6 61 Differentiate between essential amino acids and nonessential amino acids 62 List the functions of protein in the body 63 List the steps for protein digestion and absorption in the body ID: 914271
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Slide1
The Proteins and Amino Acids
6
Slide26.1 Differentiate
between essential amino acids and nonessential amino acids.
6.2 List the functions of protein in the body.6.3 List the steps for protein digestion and absorption in the body. 6.4 Explain the differences between high-quality and low-quality proteins, including food sources of each.
Chapter Objectives
Slide36.5 Calculate
the recommended protein intake for a given individual.
6.6 Develop a meal plan that incorporates protein-rich foods, including legumes.6.7 Identify the most common allergenic foods for children and adults.Chapter Objectives
Slide46.8 Describe
the nutritional challenges of a vegan diet and methods for developing a vegetarian eating pattern that delivers nutritional adequacy.
Chapter Objectives
Slide5Proteins consist of carbon, hydrogen, oxygen, and nitrogen
Amino acids are the building blocks
Amino acids: a compound with an amine group at one end and an acid group at the other endHave varying side chain structures Twenty different amino acids make up the proteins in living tissue6.1 What Proteins Are Made Of
Slide6Slide7Essential and nonessential amino acids
Essential amino acids must be supplied in the diet
Nonessential amino acids can be synthesized by the body6.1 What Proteins Are Made Of
Slide8Slide9Proteins as the source of life’s variety
Peptide bonds connect amino acids to form proteins
The amino acid chains form tangled coilsCharges on the amino acids cause different types of interactions between the amino acids and surrounding body fluidsProteins’ differing shapes result in differing functions6.1 What Proteins Are Made Of
Slide10Slide11Denaturation of
proteins
A change in the shape of a protein brought about by heat, alcohol, acids, bases, salts of heavy metals, or other agentsExamplesDigestive enzymes in the stomach break peptide bondsCooking an egg makes the egg firm and releases bound biotin and iron
6.1 What Proteins Are Made Of
Slide12Overview (see Table 6-2)
Growth and maintenance
Regulatory rolesEnzymesHormonesAntibodiesFluid balanceAcid-base balanceTransportationEnergy and glucose production6.2 The Functions of Body Proteins
Slide13Growth and maintenance
Amino acids are required to build new tissue
Amino acids must be constantly furnished by foodEnzymesAre proteinsAct as catalysts, i.e., biological spark plugsAre specific for their particular reactions6.2 The Functions of Body Proteins
Slide14Slide15HormonesAre not all made from proteins
Are messengers that cause specific reactions that restore normal conditions
AntibodiesForm in response to antigens (foreign proteins or other large molecules)Are unique for a particular antigenCreated by the body can be manufactured again later—the basis of immunity
6.2 The Functions of Body Proteins
Slide16Fluid balance: distribution of fluid among body compartments
Proteins help regulate
the quantity of fluids in the compartments of the bodyProteins attract water6.2 The Functions of Body Proteins
Slide17Slide18Acid-base balance
Is maintained by proteins acting as buffers
Is critical in keeping the blood’s normal pH within the range of 7.35 and 7.45Is handled by the charged side chains of amino acidsHydrogen ions are picked up or released as necessary6.2 The Functions of Body Proteins
Slide19Slide20Transport proteins
Move nutrients and other molecules into and out of cells
Regulate what substances the cell will take up or releaseExamplesThe “sodium-potassium pump”LipoproteinsProteins that carry fat-soluble vitamins, water-soluble vitamins, and minerals6.2 The Functions of Body Proteins
Slide21Protein as energy
Body’s number one priority is for energy
Protein is sacrificed to provide energy if requiredAmino acids can be converted to glucose during starvation conditionsResults in symptoms of protein deficiencyExcess amino acids lead to excreted amine groups along with glucose, glycogen, or fat production6.2 The Functions of Body Proteins
Slide22Food protein is broken down in the digestive system
Separated amino acids are delivered to the body cells
Cells assemble the amino acids building the particular proteins they needA missing essential amino acid halts protein synthesis6.3 How the Body Handles Protein
Slide23Slide24Protein in food supplies the amino acids
The body makes its own proteins
What are important characteristics of dietary protein?It should supply the nine essential amino acidsIt should furnish adequate amounts of amino acids to synthesize the nonessential amino acids6.4 Protein Quality of Foods
Slide25What are important characteristics of dietary protein?
It should be accompanied by adequate food
energy (preferably carbohydrates and fat) to support protein sparingHigh-quality proteins contain all the essential amino acids in the right proportion relative to the body’s needAnimal and soy proteins6.4 Protein Quality of Foods
Slide26Complementary proteins: two or
more food
proteins whose amino acid assortments complement each other The essential amino acids limited in or missing from each are supplied by the othersWhat determines protein quality?Digestibility of the proteinAmino acid composition
6.4 Protein Quality of Foods
Slide27Slide28Stated as percentage of total calories
10 to 35 percent of total caloric intake
Recommendation based on number of grams per dayProtein allowance for a healthy adult is 0.8 gram per kilogram (or 2.2 pounds) of desirable body weightLean body mass determines protein need for maintenance6.5 Recommended Protein Intakes
Slide29Consider both percentage and number of grams for adequate protein intake
Particularly when reducing energy intake substantially
6.5 Recommended Protein Intakes
Slide30Protein in the diet
More is not better when other nutrients are displaced
Balance food choices by selecting one-third of protein from animal sources and the rest from plants6.6 Choosing Protein-Rich Foods
Slide31Protein-rich food recommendations with consideration of solid fat content
Fat-free and low-fat dairy foods
Three servings each dayFish and shellfish—fresh, frozen, or canned in waterTwo meals per weekLean meats and poultry6.6 Choosing Protein-Rich Foods
Slide32Protein-rich food recommendations with consideration of solid fat content
Nuts, seeds, and nut butters
MyPlate: one tablespoon peanut butter or one-half ounce nuts or seeds equals one ounce of meatEggsOne egg equals one ounce of meatLegumesOne-fourth cup equals one ounce of meat
6.6 Choosing Protein-Rich Foods
Slide33Slide34Ways to increase your
intake of legumes (dried beans, peas, and lentils)
Add to entrees, side dishes, soups, and saladsExplore the many varieties of legumes used in cookingLearn more about legumeswww.americanbean.org/www.usdrybeans.comwww.pea-lentil.com/
The Savvy Diner: Eat More Beans
Slide35Reshaping your protein choices for health
Minimize the amount of meat; load up with vegetables and cooked beans
Go meatless one or more days per weekModify recipes using less meat and adding more vegetablesServe stir-fried vegetables over brown riceTry new lunch box itemsWater-packed tuna, low-fat yogurt, mashed dried beans with chopped onion, chili, tomato soup, etc.Eat Well Be Well:
Make
Over
Your Plate
Slide36Reshaping your protein choices for health
Dine out at ethnic restaurants with plant-based entrées
Eat seafood twice per weekConsume more legumes as well as red, orange, and dark green vegetables,Make whole grains, vegetables, and legumes the main course in mealsEat Well Be Well:Make Over Your Plate
Slide37Food allergy: an adverse reaction to an otherwise harmless substance
that involves
the body’s immune systemMain components of an allergic reactionFood allergens: food fragments that elicit the allergic reactionImmunoglobulin E (IgE): type of antibody that circulates in the bloodMast cells: specialized cells that store chemical substances, e.g., histamine6.7 Nutrition Action: Food Allergy—Nothing to Sneeze At
Slide38Histamine release produces various symptoms
Anaphylaxis is the most severe allergic reaction and potentially fatal
What foods cause most allergic reactions?Adults: shellfish, peanuts, tree nuts, fish, and eggChildren: peanuts, milk, and shellfish6.7 Nutrition Action: Food Allergy—Nothing to Sneeze At
Slide39Slide40Slide41Food allergy treatment
Offending food must be avoided
Medications treat the symptomsEpinephrine self-injecting syringes are used for accidental exposure6.7 Nutrition Action: Food Allergy—Nothing to Sneeze At
Slide42CharacteristicsHigher in fiber and certain vitamins and minerals
Lower in calories
Combined with positive lifestyle factorsContributes to beneficial health outcomes6.8 Spotlight: Vegetarian Eating Pattern
Slide43Slide44Slide45