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PROTEINS. Chapter 7. Amine group Carboxylic Acid group R group. Building Blocks of Proteins?. R O NH2 C C OH H. Examples of Amino Acids. Essential versus Non-essential. Limiting Amino Acid. CCCCC
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PROTEINS Chapter 7
Amine group Carboxylic Acid group R group Building Blocks of Proteins? R O NH2 C C OH H
Limiting Amino Acid CCCCC AAAAAAAA CAR CAR CAR RRRRRR CAR CAR R A A A C is the limiting amino acid in this example
Complementary Protein Food 1 Food 2 CC CCCC AAAA AA CAR CAR CAR RRR RRR CAR CAR CAR
Dietary Aspects • PKU = Phenylketonuria • Vegetarian Diets
Protein Synthesis • Step 1: • Transcription • Step 2: • Processing • Step 3: • Translation
Transcription • Formation of RNA from DNA template A C T G A T U G A C U A DNA= RNA= CODON#1 CODON #2
Condensation Synthesis • Peptide bond • Dipeptide • Tripeptide • Oligopeptide • Polypeptide
Functions of Proteins • Supplies nitrogen in a useable form • Structural components • Blood clotting • Maintain fluid and acid/base balance • Immune function
Functions of Proteins • Hormones and enzymes • Insulin and Thyroxine • Pepsin, Trypsin • Visual processes • Formation of glucose (Gluconeogenesis) • Energy Source (4 kcal/energy)
RDA for Protein • Promotes equilibrium • 0.8 gm of protein / kg of healthy body weight 154 lb. = 70 kg 2.2 kg/lb. 70 kg x 0.8 g protein = 56 g protein kg healthy body wt
Proteins in Foods • Americans tend to eat more animal protein than plant protein (70%) • There are many benefits to eating more plant proteins:
Plant Protein • No cholesterol • Low in saturated fat • High in (soluble) dietary fiber and phytochemicals HOWEVER: • Somewhat less efficient (than animal protein) • Lacking in one or more essential amino acid
Protein-Energy Malnutrition • Types of PEM: • Kwashiorkor • Marasmus • Causes: • Famine • Anorexia • Intestinal disorders
Kwashiorkor • Low protein density diet • Energy needs are marginally met • Subcutaneous fat is present • Poor growth, edema, weakness, apathy, diarrhea, listlessness
Marasmus • Starving to death • “skin and bones” appearance • Insufficient protein, energy, nutrients • Little or no subcutaneous fat • Reduce brain growth
Nutrition Perspective • Vegan - primarily eats only plant foods • Fruitarian - primarily eats fruits, honey, and vegetable oils • Lactovegetarian - consumes plant products and dairy products • Lactoovovegetarian - consumes plant products, dairy products, and eggs