1 Monosaccharides Simple Sugars simplest form of carbohydrates C6H12O6 2 Disaccharides formed by condensation of 2 Monosaccharides digestion occurs HUN 3224 Test 1 Study Guide Digestion and Absorption Carbohydrates a Glucose Most abundant blood sugar b Fructose c Galactose in upper small intestine a Maltose glucose glucose b Sucrose glucose fructose c Lactose glucose galactose beta 1 4 bonds 3 Oligosaccharides 3 10 monosaccharide chain linked by alpha 1 4 bonds and 4 Polysaccharides 10 to 500 000 monosaccharide chain a Starch storage form of CHO in plants b Types i Amylose Glucose linked by a 1 4 bonds and is linear ii Amylopecin 1 Branched chain polymer 2 Linked by a a 1 4 long straight chains b a 1 6 branches 5 Glycogen storage form of CHO in animals liver and muscles 6 Fiber non digestible Carbohydrates plant polysaccharides a Dietary Fiber found intact and intrinsic in plants b Functional Fiber isolated extracted or manufactured c Soluble Fiber dissolves in water and increases digestive transit time d Insoluble Fiber doesn t dissolve in water decrease digestive transit time and increases fecal bulk e Fermented in Colon large intestine produces hydrogen gas methane and CO2 and promotes good bacteria 7 Digestion a Mouth i Salivary Amylase produced by salivary glands 1 digests a 1 4 bonds 2 NOT a 1 6 bonds disaccharides or oligosaccharides 3 HCL in stomach inactivates salivary amylase b Small Intestine comes in from stomach as Chyme i Pancreatic Secretions regulates pH ii Pancreatic amylase digests starch c Brush Border Enzymes microvilli Digestion Complete i Sucrase digests Sucrose ii Lactase digests Lactose iii Maltase digests Maltose iv Isomaltase digests Dextrins into glucose glucose 8 Absoprtion a Glucose and Galactose i Active Transport requires energy ii SGLT1 transports Glucose and Na into cell iii Utlizies the Na K pump to bring glucose galactose into the cell iv Enterocyte intestinal absorption cell Capillaries Hepatic Portal System Liver b Fructose i Facilitated diffusion by GLUT 5 type of glucose transporter ii Some is converted to glucose in enterocyte iii Transported to the liver Glycolysis Krebs HMP shunt 1 Glycolysis oxidation of glucose and energy production in cytosol Degraded into pyruvate a triose a Anaerobic without oxygen i glucose pyruvate lactate ii Net ATP 2 ATP from 2 ATP b Aerobic with oxygen i glucose pyruvate acetyl CoA Krebs Cycle ii Net ATP 14 ATP from 4NADH and 2 ATP 1NADH 3ATP c Rate Limiting Steps step in enzyme reaction that requires greatest i Step 1 Hexokinase Glucose Glucose 6 Phosphate requires energy ATP ii Step 3 Phosphofructokinase Fructose 6 Phosphate Fructose 1 6 bis Phosphate requires ATP ADP iii Step 10 Pyruvate Kinase Phosphoenolpyruvate pyruvate 2 Krebs Cycle Tr carboxylic Acid Cycle TCA Citric Acid Cycle ADP ATP a Amphibolic Pathway both anabolic and catabolic CHO proteins and fats all enter and become oxidized into CO2 H2O and energy b Location Mitochondria Matrix c Energy Production NADH 3ATP FADH 2ATP GTP 1ATP i Acetyl CoA 3 NADH 2 FADH 1 GTP 12 ATP total ii Pyruvate 4 NADH 2FADH 1 GTP 15 ATP total iii Glucose produces 2 Acetyl CoA molecules so it cycles twice in the 3 Total Energy produced from 1 Glucose Krebs Cycle 4 Pentose Phosphate Pathway HMP Shunt In the Cytosol generate NADPH and pentoses for the biosynthesis of fatty acids and nucleic acids Electron Transport Chain 1 Electron Transport Chain production of mitochondrial ATP a Oxidative Phosphorylation supplies energy from CHO Fatty acids and b Proton Pumps builds an electrostatic gradient across the membrane Amino acids i Oxidation NADH NAD 2H ii Phosphorylation ADP P ATP H i Complex I NADH dehydrogenase complex ii Complex III Cytochrome B C complex iii Complex IV Cytochrome oxidase complex c Electron Transporter transports electrons between complexes i Ubiquinone complex II transports electrons between complex I and III ii Cytochrome C transports electrons between complex III and IV d ATP Synthase Complex V transports protons across the inner mitochondrial membrane for phosphorylation of ADP to ATP ADP P ATP e Video about Electron Transport Chain Check it out http www youtube com watch v xbJ0nbzt5Kw 2 Why NADH produces 3 ATP and FADH2 produces 2 ATP NADH feeds its electrons into the electron transport chain at the beginning Complex I FADH2 feeds into the electron transport chain at Complex II at a lower energy level down the chain The high energy electrons from NADH have sufficient energy to result in 3 ATP whereas the lower energy electrons in FADH2 have only energy for 2 ATP The donated electrons are passed along the electron transport chain from high energy level to low energy level O2 is the final acceptor via Complexes I IV As the energy is given up protons H are pumped from the matrix of the mitochondria into the space between the inner and outer membranes of the mitochondria thus establishing a H concentration gradient The H then diffuse back through the ATP synthase 3 Thyroid Hormone uncouples proteins oxidative phosphorylation and halts ATP Synthase BMR weight loss a Hyperthyroidism too much thyroid hormone inefficient ETC increased b Hypothyroidism not enough thyroid hormone decreased BMR weight gain Gluconeogenesis 1 Gluconeogenesis Make glucose from non carbohydrate sources in the cytosol liver sometimes kidney Not exactly the reverse of Glycolysis due to non reversible steps a Beginning Products non carbohydrate sources Pyruvate Krebs Intermediates Amino Acids b End Products Glucose it requires ATP 2 Non reversible steps Steps 1 3 10 of Glycolysis Non reversible because a Acetyl CoA Pyruvate NOT possible b Pyruvate phosphoenol pyruvate Not possible c Bypass by formation of Oxaloacetate which can be phosphorylated to phosphoenol pyruvate 3 Why Gluconeogenesis a Makes Glucose when CHO is not available b Brain and CNS are dependent on Glucose as a nutrient c Clears lactate produce by muscles via Cori Cycle Glycogenesis Glycogenolysis 1 Glycogenesis Glucose Glycogen in the Liver Glycogen energy storage a Puts Glycogen back into the Muscle as a reserve for instant energy b Used when muscle glycogen stores are used up c Induced by i Insulin ii High Glucose iii Glucose 6 phosphate 2 Glycogenolysis Glycogen Glucose in the liver a Release stored Glycogen energy into the body b Induced by i Glucagon ii Low blood glucose iii Epinephrine exercise 3 First and Second Messenger a First Messenger Hormone body message sent to cell b Second Messenger cAMP received message
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