to create a disaccharide or a polysaccharide where a water molecule is removed in the process Monosaccharides can undergo a series of condensation reactions, adding one unit after another to the chain until a polysaccharide is formed. When two monosaccharides react a water molecule is lost and a disaccharide is created through condensation reaction. - When one glucose molecule combines with another glucose molecule it creates maltose which is a disaccharide - When a lot of glucose molecules combine together, they create a polysaccharide, for example, glycogen 3.1.6 - State the composition of a molecule of triacylglycerol 1 Glycerol : 3 Fatty Acids 3.1.7 - Distinguish between saturated and unsaturated fatty acids Saturated Unsaturated - have no double bonds between their carbon atoms - solid at room temperature - from animal sources ex. butter - have one or more bond between their carbon atoms - liquid at room temperature - from plant-based foods ex. oil 3.1.8 - State the chemical composition of a protein molecule CHON ratio of 1:1:1:1 1 Carbon : 1 Hydrogen : 1 Oxygen : 1 Nitrogen 3.1.9 - Distinguish between an essential and a non-essential amino acid Essential Amino Acids - can only get them from food Non-essential Amino Acids - can get from food and can be made by the body 3.1.10 - Describe current recommendations for a healthy balanced diet - intake 45–65 % carbohydrate, 10−35 % fat, 20−35 % protein - reduce daily sodium intake - keep trans fatty acid consumption as low as possible - reduce the intake of calories from solid fats and added sugars - choose a variety of protein foods (seafood and beans) - adequate water consumption 3.1.11 - State the approximate energy content per 100g of carbohydrate, lipid, and protein Carbohydrate Lipid Protein 1760 kJ 4000 kJ 1720 kJ 3.1.12 - Discuss how the recommended energy distribution of the dietary macronutrients differs between endurance athletes and non-athletes - Carbohydrate, protein and water intake is higher for athletes than for non athletes - Fat intake is slightly higher for athletes than for non athletes 3.2 - Carbohydrate and Fat Metabolism Assessment Statement Notes 3.2.1 Outline metabolism, anabolism, aerobic catabolism and anaerobic catabolism Metabolism: All the biochemical reactions that occur within an organism, including anabolic and catabolic reactions. Anabolism: Energy requiring reactions whereby small molecules are built up into larger ones. Catabolism: Chemical reactions that break down complex organic compounds into simpler ones, with the net release of energy. 3.2.2 State what glycogen is and its major storage sites 3.2.3 State the major sites of triglyceride storage Adipose tissue and skeletal muscle 3.2.4 Explain the role of insulin in the formation of glycogen and the accumulation of body fat 3.2.5 Outline glycogenolysis and lipolysis 3.2.6 Outline the functions of glucagon and adrenaline during fasting and exercise 3.2.7 Explain the role of insulin and muscle contraction on glucose uptake during exercise Emphasize that both insulin and muscle contraction stimulate glucose uptake from the blood into skeletal muscle 3.2.1 - Outline metabolism, anabolism, aerobic catabolism and anaerobic catabolism Metabolism - all the biochemical reactions that occur within an organism, including anabolic and catabolic reactions Anabolism - energy requiring reactions whereby small molecules are built up into larger ones Aerobic catabolism - chemical reactions that break down complex organic compounds into simpler ones, with the net release of energy Anaerobic catabolism - the breakdown of complex chemical substances into simpler compounds, with the release of energy, in the absence of oxygen 3.2.2 - State what glycogen is and its major stores Glycogen - stored glucose, it is a polysaccharide made out of glucose - Stored in the liver and muscles 3.2.3 - State the major sites of triglyceride storage Stored in adipose tissue (fat) and in skeletal muscle 3.2.4 - Explain the role of insulin in the formation of glycogen and the accumulation of body fat ⟶ insulin is secreted from the beta cells in the pancreas in response to high levels of sugar in the blood ⟶ it transforms glucose to glycogen and stores it in the liver and in muscles ⟶ it transforms glycerol and fatty acids to lipids, and amino acids into proteins, it stores this in the body ⟶ insulin stops glycogenolysis, lipolysis and the breakdown of proteins into amino acids ⟶ things build up and get stored (anabolism) instead of breaking down ⟶ insulin helps to maintain a normal level of sugar in the blood 3.2.5 - Outline glycogenolysis and lipolysis Glycogenolysis - the breakdown of glycogen back into glucose so it can be released into the blood Lipolysis - the breakdown of stored lipids into glycerol and fatty acids 3.2.6 - Outline the functions of glucagon and adrenaline during fasting and exercise Glucagon is released from the alpha cells in the pancreas in response to low blood glucose Adrenaline is released from the adrenal glands when the body is in a stressful situation During fasting: - Levels of glucagon and adrenaline increase ⟶ Glucagon causes glycogenolysis to happen (glycogen into glucose) ⟶ Adrenaline will stimulate glycogenolysis, causing an increase in blood sugar levels - Both of these hormones are lipolysis inducers, they mobilize fat stores from the adipose tissues for breakdown into useful energy 3.2.7 - Explain the role of insulin and muscle contraction on glucose uptake during exercise During exercise, the greater amount of muscle contraction requires increased amounts of glucose to provide the energy required for contraction Glycogen is stored in the muscles, and it is the main source of fuel during strenuous, short-term exercise Blood-borne-glucose and free fatty acids that come from adipose tissue are usually used during prolonged exercise Insulin stimulates glucose uptake from the blood into skeletal muscle During exercise, insulin levels fall, and glucagon and adrenaline levels rise, so overall: - Less glucose is absorbed by the liver - More glycogenolysis occurs causing the release of more glucose into the blood Therefore, blood glucose is absorbed by muscles during exercise 3.3 - Nutrition and Energy Systems Assessment Statement Notes 3.3.1 Annotate a diagram of the ultrastructure of a generalized animal cell The diagram should show ribosomes, rough endoplasmic reticulum, lysosomes, Golgi apparatus, mitochondria and nucleus. 3.3.2 Annotate a diagram of the ultrastructure of a mitochondrion Cristae, inner matrix and outer smooth membrane 3.3.3 Define the term cell respiration Cell respiration is the controlled release of energy in the form of ATP from organic compounds in cells 3.3.4 Explain how adenosine can gain and lose a phosphate molecule 3.3.5 Explain the role of ATP in muscle contraction Limit to the breakdown of ATP to ADP releasing a phosphate molecule, which provides energy for muscle contraction. Cross reference with 4.1.3. 3.3.6 Describe the re-synthesis of ATP by the ATP-PC system Creatine phosphate (a high energy molecule) is broken down to provide a phosphate molecule for the re-synthesis of ATP that has been utilized during the initial stage of exercise 3.3.7 Describe the production of ATP by the lactic acid system Also known as anaerobic glycolysis—the breakdown of glucose to pyruvate without the use of oxygen. Pyruvate is then converted into lactic acid, which limits the amount of ATP produced (2 ATP molecules). 3.3.8 Explain the phenomena of oxygen deficit and oxygen debt Oxygen debt is now known as excess post-exercise oxygen consumption (EPOC). 3.3.9 Describe the production of ATP from glucose and fatty acids by the aerobic system Limit to: in the presence of oxygen pyruvate is processed by the Krebs cycle which liberates electrons that are passed through the electron transport chain producing energy (ATP). Fats are also broken down by beta oxidation that liberates a greater number of electrons thus more ATP. In the presence of oxygen and in extreme cases protein is also utilized. 3.3.10 Discuss the characteristics of the three energy systems and their relative contributions during exercise Limit to fuel sources, duration, intensity, amount of ATP production and by-products. 3.3.11 Evaluate the relative contributions of the three energy systems during different types of exercise Energy continuum. Different types of exercise (endurance athlete, games player, sprinter) should be considered. 3.3.1 - Annotate a diagram of the ultrastructure of a generalized animal cell 3.3.2 - Annotate a diagram of the ultrastructure of a mitochondrion 3.3.3 - Define the term cell respiration Cell Respiration - the controlled release of energy in the form of ATP from organic compounds in cells 3.3.4 - Explain how adenosine can gain and lose a phosphate molecule - When energy is released from ATP, a phosphate molecule is lost - From ATP (Adenosine Triphosphate) to ADP (Adenosine Diphosphate) - When ATP is resynthesized using the energy given off from Creatine Phosphate, a phosphate molecule is gained. - From ADP (Adenosine Diphosphate) to ATP (Adenosine Triphosphate) 3.3.5 - Explain the role of ATP in muscle contraction From ATP (Adenosine Triphosphate), broken by ATPase: To ADP (Adenosine Diphosphate) + P (Phosphate) + Energy: - ATP is broken down into ADP, during this process, the bond between the phosphate molecules releases energy. - This energy is used for muscle contraction - As ATP stores are low in our bodies, it has to be re-synthesized to allow us to keep exercising There are the 3 energy systems that help with the re-synthesis of ATP: 1. Phosphocreatine System (ATP-PC) 2. Lactic Acid System (Anaerobic Glycolysis) 3. Aerobic System 3.3.6 - Describe the re-synthesis of ATP by the ATP-PC system Phosphocreatine System (ATP-PC) - Anaerobic Reaction - Occurs in the cytoplasm of the muscle cells - Produces 1 ATP - ATP is resynthesized very quickly Steps: 1. Creatine phosphate has a high energy bond that’s broken by creatine kinase 2. This energy is used to resynthesize 1 molecule of ATP 3. The phosphate that is separated from the creatine phosphate and the energy that is created, goes into the ADP to create ATP 4. Therefore, ADP gains 1 phosphate molecule by using the energy, creating ATP 5. ATP is then broken down with the help of ATPase, and the energy from the broken bond is released and used for exercise Advantages Disadvantages - it can produce energy quickly since no oxygen is required - only lasts a 1-2 seconds Example Sport: 50m Sprint 3.3.7 - Describe the production of ATP by the lactic acid system Lactic Acid System (Anaerobic Glycolysis) - Anaerobic Reaction - Occurs in the cytoplasm of the muscle cells - Produces 2 ATPs - ATP is resynthesized quickly Steps: 1. Glucose is broken down by glycolysis into pyruvate, giving off energy (2 ATPs) 2. Since oxygen is not present, the pyruvic acid is converted to lactic acid 3. Lactic acid is the by-product, and it leads to an increase in hydrogen ions - lactic acid accumulates in our cells and the acidity causes fatigue 4. In order to get rid of the lactic acid, you must breathe aerobically, to pay back the oxygen debt 5. The oxygen will remove the lactic acid and change it back to pyruvate Advantages Disadvantages - it can produce energy quickly since no oxygen is required - cells become more acidic leading to fatigue - it can only provide energy for 30 sec - 2 min Example Sport: 400m Sprint 3.3.8 - Explain the phenomena of oxygen deficit and oxygen debt Oxygen Deficit - the amount of oxygen required during exercise Oxygen Debt- the amount of oxygen that needs to be repaid after vigorous exercise aka EPOC (Excess Post-Exercise Oxygen Consumption) Components of Oxygen Recovery Alactic Acid (fast/rapid component): Resynthesize muscle stores of ATP-PC - Takes 3-4 min for stores to fully recover - Uses 3-4 liters of oxygen Replenishment of myoglobin stores with oxygen Lactic Acid (slow component): Removal of lactic acid from muscles and blood Maintenance of body temperature and ventilation - Can take up to 48h - Uses 5-8 liters of oxygen 3.3.9 - Describe the production of ATP from glucose and fatty acids by the aerobic system Aerobic System - Aerobic Reaction - Occurs in the matrix and in the cristae of the mitochondria - Produces 36-38 ATPs - ATP is resynthesized slowly Steps: 1. Glucose is broken down by glycolysis into pyruvate 2. Since oxygen is present, the pyruvate produced is converted to Acetyl CoA 3. It enters the aerobic system (Krebs Cycle and Electron Transport Chain) Krebs Cycle: - Happens in the matrix of the mitochondria - This process produces around 2 ATPs This is where Acetyl CoA is converted into: a. Water b. Carbon dioxide c. Hydrogen (used in the ETC) Electron Transport Chain (ETC): - Happens in the cristae of the mitochondria - This process produces around 32-34 ATPs The hydrogen produced in the Krebs Cycle is: - Split into hydrogen ions and electrons, these are charged with energy - The hydrogen ions combine with oxygen to create water - The electrons provide the energy to resynthesize the ATP - In total, the aerobic system creates 36-38 ATPs (2 from Krebs and 32-34 from ETC) The aerobic energy system can not only break down glucose, but it can also break down fats and proteins Fats (Beta Oxidation) Steps: 1. Fat is broken down into glycerol and free fatty acids 2. The free fatty acids go through a process called beta-oxidation, this is when the fatty acids are broken down in the mitochondria to create Acetyl CoA 3. The Acetyl CoA enters the Krebs Cycle (follows the same path as glucose) - More ATP can be created from fatty acids than from glucose - Meaning that in long-duration exercise fatty acids are used more Advantages Disadvantages - it can last for a few hours - relies on oxygen consumption Example Sport: Marathon 3.3.10 - Discuss the characteristics of the three energy systems and their relative contributions during exercise (Limit to: fuel sources, duration, intensity, amount of ATP production and by-products) ATP-PC Lactic Acid Aerobic System Fuel Source Creatine phosphate Glucose Glucose, fats, and proteins Duration 10-15 seconds 1-2 minutes Up to 2 hours Intensity Maximal Maximal Sub-maximal ATPs 1 ATP 2 ATPs 36-38 ATPs By-Product Phosphate and creatine Lactic Acid (Carbon dioxide and water) Re-synthesis Very quickly Quickly Slowly 3.3.11 - Evaluate the relative contribution of the three energy systems during different types of exercise Relative Contribution of each Energy System (%) : Sport/Activity ATP-PC Lactic Acid Aerobic System Baseball 80 15 5 Swimming (400m) 20 40 40 Walking 0 5 95 Golf Swing 95 5 0 Football 90 10 0 Rowing 20 30 30