HES 2823 1st Edition Lecture 3 Outline of Last Lecture I Carbohydrates A Monosaccharides B Disaccharides Outline of Current Lecture I Carbohydrates continued A Polysaccharides II Digestion III Blood Glucose Regulation Current Lecture I Carbohydrates CHO continued A Polysaccharides multiple monosaccharides hundreds that form complex carbohydrates 1 Starch glucose polymer a Two Types of Starch i Amylose straight chain of glucose 50 of human starch intake ii Amylopectin branched glucose remaining 50 of human starch intake b Plants store CHO as starch i Grains wheat bread and pasta corn rice oats ii Non grains potatoes c CO2 H20 C6H12O6 glucose O2 i The causal arrow represents plants undergoing photosynthesis ii Requires the presence of sunlight as an energy source iii C6H12O6 O2 CO2 H20 energy The equation works in both directions but in this instance the arrow represents man metabolizing food 2 Glycogen glucose polymer branched structure of glucose a How humans store CHO in the liver and muscle b Unimportant dietary substance These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II 3 Cellulose glucose polyer a All plants contain it b Indigestible fiber c Most common organic compound 4 Maltodextrose glucose polymer 10 glucose molecules a Not naturally occurring energy source b Partially digested starch c Manufactured CHO d Also referred to as maltodextrin on most food labels Digestion A The breaking of large molecules down into smaller molecules 1 In the case of CHOs polysaccharides are broken down into disaccharides which are further separated into monosaccharides B Gastrointestinal GI Tract 1 Food enters the mouth travels down the esophagus and into the stomach which has one entrance and one exit sphincter on each end 2 The partially digested food then enters the small intestine and travels through it until it reaches the large intestine and does the same 3 Finally the remaining food particles that could not be taken up as nutrients for the body reach the anus with its own sphincter and exit as feces 4 As food passes through the intestines nutrients are absorbed from the particles into the surrounding tissues 5 Small Intestine a Complex and simple CHOs such as starch sucrose lactose and fructose are present in food ingested by an individual b In the small intestine each of the polymers is broken down into monomers i Starch becomes glucose ii Sucrose becomes glucose and fructose iii Lactose becomes glucose and galactose iv Monosaccharides like fructose retain their forms c Mucosal cells surround the intestine and absorb or receive glucose galactose and fructose all monosaccharides d Digestion and absorption end once all of the nutrients have been retrieved from the passes food along the small intestine e Capillaries surround the mucosal cells and receive CHOs i These channels contain blood which carries nutrients ii After absorption into the blood the portal vein takes the blood to the liver which only releases glucose into the blood NOT galactose or fructose which are converted to glucose instead III iii The glucose infused blood then reaches cells where it becomes energy iv CHOs are all mostly the same humans can thrive on any CHO Blood Glucose Regulation A The brain and nerves require glucose B When an individual consumes food his blood glucose concentration increases because of the introduction of glucose from the food 1 The pancreatic hormone insulin also increases in the blood circulation and sends a message to cells to consume the glucose 2 Once the supply of glucose is depleted another pancreatic hormone glucagon increases in the blood and sends a message to cells to break down the glucagon preventing one s blood sugar or blood glucose concentration from reaching 0 3 If one s blood sugar did reach 0 death would result