HNF 461 1st Edition Lecture 28 Outline of Last Lecture I Conditionally Indispensible Amino Acids II Digestion in the Stomach III Digestion in the Small Intestine IV Key Enzymes Involved in Protein Digestion V Protein Absorption VI Intestinal Amino Acid Use VII Functions of Amino Acids in Intestinal Cells VIII Sources of Protein Outline of Current Lecture I Amino Acid Metabolism Generally II Liver III Liver Protein Synthesis IV Liver Nitrogen Containing Compound Synthesis a Gluathione b Carnitine c Creatine d Carnosine e Choline V Anabolism of Amino Acids VI Central Dogma Current Lecture Hepatic Amino Acid Metabolism Pt 1 1 Amino Acid Metabolism Generally a Amino acids from cell breakdown or from diet enter the amino acid pool in the cell b Amino acids are used in a variety of metabolic processes 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 i Make proteins ii Contribute to energy metabolism TCA Cycle iii Contribute to nitrogen containing compounds iv Minor fat production aren t a main contributor v Glucose production c Deamination removal of amino group in the form of ammonia i Ammonia travels to the liver to contribute to synthesis of urea which is excreted via urine 2 Liver a Dietary intake of protein 100 40 used by intestinal cells b Remaining 60 of dietary protein travels to the liver and half of this amount is absorbed by the liver so 30 of total dietary protein intake i Only 20 of this will be used for protein and N containing compound synthesis 6 of total dietary protein c Remaining 30 travels to non liver tissue heart muscle d Intestine and liver are the major consumers of amino acids e Only a small percentage of dietary amino acids will be used for protein N containing compound synthesis a large percentage will be used for energy metabolism processes 3 Liver Protein Synthesis a Some proteins synthesized remain in liver ex albumin b Some proteins synthesized in liver travel to plasma 4 Liver Nitrogen Containing Compound Synthesis a Gluathione tripeptide antioxidant responsible for maintaining redox homeostasis b Carnitine made from lysine in the body but also widely available in food sources responsible for long chain fatty acid transport from cytosol to mitochondria for betaoxidation c Creatine Synthesized from arginine glycine and methionine creatine phosphate responsible for short term energy and the recycling of ADP to ATP i Creatinine metabolic product of creatine indicator of lean body mass through measurement in urine d Carnosine Most abundant in the muscle and can store histidine functions as a buffer and maintains the osmolarity in muscle cells e Choline synthesized in the body from serine and 3 methyl groups also get through food in the form of lecithin part of acetylcholine 5 Anabolism of Amino Acids a Biogenic amines b Peptide hormones amino acid derived hormones c Plasma proteins albumin and globulin proteins d Structural proteins collagen e Enzymes f Immunoproteins antibodies g Transport proteins 6 Central Dogma a Protein Synthesis DNA RNA protein b Transcription mRNA synthesis c Translation protein synthesis d Elongation Process of Protein Synthesis i Our body makes proteins by adding one amino acid at a time ii 20 amino acids required to make a protein iii If one amino acid is missing elongation will stop formation of nonfunctional short proteins that will be degraded quickly in the body
View Full Document
Unlocking...