HUN 3224 Final Study Guide Test 1 Carbohydrates CHO 1 Digestion and Absorption a Monosaccharides disaccharides oligosaccharides polysaccharides Know names what they are made of bonds and examples of each You do not have to memorize structures i Monosaccharides are the most simple of CHOs containing only one sugar molecules 1 Example Glucose Fructose and Galactose a These are hexose sugars meaning they have 6 carbons ii Disaccharides are simple sugars as well but contain two sugar molecules 1 Maltose Glucose Glucose 2 Lactose Glucose Galactose 3 Sucrose Glucose Fructose iii Oligosaccharides are complex sugars and contain 3 10 sugar molecules These molecules are bound together by glycosidic bonds 1 1 4 bonds are digested by the body 2 1 4 bonds and 1 6 bonds cannot be digested iv Polysaccharides are the largest of the complex sugars and contain more than 10 sugar molecules up to hundreds of sugar molecules These molecules are also bound by glycosidic bonding 1 Starch storage form of CHO in plants a Amylose dissolves in H2O i Glucose linked by 1 4 bonds ii Linear molecule b Amylopectin i Branches chain polymer ii Glucose linked by 1 1 4 long straight chains 2 1 6 branches 2 Glycogen storage form of CHO is animals a Liver b Muscle c Highly branched d Energy source i Glycogenolysis 3 Fiber a Non digestible plant polysaccharides i 1 4 glycosidic linkages can t be broken down by our bodies b Defined by USDA i Dietary fiber found in plants ii Functional fiber isolated extracted or manufactured and has beneficial effects c Types i Insoluble does not dissolve in H2O 1 Decrease transit time transit time is the time it takes for us to poop our food if we decrease this time then it can understood as fast removal 2 Clears out body and helps prevent colon cancer 3 Lower absorption of fats since it leaves the body so quickly Increase fecal bulk lots of poop ii Soluble can dissolve in H2O Increases transit time takes longer to travel thru GI tract iii Glycemic Index GI how fast food increases blood sugar 4 1 levels 1 Low GI foods will increase blood glucose levels slowly and delays the movement of food d Fermented by bacteria in colon and produces hydrogen methane gas and CO2 together making farts This stimulates the production of good bacteria probiotics e DRI men f DRI women i 19 50 y o 38 g ii 51 y o 30 g i 19 50 y o 25 g ii 51 y o 21 g g Benefits of fiber i Anti carcinogenic anti cancer properties ii Negative correlation with mortality rates associated with heart disease 1 Cholesterol absorption 2 Fat absorption b Carbohydrate digestion what happens in the mouth in the small intestine iii Postprandial insulin response influence plasma glucose i In the mount we have salivary amylase an enzyme used to breakdown CHOs 1 4 bonds but cannot breakdown 1 6 bonds Although salivary amylase s action is incomplete because the enzyme becomes inactive upon entering the stomach due of the acidic conditions HCl ii As the CHOs reach the small intestine pancreatic amylase is secreted via the Sphincter of Oddi This is also where bile pancreatic lipase and bicarbonate all enter the small intestine c Understand what happens at the brush border and how Monosaccharides are transported in and out of cells i The brush border otherwise known as microvilli is where enterocytes are located CHOs are broken down into monosaccharides glucose fructose or galactose These simple sugars are absorbed into the enterocytes and enter the hepatic portal system venous system where they are transported to the liver to be dispersed throughout the body or stored as glycogen 1 Glucose and Galactose are both taken at enterocyte of small intestine by SGLT1 S means it is sodium dependent 2 Fructose is transported via GLUT5 ii Mechanisms of Transport 1 Passive Diffusion a Does not require energy b Limited by concentration gradient c Usually allows only very small particle to pass water and small fatty acids 2 Facilitated Diffusion a Does not require energy but does require a transport protein i Intergral membrane protein acts as a transport protein b Rate determined by i Concentration gradient ii Amount of carrier transporter protein available iii How fast the enzyme changes shape iv How fast the enzyme interacts with the molecule 3 Active Transport a Requires energy in the form of ATP because it is usually pumping against a concentration gradient b Also requires a carrier protein relies on Na i Ex Na K pump for every 2 K that enters the cell 3Na leave the cell This allows for the Na to be ready for carrier protein 4 Transport Proteins a Albumin i Major transport protein ii Maintains osmotic pressure 1 If albumin levels are low fluid leaves the bloodstream and causes a buildup in the interstitial space which creates edema b Transferrin c Lipoproteins i Transports IRON d Glucose Transporters i Carry various lipid cholesterol components to tissues i GLUT1 transports glucose to erythrocyrtes and placenta ii GLUT2 responsible for the glucose transport across basolateral membrane of enterocytes iii GLUT3 glucose to brain iv GLUT4 transports glucose into the cell across phospholipid bilayer at heart muscle fat and is dependent on insulin v GLUT5 responsible for fructose absorption at small intestine vi GLUT6 glucose transport across spleen and brain but GLUT3 is main transporter for brain vii GLUT7 unknown viii GLUT9 10 transport in the liver ix SGLT1 uptake of glucose and galactose at enterocytes of small d What happens if we have an enzyme deficiency intestine i Then the process in which the enzyme is used for will not continue efficiently or the body will simply produce more of the enzyme s e Know non digestible carbohydrates know examples why they are non digestible and what happens to them in the large intestine i Non digestible CHOs can be fibers or CHOs with either 1 4 or 1 6 bond linkages The large intestine has bacteria that breaks down these CHOs and also produces Vitamin K and some B Vitamins THERE IS A LARGE PICTURE WITH ALL OF THIS AT 2 Glycolysis Krebs HMP shunt THE END OF THIS SECTION a Glycolysis i Glycolysis is the breakdown of glucose for energy and occurs in the cytosol the liquid ii There is only one type of glycolysis but they can be understood in two ways portion of the cell 1 Anaerobic glycolysis a This is when glucose turns into pyruvate and due to the lack of oxygen it then turns into lactose b When there is no oxygen there is no electron transport chain processes therefore all of the by products that were produced such
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