ANSC 303 1st Edition Lecture 18Outline of Last Lecture I. Intro to ProteinsII. Role/Function of ProteinsIII. Proteins in Animal DietsA. MonogastricB. RuminantsIV. Proteins and Amino AcidsV. AA structureVI. AA Structural IsomersVII. Classification of AAA. Classification depends on:B. Classification of R groups depends on:C. Nonpolar, aliphatic R groupD. Aromatic R groupE. Positively charged R groupF. Polar, uncharged R groupG. Negatively charged R groupVIII. Essentiality A. EssentialB. NonessentialIX. Protein Structurea. Key levels of organizationb. Primaryc. Secondary d. Tertiary e. Quaternary X. Denaturation of ProteinOutline of Current Lecture I. Crude ProteinII. DigestionThese 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.III. Protein Digestion - Stomach A. HCL secretion B. PepsinIV. Protein Digestion - Small IntestineV. Pancreatic PeptidesA. Trypsin B. ChymotrypsinC. CarboxypeptidaseVI. Brush Border EnzymesA. AminopeptidaseB. DipeptidaseCurrent LectureI. Crude Proteina. Value listed on feed tagsb. Chemically determines by analysis of a sample for Nc. Average composition of protein = 16% Ni. Factor of 6.25 used to convert %N in a sample to CP ii. CP = N x 6.25d. Tells nothing about protein quality II. Digestiona. Both begin digestion in the stomach b. Continue the majority of digestion in the small intestinei. Absorption of:1. Di peptides2. Tri peptides3. Amino acidsc. Difference: modification the rumen microbes make to the dietary proteini. Protein that enters the small intestine is different from what is fedd. Challenge: whole proteins are not absorbede. Solution: digestive enzymesi. Secreted as inactive pre-enzymesii. Break bondsiii. Create free AA and small peptides for absorptionf. Digestion begins in the stomach III. Protein Digestion - Stomach a. HCL secretion i. Parital cells in fundic regionii. Denatures 4, 3, 2 structuresiii. Peptide bonds unaffectediv. Activates pepsinogen v. Pepsinogen, add HCl, leads to pepsinb. Pepsini. Endopeptidase1. Cleaves peptide bonds on amino side of aromatic AA2. Leads to peptide fragmentsIV. Protein Digestion - Small Intestinea. Mixture from stomach further digested by pancreatic enzymesb. Pancreatic peptidases (proenzymes)i. Trypsinogenii. Chymotrypsinogeniii. Procarboxypeptidases A and Biv. Proelastasev. Collagenasec. Proenzymes must be activated by trypsini. Trypsin is activated, then activates everyone elseii. Trypsin also activates itselfV. Pancreatic Peptidesa. Trypsin i. Autocatalyticii. Endopeptidaseiii. Peptide bond on carboxyl side off basic AAb. Chymotrypsini. Endopeptidaseii. Peptide bond on carboxyl end of aromatic AAc. Carboxypeptidasei. Exopeptidaseii. Carboxyl terminal endiii. Zn dependentVI. Brush Border Enzymesa. Aminopeptidasei. Exopeptidaseii. Cleaves from amino terminal endb. Dipeptidasei. Cleaves bond between dipeptidesii. Enzyme also in the
View Full Document
Unlocking...