Today: Nutrition and Digestion Wed. Grizzly Bears

During digestion complex molecules are broken down and then used to build needed molecules and to produce energy

Food Pyramid based on 2,000 calories/day

Federal Food Subsidies vs Food Pyramid http://www.pcrm.org/magazine/gm07autumn/health_pork.html

Protein needed per day = 0.8g/kg of body weight So a 150 lb person needs 54 g or 2 oz of protein/day

20 amino acids

8 Essential Amino Acids

Many cultures combine these foods in their traditional diets: beans and rice, beans and corn, peanut butter on bread, soy and rice, lentils and bread or rice

The Calorie Restriction Society for people trying to live longer by eating fewer calories http://youtube.com/watch?v=YTQR7o9ap9Y

Regulation of Drosophila Life Span by Olfaction and Food-Derived Odors S Libert, J Zwiener, X Chu, W VanVoorhies, G Roman, S Pletcher Science Vol. 315:1133 - 1137 23 February 2007

Smelling food reduces life span in CR flies Calorie Restricted Flies Normal Diet Flies Fig 1

Calorie Restriction related websites: http://www.calorierestriction.org/ http://www.cbsnews.com/stories/2005/12/30/eveningnews/main1172297.shtml http://stke.sciencemag.org/cgi/content/full/sci;315/5815/1133 http://stke.sciencemag.org/cgi/content/full/sci;315/5812/584

Cause-Specific Excess Deaths Associated with Underweight, Overweight, and Obesity Flegal KM et al JAMA, November 7, 2007—Vol 298, No. 17 pg 2028-37 Overweight (BMI 25-30) people live longer than normal (BMI 18.5-25), underweight (BMI<18.5), or obese (BMI>30) people JAMA, November 7, 2007—Vol 298, No. 17 pg 2028-37

Fig 43.5 The Digestive System

Complex molecules are broken down and then used to build needed molecules and to produce energy

Animals take in complex molecules from the environment for energy production

Animal digestion occurs outside of our cells.

animal and fungal digestion occurs outside of our cells.

breaking large molecules into small molecules Fig 43.6 Physical digestion: liquefying of food Chemical digestion: breaking large molecules into small molecules

Chewing and adding saliva begins the process of liquification Fig 43.6 Chewing and adding saliva begins the process of liquification Amylase in mouth Amylase begins the chemical digestion of carbs

The primary function of the stomach is food storage Fig 43.8 The primary function of the stomach is food storage

In the stomach liquification continues. Fig 43.8 Pepsin in stomach Pepsin begins the chemical digestion of proteins.

Fig 43.5 The Digestive System

Fig 43.6 Most chemical digestion occurs in the first part of the small intestine

Fig 43.11 The small intestine has a large surface area to aid in absorbption of nutrients

Fig 43.11 Absorption in the Small Intestine

Fats and lipids move through the lymphatic system, which Fig 43.6 Fats and lipids move through the lymphatic system, which returns fluid to blood directly before heart small intestine Lymph vessel

Fig 43.5 The Digestive System

Fig 43.6

Tonight, “Plastic Garbage Island” 7pm in Welch 1.308 Today: Nutrition and Digestion Wed. Grizzly Bears Tonight, “Plastic Garbage Island” 7pm in Welch 1.308