Chapter 5 - All About Protien

Chp 5: Proteins Introductions Proteins are of "Prime importance" Versatile roles Facilitates chemical reactions Provides structure in all living tissues Chemist's View of Proteins Comprised of carbon, hydrogen, oxygen, and nitrogen atoms Amino = Nitrogen Containing The Structure of Proteins Amino acids: Protein building blocks, ~20 different amino acids in Proteins   Protein joining: Dipeptide, tripeptides, Polypeptides The Structure of Proteins Protein Shape Amino acid chains fold to complex shapes Protein Shapes Different shapes enable proteins to Perform different tasks in the body Non Essential & Essential Amino Acids Non Essential Amino Acids Those the body can make itself Essential Amino Acids must be obtained from foods Protein Turnover & Nitrogen Balance Protein turnover Continual process in which proteins are made and broken down Amino acids needed each day to support new growth and cell maintenance Nitrogen Balance intake = output Roles of Body Proteins Structural Comp. = muscle, bones, teeth, tendons, etc Enzymes Catalysts to essential life, Protein circle, Break food Proteins into amino acids Transporters Protein hemoglobin Chp 5: Cont.... Roles of Body Proteins Regulators of fluid and electrolytes balance maintain necessary amounts and types of fluid and minerals in each component proteins can help control fluid distribution this is because can't move freely across membranes are attracted to water cell membrane transport proteins transfer electrolytes and other substances in & out of cells to maintain balance   Regulators of acid-base balance maintain the balance between acid-base within body fluids Antibodies giant protein molecules produced when body detects antigens, specific to those antigens Hormones chemical messengers (some are proteins) Source of energy and glucose starvation results in wasting of lean tissue Protein Deficiency slow growth in children, impaired brain & kidney function, weakened immune defences, impaired absorption Malnutrition PEM = protein energy deficiency SAM = wasting thinness for height, rapid weight loss Chronic malnutrition = stunting low weight for age, restriction of growth Rehabilitation Protein Excess Heart disease animal derived protein high in fats can contribute to heart disease Kidney disease protein intake can speed up loss of kidney function Chp 5: Cont.... Protein Recommendations & Intakes Supplements Protein Supplements RDA (adults): 0.8 gram per kilogram (2.2 pounds) of healthy body weight Not needed by healthy food athletes use in weight loss un-Supported by Scientific Studies AMDR: 10% to 35% percent of kcalories Amino Acid Supplements Body absorbs AA. from whole Proteins best Typical U.S. intakes Men: 16% of kcalories Women, children, and some elderly: 13% to 15% of kcalories Protein Quality High quality proteins provide adequate amounts of all essential amino acids Digestibility measure of absorption Amino acid Composition limiting amino acid Essential for protein synthesis High quality Proteins Generally derived from animal foods Soy Proteins Complementary Proteins Two protein rich foods w/ differing amino acids combined to obtain all the essential amino acids in amounts to Support health Protein Sparing Carbohydrate and fat allow amino acids to be used to build body proteins if insufficient body will use protein to meet energy needs Protein on food labels Quantity required, % daily value reflects quality and quantity Nutrition in Practice Protein varied plant protein foods Appropriate Energy intake Vitamin D Adequate sunlight exposure, fortified foods Iron absorption increased by vitamin C Zinc legumes, enriched foods, whole grains Calcium dark leafy greens, Almonds Essential fatty acids flax seed, walnuts, soybeans, canola oil Vitamin B12 fortified foods/Supplements