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 Lipids a Definition and Energy Value b Classification and Structure c Saturated and Unsaturated Fatty Acids III Lipids a Enzymatic vs Fermentative b Comparative Nutrition IV Proteins a Structure Classifications and Terminology b Amino Acids c Enzymatic Digestion in Small Intestine d Fermentative Digestion Current Lecture Lipids organic compounds that are insoluble in water but soluble in organic solvents high energy value 1 Lipid 9 45 kcal of heat gram 2 Carbohydrate 4 2 kcal of heat gram Lipids are 2 25 times more energy dense than carbohydrates and protein Classifications Simple Lipids 1 True Fats molecules where fatty acids are linked by ester bonds with glycerol have glycerol backbone high energy 2 Waxes molecules where fatty acids are linked by ester bonds with an alcohol other than glycerol less digestible than true fat less energy Structure 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 together 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 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 LCFA III Fatty acids are absorbed into the lymph system IV Enzymatic Digestion of lipids occurs in all species Fermentative Digestion in Ruminants I Tryglycerides hydrolyzation glycerol LCFA II Glycerol 3 carbon sugar fermentation VFA s III Unsaturated LCFA biohydrogenyzation saturated LCFA IV Considerable dietary unsaturated LCFA are converted to saturated LCFA in ruminants V 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 intestine Comparative Lipid Digestion Nutrient GIT site Pig Lipid Long chain fatty acids linked by ester bonds to glycerol enzymatic and fermentative digestion Stomach No enzymatic or fermentative Small Intestine Large Intestine Cecum Lots of enzymatic digestion to LCFA and glycerol absorption from small intestine lumen Limited fermentation Horse See pig Cow See pig No enzymatic or fermentative Lots of fermentation to LCFA and glycerol glycerol to VFA biohydrogenization of unsaturated to saturated LCFA Limited enzymatic digestion to LCFA and glycerol absorption from small intestine lumen Limited fermentation Lots of enzymatic digestion to LCFA and glycerol absorption from small intestine lumen Limited fermentation Protein Structure I Common feature of proteins basic structure is comprised of amino acids II Amino acids contain an amine group and carboxyl group III 22 amino acids are commonly found in proteins IV Amino acids are linked by peptide bonds V Composition of amino acids in a protein molecule determine its structure function Classification 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 tissue a 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 digest IV Essential AA AA that are not synthesized in animal tissues in sufficient amounts to meet metabolic needs V 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 digestion Amino Acids Essential Amino Acids phenylalanine valine tryptophan threonine isoleucine methionine histidine arginine leucine and lysine PVT TIM HALL body cannot make enough of these AA Non essential Amino Acids alanine asparagine aspartic acid cysteine cystine glutamic acid glutamine glycine hydroxyproline proline serine and tyrosine Proteolytic Enzymes I Inactive Pepsinogen is secreted into stomach and converted to pepsin by acidic pH II III IV V VI Trypsinogen is secreted by the pancreas into the small intestine and converted to trypsin by enterokinase Enterokinase is secreted by the cells of the duodenum Chymotripsinogen is secreted by pancreas into the small intestine and converted to chymotrypsin by trypsin Dipeptidases are secreted by cells of small intestines 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 AA II AA in rumen can then be further degraded to ammonia organic acids or carbon dioxide III Ammonia in the rumen can be either absorbed from the rumen or used by microbes to synthesize microbial protein IV Microbial protein passes to small intestine where it can be enzymatically digested V Dietary protein hydrolyzed in the rumen is called degraded intake protein DIP feed is changed then absorbed VI Dietary protein that escapes to the small intestines is called undegraded intake protein UIP what you feed is absorbed