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12. Metabolism

12. Metabolism. Goals of metabolism Metabolic Overview Key molecules Metabolic Pathways – metabolic mainstreet Fat and Protein Metabolism Summary. What is on a nutrition label?. Carbohydrates – starch and sugars Lipids – animal fat and vegetable oil (triglycerides) Protein

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12. Metabolism

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  1. 12. Metabolism • Goals of metabolism • Metabolic Overview • Key molecules • Metabolic Pathways – metabolic mainstreet • Fat and Protein Metabolism • Summary What is on a nutrition label? Carbohydrates – starch and sugars Lipids – animal fat and vegetable oil (triglycerides) Protein some vitamins (A, C) and minerals (Na, Ca, Fe)

  2. Nutrition Labels – peanut butter Serving size: 2Tbs (32g) (35 servings per container) Calories 190: calories from fat 130 Total fat 16g (25%) saturated fat3g (16%) trans fat0g cholesterol0mg (0%) Calories Fat ~ 9 Cal/g Carbohydrate & Protein ~ 4 Cal/g Sodium 110mg (5%) Total carbohydrate 7g (2%) dietary fiber2g (12%) sugars 3g Protein 7g (3%) vitamin A0%vitamin C 0% calcium 0%iron4%

  3. Goals of metabolism 1. Catabolism Convert food (digestion of carbohydrates, lipids, protein) & storage molecules (hydrolysis of glycogen (liver & Muscle) triglycerides = fat (adipose) protein (all cells - only during fasting state) …. into energy (ATP) 1) digestion/hydrolysis 2) Metabolic Mainstreet 2. Anabolism Convert building blocks (amino acids, fatty acids, sugars) into macromolecules. 1) translation – making proteins (all cells) 2) storing glucose – making glycogen (liver & muscle) 3) storing fatty acids – making fat (liver & adipose – stored in adipose)

  4. Digestion/Hydrolysis Breaking down macromolecules into their original units ….. a) Sugars b) amino acids c) fatty acids d) nucleic acids The digestion/hydrolysis of lipids produces …. The digestion/hydrolysis of carbohydrates produces …. The digestion/hydrolysis of protein produces ….

  5. 1. Catabolism Convert food & storage molecules (carbohydrates, lipids, protein) …. into energy (ATP) 1) digestion/hydrolysis 2) Metabolic Mainstreet carbohydrates: amylase (saliva & intestines) starch → maltose & glucose sucrase/invertase sucrose → fructose & glucose (intestines) lactase (absent in lactose intolerance) lactose → galactose& glucose (intestines)

  6. 1. Catabolism Convert food & storage molecules (carbohydrates, lipids, protein) …. into energy (ATP) 1) digestion/hydrolysis protein: variousproteases (stomach & intestines) proteins → amino acids fat: lipase (intestines & adipose) triglycerides → glycerol + fatty acids

  7. amino acids none can be reclaimed from the bodies proteins during the fasting state. Glycogen liver & muscle Fat adipose Food Carbohydrates Fat Protein Fatty acids & glycerol Glucose Fructose Galactose Storage Digestion into … By ….. enzyme amylase lactase sucrase Lipase proteases

  8. What are the 2 goals of Metabolism? Which goal does catabolic activity address? a) energy b) molecule construction What molecules are produced by Anabolic Metabolism? Which of the following molecules are made during catabolic metabolism? a) ATP b) NAD+ c) protein d) ADP

  9. What is a pathway? A sequential set of cellular reactions? Each reaction step is catalyzed by a different enzyme? The pathway produces product(s) that is/are useful to the cell ? Glycolysis Glucose + 2ADP + 2NAD+ ↓ 2 pyruvate + 2ATP + 2NADH acetylCoA Oxidative Phosphorylation & more ATP Useable energy for cell Citric acid cycle

  10. Metabolism overview Catabolism Proteins Carbohydrates Lipids ↓ ↓ ↓ amino acids glucose fatty acids oxidative deamination glycolysisb-oxidation ↓ ↓ ↓ NAD+ → NADH2NAD+ → 2NADH 7NAD+ → 7NADH 2ADP → 2ATP 7FAD → 7FADH2pyruvate ↓ acetylCoA Citric Acid Cycle ↓ 3NAD+ → 3NADH & 1FAD → 1FADH2 Oxidative Phosphorylation ↓ ADP → ATP NADH → NAD+ Waste: CO2 NH4+

  11. High Energy Molecules Used for anabolic reactions, muscle activity, active transport Macromolecules: Protein – Carbohydrate – Fat Fuels: amino acids – sugars (glucose) – fatty acids Coenzymes NADH & FADH2 Acetyl CoA ATP Energy stored Can burn for energy or store for later use For immediate conversion Can burn for energy or store for later use Immediate use Low Energy Molecules needs to be recycled to high energy form by Catabolism NAD+/FAD ADP (or AMP) Waste: needs to be removed CO2 NH4+

  12. ATP, ADP, and AMP ATP is the ‘immediate’ energy currency of the cell. GTP and UTP also provide energy in specific cases ATP + H2O → ADP + Pi(phosphate group) + energy Adenosine triphosphate - ATP anabolic consumes ATP/energy catabolic produces ATP/energy ATP provides energy for ….. 1) anabolism (makes protein, DNA, glycogen, fat) 2) Muscle activity 3) Active transport (regulates what’s in cells) Adenosine diphosphate - ADP HO-

  13. Metabolism overview Catabolism 1. Catabolism Pathways that convert the energy in our food into reduced coenzymes – NADH and FADH2. Proteins Carbohydrates Lipids ↓ ↓ ↓ amino acids glucose fatty acids oxidative deamination glycolysisb-oxidation ↓ ↓ ↓ NAD+ → NADH2NAD+ → 2NADH 7NAD+ → 7NADH 2ADP → 2ATP 7FAD → 7FADH2pyruvate ↓ acetylCoA Citric Acid Cycle ↓ 3NAD+ → 3NADH & 1FAD → 1FADH2 Oxidative Phosphorylation ↓ ADP → ATP NADH → NAD+ Waste: CO2 NH4+

  14. Pathways that convert the energy in our food into reduced coenzymes – NADH and FADH2. Metabolic Main Street: produces 36 ATP molecules for each glucose molecule burned

  15. Glycolysis Citric Acid Cycle & Oxidative Phosphorylation makes aerobic ATP DNA synthesis Protein synthesis

  16. Aerobic vs. Anaerobic What is the difference? 2ATP per glucose bonus ATP in muscle beyond O2 supply 36ATP per glucose Needs O2 This is used to supplement energy output during intense muscle activity Aerobic is standard in all cells

  17. Metabolism overview Catabolism 1. Catabolism Pathways that convert the energy in our food into reduced coenzymes – NADH and FADH2. Proteins Carbohydrates Fat ↓ ↓ ↓ amino acids glucose fatty acids oxidative deamination glycolysisb-oxidation ↓ ↓ ↓ NAD+ → NADH2NAD+ → 2NADH 7NAD+ → 7NADH 2ADP → 2ATP 7FAD → 7FADH2pyruvate ↓ acetylCoA Citric Acid Cycle ↓ 3NAD+ → 3NADH & 1FAD → 1FADH2 Oxidative Phosphorylation ↓ ADP → ATP NADH → NAD+ Waste: CO2 NH4+

  18. Citric Acid Cycle acetylCoA + 3NAD+ + FAD ↓ 2CO2 + 3NADH + 1FADH2 The acetylCoA can come from the oxidation of … glucose (glycolysis) fatty acids (b-oxidation) amino acids (oxidative deamination)

  19. Metabolism overview Catabolism Oxidative Phosphorylation Proteins Carbohydrates Lipids ↓ ↓ ↓ amino acids glucose fatty acids oxidative deamination glycolysisb-oxidation ↓ ↓ ↓ NAD+ → NADH2NAD+ → 2NADH 7NAD+ → 7NADH 2ADP → 2ATP 7FAD → 7FADH2pyruvate ↓ acetylCoA Citric Acid Cycle ↓ 3NAD+ → 3NADH & 1FAD → 1FADH2 Oxidative Phosphorylation ↓ ADP → ATP NADH → NAD+ or FADH2 → FAD Waste: CO2 NH4+

  20. The NADH/FADH2can come from … glycolysis b-oxidation oxidative deamination Citric Acid Cycle Goes back to other pathways The Oxidative Phophorylation pathway Is located in the inner membrane of the mitochondria Oxidative Phosphorylation NADH or FADH2 & O2 ↓ NADH → NAD+ 3ADP →3ATP or FADH2→ 1FAD 2ADP → 2ATP & O2 →H2O Delivered to …. cell via Hb mitochondria via Mb aerobic only Supplies energy to Cell

  21. Aerobic vs. Anaerobic What is the difference? Glycogen 2ATP per glucose bonus ATP in muscle beyond O2 supply 36ATP per glucose Needs O2 Stored in muscle to provide extra glucose which is converted into ATP via Glycolysis for anaerobic activity. Resting muscle (aerobic) burns more fat than glucose. This is used to supplement energy output during intense muscle activity Aerobic is standard in all cells

  22. [Glucose] in the blood Last meal? a) lunch b) breakfast c) yesterday If a … breakfast? a) yes b) no ~ hours of fast ~ 2 hours (lunch to now) ~ 6 hours (breakfast to lunch) ~ 12 hours (dinner to breakfast) ~ 20 hours (dinner to now) Graph of [Glucose] in blood vs. time after last meal

  23. Insulin – glucose into muscle/adipose Glucagon – signal for fasting state adipose exports fatty acids liver exports glucose [Glu] blood Meal Liver Glycogen broken down to provide glucose Fed 60 – 100 mg/dL ~2 hrs ~12 hrs ~ hours of fast ~ 2 hours (lunch to now) ~ 6 hours (breakfast to lunch) ~ 12 hours (dinner to breakfast) ~ 20 hours (dinner to now)

  24. Glucose Transporter Liver Cell Membrane Liver Glycogen Stores & Fasting State Blood Fasting State = liver provides [glucose] to blood to keep ~ constant [glucose] 60 - 100 mg/dL Liver Cell Cytoplasm glycogen → glucose

  25. high glycemic index – low fat diet diabetic Atkins – low carb diet [Glu] blood insulin resistance (metabolic syndrome) Meal Fed 60 – 100 mg/dL ~2 hrs ~12 hrs

  26. early long term ~ 3 days late Lipolysis Brain uses Ketone bodies Protein conserved Fasting State Glycogen broken down to provide glucose glycogenolysis Protein broken down to make glucose gluconeogenesis

  27. current Fats sugars Na use sparingly 2001 Fruits 2 cups weekly Vegetables 3 cups weekly Milk 3 cups (Ca rich foods– low fat) Fats use sparingly Meat & beans: lean meats more fish, beans, nuts, peas, seeds Grains 8 oz.4 oz. whole grain Dairy Meat, Fish 2-3 Eggs, Beans 2-3 1992 Vegetables 3-5 Fruits 2-4 Bread, cereal, rice, pasta 6-11

  28. Red meat, butter, white rice, bread, potatoes, pasta, sweets Willett, Walter (2005). Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating. Free Press. ISBN 0-7432-6642-0 Healthy Eating Pyramid use sparingly Dairy/Ca supp 1-2 Multiple vitamin Fish, poultry, eggs 0-2 Nuts & legumes 1-3 Vegetables (lots) Fruits 2-3 Whole grain Plant oils Exercise & weight control

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