ANSC 318 1st Edition Lecture 3 Outline of Last Lecture I. Compared Nonruminant, Ruminant, and Hindgut Fermenter GITs and Carbohydrate Digestion; Importance of Water Outline of Current Lecture II. Lipidsa. Definition and Energy Valueb. Classification and Structurec. Saturated and Unsaturated Fatty AcidsIII. Lipidsa. Enzymatic vs. Fermentativeb. Comparative NutritionIV. Proteinsa. Structure, Classifications, and Terminologyb. Amino Acidsc. Enzymatic Digestion in Small Intestined. Fermentative DigestionCurrent LectureLipids:-organic compounds that are insoluble in water, but soluble in organic solvents-high energy value:1. Lipid = 9.45 kcal of heat/gram2. Carbohydrate = 4.2 kcal of heat/gramLipids are 2.25 times more energy dense than carbohydrates and proteinClassifications:-Simple Lipids:1. True Fats: molecules where fatty acids are linked by ester bonds with glycerol; have glycerol backbone; high energy2. Waxes: molecules where fatty acids are linked by ester bonds with an alcohol other than glycerol; less digestible than true fat less energyStructure:-Triglyceride: molecule comprised of a glycerol backbone with 3 fatty acids attached by ester linkages-Monoglyceride: molecule comprised of a glycerol backbone with 1 fatty acid attached by an ester linkage-a triglyceride = 3 monoglycerides put togetherThese 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.Saturated vs. Unsaturated Fatty Acids:-Saturated: have no double bonds-as # of carbons increases melting point increases-Unsaturated: have one or more double bonds-as # of double bonds increases melting point decreases-written like C# of Carbon: # of double bonds (i.e. C16:0 or C18:2)-the more double bonds, the softer the fat is Enzymatic Lipid Digestion in the Small Intestine: **I. Triglyceride –lipase diglyceride +LCFA (long chain fatty acid)II. Dyglyceride –lipase monoglyceride + LCFAIII. Fatty acids are absorbed into the lymph systemIV. Enzymatic Digestion of lipids occurs in all speciesFermentative Digestion in Ruminants:I. Tryglycerides –hydrolyzation glycerol +LCFAII. Glycerol (3-carbon sugar) –fermentation VFA’sIII. Unsaturated LCFA –biohydrogenyzation saturated LCFAIV. Considerable dietary unsaturated LCFA are converted to saturated LCFA in ruminantsV. Triglycerides that bypass the stomach in ruminants can be enzymatically digested in small intestine-there are products specially made to bypass the rumen to get fat into the small intestineComparative Lipid Digestion:Nutrient/GIT site Pig Horse CowLipid Long chain fatty acids linked by ester bonds toglycerol; enzymatic and fermentative digestionSee pig See pigStomach No enzymatic or fermentativeNo enzymatic or fermentativeLots of fermentation to LCFA and glycerol; glycerol to VFA; biohydrogenization of unsaturated to saturated LCFASmall Intestine Lots of enzymatic digestion to LCFA and glycerol; absorption from small intestine lumenLots of enzymatic digestion to LCFA and glycerol; absorption from small intestine lumenLimited enzymatic digestion to LCFA and glycerol; absorption from small intestine lumenLarge Intestine/Cecum Limited fermentation Limited fermentation Limited fermentationProtein:Structure:I. Common feature of proteins: basic structure is comprised of amino acidsII. Amino acids contain an amine group and carboxyl groupIII. 22 amino acids are commonly found in proteinsIV. Amino acids are linked by peptide bondsV. Composition of amino acids in a protein molecule determine its structure/functionClassification:I. Simple Proteins: yield only amino acids (AA) on hydrolysis (breakdown)a. Albumins (i.e. serum, egg, milk proteins)b. Globulins (antibodies)II. Fibrous Proteins: connective tissuea. Collagen (major protein of connective tissue)b. Elastin (tendons, arteries)III. Conjugated Protein: (contain nonprotien elements)a. Glycoprotein (protein and carbohydrate)**b. Lipoprotein (protein and lipid)**c. Metalloprotein (protein and minerals)**Terminology:I. True Protein: protein composed of AA **\II. Nonprotein Nitrogen (NPN): compounds that are not true protein in nature, but contain N and can be converted to protein by bacterial action **III. Digestible Protein: fraction of protein that an animal can digestIV. Essential AA: AA that are not synthesized in animal tissues in sufficient amounts to meet metabolic needsV. Degradable Intake Protein (DIP): fraction of feed protein that is digested in the rumen (ammonia)VI. Undegradable Intake Protein (UIP): fraction of feed protein that bypasses the rumen to the small intestines for enzymatic digestionAmino Acids:Essential Amino Acids:-phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, arginine, leucine, and lysine-PVT TIM HALL-body cannot make enough of these AANon-essential Amino Acids:-alanine, asparagine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, hydroxyproline, proline, serine, and tyrosineProteolytic Enzymes:I. Inactive Pepsinogen is secreted into stomach and converted to pepsin by acidic pHII. Trypsinogen is secreted by the pancreas into the small intestine and converted to trypsin by enterokinaseIII. Enterokinase is secreted by the cells of the duodenumIV. Chymotripsinogen is secreted by pancreas into the small intestine and converted to chymotrypsin by trypsinV. Dipeptidases are secreted by cells of small intestinesVI. Procarboxypeptidase is secreted by pancrease into the small intestine and converted to carboxypeptidase Fermentative Digestion of Protein:Protein Digestion in the Rumen:I. Microorganisms in the rumen hydrolyze most feed protein to peptides and AAII. AA in rumen can then be further degraded to ammonia, organic acids, or carbon dioxideIII. Ammonia in the rumen can be either absorbed from the rumen, or used by microbes to synthesize microbial proteinIV. Microbial protein passes to small intestine where it can be enzymatically digestedV. Dietary protein hydrolyzed in the rumen is called degraded intake protein (DIP) feed is changed, then absorbedVI. Dietary protein that escapes to the small intestines is called undegraded intake protein (UIP) what you feed is
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