Stephanie'sChapter15

__Ingestion and Digestion__ __15.1 Specific Action and Reactions Take Place Along The Digestive Track (pages393-394)__ Esophagus – a tube made of two layers or muscles; the outer layer runs length wise, the inner layer muscles run circular; located at the mouth of the stomach. Stomach – is the digestive organ located between esophagus and the small intestine __15.2 Chemical Digestion Reduces Large Food Molecules to Smaller, Absorbable Molecules (pages 394-396)__ Small intestine - a tube about six meters long that absorb food molecules. The molecules move through the intestine wall and are then carried in the blood stream When large food particles enter the small intestine they are broken down by digestive enzymes. __15.3 Absorption Takes Place in the Small Intestine (pages 396 and 397)__ Lymphatic system - system of vessels that transports fluid called lymphatic from the body tissue to blood

__15.4 The Large Intestine Absorbs Water (p 397)__ No food is absorbs in the large intestines, just water. Anus – a sphincter muscle where feces exits the body __Cellular Respiration__ __15.5 Cellular Respiration Release Energy from Food Molecules (p401)__ __15.6 Glycolysis Begins the Energy-Yielding Process (p402-p403)__ __15.7 The Kerb Cycle Completes the Breakdown of Glucose(p403-p404)__ __15.8 The Electron Transport System Packages Energy from Glucose as ATP(p404)__ Steps of Cellular Respiration 2. Kerb Cycle – the cycle in cellular respiration that completes the breakdown of intermediate products of glycolysis, releasing energy; also a source of carbon skeletons for use in biosynthesis reactions 3.Electron Transport System –the process in which electrons are transferred from one carrier molecule to another in photosynthesis and in cellular respiration; result in storage of some of the energy in ATP molecules __15.9 The Krebs Cycle Plays a Central Role in Cellular Metabolism(p405, p406)__ i. Glycerol is converted to 3-carbon sugar ii. Fatty acids are broken down to acetic acid and form acetyl CoA in the mitochondria Acetyl groups are broken down in the kerb cycle i. Amino group are then removed and the remaining carbon skeletons maybe down to the same 2-,3-,4-,5-carbom molecules formed in glycolysis and the Kerb cycle __15.10 Energy Releasing Processes Are Essential to Life (p409)__ Oxygen is required for cellular respiration, without oxygen the cycle slows a stop if it happens fermentation happens. Fermentation- the incomplete breakdown of food molecules, especially sugars, in the absence of oxygen
 * 1) Glycolysis – the initial breakdown of carbohydrates
 * 2) Glucose splits into two 3-carbon molecules some of the energy released is transferred to ATPs
 * 3) Creating carbon glucose fragments are formed
 * 1) During this cycle the 3 carbon glucose fragments are disassembled
 * 2) 6 carbon dioxide molecules are formed
 * 3) Hydrogen atoms are released
 * 1) Special molecules carry hydrogen atoms to this stage
 * 2) Each hydrogen atom is separated into an electron and protons
 * 3) The electrons and protons are transferred through many small steps to create water.
 * 4) This process makes ATP to store the energy to maintain the organism
 * 1) Carbohydrates, fats, and protein can all be used as a source of energy in cellular respiration
 * 2) Carbohydrates enter the carbon pathways as any 3-carbon sugars or as glucose
 * 3) Fats are separated into glycerol and fatty acids
 * 1) Protein first are decomposed to amino acids

__Nutrition__

__15.11 Dietary Habits Affect Health (p410)__ Function of the digestive system is to breakdown large molecules (food), and absorb the remaining smaller ones. People who eat gunk foods like processed sugar and animal fats results in malnourished people that are overweight __15.12 Lipids Are Concentrated Sources of Food Energy (p414-p416)__ The human body needs several types of nutrients like carbohydrates and fats that are the primary source of energy. Proteins are the source building materials and enzymes Vitamins and other element help to make enzymes work better and release energy from carbohydrates fats, and proteins Lipids are fats Fats are the most concentrated source of food energy Lipids aid in the metabolism of cholesterol and the absorption of Vitamins A, D, E, and K
 * Lipids or Fats ||  9kcals/gram  ||
 * Carbohydrates and Proteins ||  4kcals/gram  ||

Lipids that come from animals are linked to heart disease Lipids also supply fatty acids that the body cannot produce which supply important nutrients Saturated fat – a far containing fatty acids with no double-carbon bonds; usually are solid at room temperature (these are the bad ones) __15.13 Carbohydrates Provide Energy, Nutrients, and Fiber (p416-418)__ Fruits, vegetables and whole grains provide essential elements and vitamins for good health These are important to eat for dietary fiber and roughage. Dietary fiber cointians cellulose and other carbohydrate that are found in plants and unprocess foods these lead to healthier diestion and healther feces Refined sugars have no nutritional value and are called “empty kcals” Examples of refined sugars and sweeteners: sucrose, raw sugar, turbinado sugar, brown sugar, total invert sugar, corn syrup, honey, fructose, levulose, dextrose, lactose __15.4 Protein Provides the Body Framework (p418,p419)__ Protein is need to: Amino Acids: __15.5 Eating Disorder Are Widespread__ Anorexia nervosa – dieting become an obsession that can lead to dead; people with this disorder literally starve Bulimia – binge eating usually of junk foods, followed by induced vomiting to purge the body
 * 1) Repair and maintain body tissues
 * 2) For healthy growth and development
 * 3) Supplying amino acids
 * 1) Humans can only make 8 to 10 of the amino acids we need we must get the rest from food
 * 2) Eggs, milk, fish, soybean, cheese, meat and poultry are good sources of amino acids
 * 3) Grains and nuts are a good source of protein but have very little amino acids
 * People with these disorders have an extreme fear of being overweight even if they are very under weight
 * Believed to be psychiatric disorders