1. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Metabolism: Transformations and Interactions Chapter 7

2. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Introduction  Energy  Heat  Mechanical  Electrical  Chemical  Stored in food and body  Metabolism  Release of energy, water, and carbon dioxide

3. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Chemical Reactions in the Body  Energy metabolism  How body obtains & uses energy from food  Cell type  Liver cells  Anabolism  Requires energy  Catabolism  Releases energy

4. Whitney & Rolfes – Understanding Nutrition, 12 th Edition A Typical Cell

5. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Chemical Reactions in the Body

6. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Chemical Reactions in the Body  Transfer of energy in reactions – ATP  Released during breakdown of glucose, fatty acids, and amino acids  Form of phosphate groups  Negative charge – vulnerable to hydrolysis  Provides energy for all cell activities  Coupled reactions  Efficiency  Heat loss

7. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Capture and Release of Energy by ATP

8. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Chemical Reactions in the Body  Enzymes  Facilitators of metabolic reactions  Coenzymes  Organic  Associate with enzymes  Without coenzyme, an enzyme cannot function

9. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy  Digestion  Carbohydrates – glucose (& other monosaccharides)  Fats (triglycerides) – glycerol and fatty acids  Proteins – amino acids  Molecules of glucose, glycerol, amino acids, and fatty acids  Catabolism  Carbon, nitrogen, oxygen, hydrogen

10. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy  Two new compounds  Pyruvate  3-carbon structure  Can be used to make glucose  Acetyl CoA  2-carbon structure  Cannot be used to make glucose  TCA cycle and electron transport chain

11. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy

12. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose  Glucose-to-pyruvate  Glycolysis  2 pyruvate molecules  Hydrogen atoms carried to electron transport chain  Pyruvate can be converted back to glucose  Liver cells and kidneys (to some extent)

13. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose

14. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose  Pyruvate’s options  Quick energy needs – anaerobic  Pyruvate-to-lactate (Cori cycle)  Slower energy needs – aerobic  Pyruvate-to-acetyl CoA

15. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose  Pyruvate-to-lactate  Pyruvate accepts hydrogens  Converts pyruvate to lactate  Occurs to a limited extent at rest  Produces ATP quickly  Mitochondrial ability  Accumulation of lactate in muscles  Effects  Cori cycle

16. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose

17. Glucose Uses energy (ATP) 2 Lactate Stepped Art In the liver: Fig. 7-7, p. 213

18. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose  Pyruvate-to-Acetyl CoA  Pyruvate enters mitochondria of cell  Carbon removed – becomes carbon dioxide  2-carbon compound joins with CoA becoming acetyl CoA – irreversible

19. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose

20. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose  Acetyl CoA’s options – 2 functions  Synthesize fats  Generate ATP through TCA cycle  Hydrogens – electron transport chain

21. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose

22. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glucose

23. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glycerol and Fatty Acids  Glycerol-to-pyruvate  Glycerol can be converted  Glucose  Pyruvate  Fatty acids-to-Acetyl CoA  Fatty acid oxidation  2-carbon units at a time then join with CoA  Hydrogens and electrons carried to electron transport chain

24. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glycerol and Fatty Acids

25. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Glycerol and Fatty Acids

26. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Amino Acids  Deamination of amino acids  Amino acids-to-energy  Several entry points in energy pathway  Converted to pyruvate (glucogenic)  Converted to acetyl CoA (ketogenic)  Enter TCA cycle directly (glucogenic)  Amino acids-to-glucose

27. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Breaking Down Nutrients for Energy – Amino Acids

28. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Final Steps of Catabolism  TCA Cycle  Inner compartment of mitochondria  Circular path  Acetyl CoA  Oxaloacetate – made primarily from pyruvate  Carbon dioxide release  Hydrogen atoms and their electrons  Niacin and riboflavin

29. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Final Steps of Catabolism

30. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Final Steps of Catabolism  Electron transport chain  Energy captures in ATP  Series of proteins  Electron “carriers”  Inner membrane of mitochondria  Electrons passed to next carrier  Join oxygen at end of chain – water released  ATP synthesis

31. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Final Steps of Catabolism

32. Whitney & Rolfes – Understanding Nutrition, 12 th Edition

33. Energy Balance – Feasting  Metabolism favors fat formation  Regardless of excess from protein, fat, or carbohydrates  Dietary fat to body fat is most direct and efficient conversion  Carbohydrate and protein have other roles to fulfill before conversion to body fat  Fuel mix

34. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Energy Balance – Transition from Feasting to Fasting  Glucose, glycerol, and fatty acids are used then stored  Fasting state draws on these stores  Glycogen and fat are released  Basal metabolism  Fasting vs. starving

35. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Energy Balance – Transition from Feasting to Fasting

36. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Energy Balance – Fasting  Carbohydrate, fat, and protein are all eventually used for energy  Begin with release of glucose and fatty acids  Acetyl CoA  Low blood glucose levels signal  Fat breakdown  Release of amino acids from muscles

37. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Energy Balance – Fasting  Glucose needs  Nervous system and red blood cells  Amino acids yielding pyruvate  Breakdown of body proteins  Shift to ketosis  Use fat to fuel brain  Ketone bodies  Slows the rate of body protein breakdown

38. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Energy Balance – Fasting

39. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Energy Balance – Fasting  Ketosis causes a loss of appetite  Slowing of metabolism  Hormones  Reduces energy output  Supports weight loss but not fat loss  Symptoms of starvation  Physical symptoms  Psychological symptoms

40. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Low-Carbohydrate Diets  Metabolism similar to fasting  Uses glycogen stores first  Gluconeogenesis when glycogen is depleted  Body tissues used somewhat even when protein provided in diet  Urine monitoring  Ketosis

41. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Highlight 7 Alcohol and Nutrition

42. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol in Beverages  Potential health benefits  Alcohols  Glycerol  Ethanol  Lipid solvents  Moderation  Definition of “drink”

43. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol in the Body  Alcohol’s special privileges  No digestion  Quick absorption  Slowing absorption  Stomach  Alcohol dehydrogenase  Small intestine  Priority over nutrients

44. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Arrives in the Liver  Liver cells  First to receive alcohol-laden blood  Alcohol dehydrogenase  Disrupts liver activity  Can permanently change liver cell structure  Rate of alcohol metabolism  Acetaldehyde  Acetate

45. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Arrives in the Liver

46. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Disrupts the Liver  Nicotinamide adenine dinucleotide (NAD)  Glycolysis  TCA cycle  Electron transport chain  Development of fatty liver  Damage to central nervous system  Inflammation of joints  Amino acid and protein metabolism

47. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Arrives in the Liver

48. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Arrives in the Liver  Immune system functioning  Alcohol interferes with drug metabolism  Microsomal ethanol-oxidizing system (MEOS)

49. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Arrives in the Brain  Sedates inhibitory nerves  Acts as central nervous system depressant  Blood alcohol levels and brain responses  Death of liver and brain cells  Depression of antidiuretic hormone (ADH)  Loss of body water  Loss of important minerals

50. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Arrives in the Brain

51. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol Arrives in the Brain

52. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol and Malnutrition  Can contribute to body fat and weight gain  1 ounce of alcohol represents 0.5 ounce of fat  Central obesity  Substituted energy  7 kcalories per gram  Nutrient displacement  B vitamins

53. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol’s Effects  Short-term effects  Excessive drinking  Heavy drinking  Binge drinking  Long-term effects  Third leading preventable cause of death in U.S.  Sobering up

54. Whitney & Rolfes – Understanding Nutrition, 12 th Edition Alcohol’s Effects