Protein: Amino Acids Copyright 2005 Wadsworth Group, a division of Thomson Learning

Amino Acids Copyright 2005 Wadsworth Group, a division of Thomson Learning

Amino Acids Nonessential amino acids –a.k.a dispensable amino acids Essential amino acids –a.k.a indispensable amino acids Conditionally essential amino acids Copyright 2005 Wadsworth Group, a division of Thomson Learning

An Essential Amino Acid

Nonessential Amino Acids

Proteins Peptide bond

Proteins Dipeptide Copyright 2005 Wadsworth Group, a division of Thomson Learning

Proteins Tripeptide

Proteins Polypeptide Copyright 2005 Wadsworth Group, a division of Thomson Learning

Proteins Amino acid sequences Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein shape and function

Proteins Protein denaturation Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Digestion Stomach –HCl –Pepsinogen  pepsin Proenzyme Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Digestion Small intestine –Proteases Intestinal and pancreatic –Peptidases Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Digestion in the GI Tract

Protein Absorption Carriers Capillaries Absorption misconceptions –Enzyme/amino acid supplements Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Synthesis Delivering the instructions –DNA mRNA Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Synthesis Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Synthesis Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Synthesis Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Synthesis Sequencing errors Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Synthesis Nutrients and gene expression Copyright 2005 Wadsworth Group, a division of Thomson Learning

Roles of Proteins Building material –Growth –Maintenance Copyright 2005 Wadsworth Group, a division of Thomson Learning

Roles of Proteins Enzymes Copyright 2005 Wadsworth Group, a division of Thomson Learning

Roles of Proteins Hormones Copyright 2005 Wadsworth Group, a division of Thomson Learning

Roles of Proteins Regulation of fluid balance –Edema Acid-base regulation –Acidosis –Alkalosis Copyright 2005 Wadsworth Group, a division of Thomson Learning

Transport Proteins

Roles of Proteins Immunity –Antibodies –Antigens Copyright 2005 Wadsworth Group, a division of Thomson Learning

Roles of Proteins Source of energy Other roles Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Metabolism Protein turnover –Amino acid pool Nitrogen balance –Positive nitrogen balance –Negative nitrogen balance Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Metabolism Using amino acids to make proteins Using amino acids to make nonessential amino acids Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Metabolism Using amino acids to make other compounds –Neurotransmitters Using amino acids for energy and glucose Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Metabolism Deamination Using amino acids to make fat Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Quality High-quality proteins Digestibility –Animal vs. plant Amino acid composition –Limiting amino acid Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Quality Reference protein Complementary proteins Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein Quality PDCAAS –Protein digestibility- corrected amino acid score Copyright 2005 Wadsworth Group, a division of Thomson Learning

Food Labels Quantity of protein Daily Value –50 g protein 10% of a 2000 kcal diet Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein-Energy Malnutrition (PEM) Acute PEM Chronic PEM Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein-Energy Malnutrition (PEM) Marasmus Kwashiorkor Marasmus-kwashiorkor mix Copyright 2005 Wadsworth Group, a division of Thomson Learning

Protein-Energy Malnutrition (PEM) Infections –Dysentery Rehabilitation Copyright 2005 Wadsworth Group, a division of Thomson Learning

Health Effects Heart disease Cancer Adult bone loss –osteoporosis Copyright 2005 Wadsworth Group, a division of Thomson Learning

Health Effects Weight control Kidney disease Copyright 2005 Wadsworth Group, a division of Thomson Learning

Recommended Intakes RDA –0.8 g/kg/day –10% - 35% of energy intake Copyright 2005 Wadsworth Group, a division of Thomson Learning

Recommended Intakes Adequate intake Protein in abundance Copyright 2005 Wadsworth Group, a division of Thomson Learning

Supplements Protein supplements Amino acid supplements Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vegetarian Diets Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vegetarian Diets Health benefits Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vegetarian Diets Diet planning –Protein Lacto-ovo-vegetarians Meat replacements –Texturized vegetable protein Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vegetarian Diets Vitamins and minerals –Lactovegetarians –Vegans Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vegetarian Diets Omega-3 fatty acids Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vegetarian Diets Vegetarian diets through the life span –Pregnancy and lactation –Infancy –Childhood and adolescence Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vegetarian Diets Healthy food choices –Macrobiotic diets Copyright 2005 Wadsworth Group, a division of Thomson Learning