Proteins The Function of Proteins are: Body and Cellular Support are composed of chains of amino acids held together by peptide bonds are polymers made from a set of 20 monomers or amino acids The Function of Proteins are: Body and Cellular Support collagen in your skin, hair, bones, and arteries provide strength CAM (cell adhesion molecule) proteins anchor cells together Organ and Body Movement actin and myosin filaments in muscle regulate muscle contraction Cellular Communication receptors, hormones, and MHC proteins allow cellular communicate Transportation of Nutrients hemoglobin carries oxygen via red blood cells throughout the body Regulation of Physiological Functions enzymes, hormones, and neurotransmitters regulate many activities

Protein Structure Chain of Amino Acids Held Together by Peptide Bonds Has 4 Levels of Structure Primary Secondary Tiertiary Quarternary

Essential Amino Acids

Peptide Bonds

Teeth

Muscle Tissue Skeletal Muscle Tissue Smooth Cardiac

Connective Tissue Cartilage Bone Adipose Tissue

Membrane Proteins Cell Proteins serve many different purposes

Enzymes Catalyze chemical reactions

Protein Sources FIGURE 6-17: TOP CONTRIBUTORS OF PROTEIN TO THE U.S. DIET. These foods supply about 70 percent of the protein in the U.S. diet. The remainder comes from foods contributing less than 2 percent of the total such as cold cuts; ready-to-eat cereal; white potatoes; sausage; flour and baking ingredients; ice cream, sherbet, and frozen yogurt; nuts and seeds; cooked rice and other grains; and canned tuna. aRounded values. Fig. 6-17, p. 204

Legumes Seed pods (peas), where nitrogen is stored FIGURE 6-18: A LEGUME. The legumes include such plants as the kidney bean, soybean, garden pea, lentil, black-eyed pea, and lima bean. Bacteria in the root nodules can “fix” nitrogen from the air, contributing it to the beans. Ultimately, thanks to these bacteria, the plant accumulates more nitrogen than it can get from the soil and also leaves more nitrogen in the soil than it takes out. The legumes are so efficient at trapping nitrogen that farmers often grow them in rotation with other crops to fertilize fields. Legumes are included with the meat group in Figure 6-16. Root nodules, which capture nitrogen

Legumes: Protein-rich and exceptionally nutritious. Fig. 6-18, p. 205

Meatless Protein? Fig. 6-13, p. 195 FIGURE 6-13: COMPLEMENTARY PROTEIN COMBINATIONS. Healthful foods like these contribute substantial protein (42 grams total) to this day’s meals without meat. Additional servings of nutritious foods, such as milk, bread, and eggs, can easily supply the remainder of the day’s need for protein (14 additional grams for men and 4 for women). Fig. 6-13, p. 195

Complementary Proteins FIGURE 6-14: PROTEINS THAT COMPLEMENT EACH OTHER WORK TOGETHER. In general, legumes provide plenty of the amino acids isoleucine (Ile) and lysine (Lys), but fall short in methionine (Met) and tryptophan (Trp). Grains have the opposite strengths and weaknesses, making them a perfect match for legumes. Fig. 6-14, p. 196

Meat, Poultry, Fish, Dried Peas and Beans, and Nuts Make lean or low-fat choices