Protein Lecture 5 PDF

PROTEIN LECTURE 5 1  LEARNING OBJECTIVES ▪ Discuss the nature of proteins and amino acids. ▪ Discuss the roles of protein and amino acids in the body. ▪ Explain the processes of protein digestion and absorption of amino acids. ▪ Define the role of Proteins in Foods: Denaturation ▪...

PROTEIN LECTURE 5 1  LEARNING OBJECTIVES ▪ Discuss the nature of proteins and amino acids. ▪ Discuss the roles of protein and amino acids in the body. ▪ Explain the processes of protein digestion and absorption of amino acids. ▪ Define the role of Proteins in Foods: Denaturation ▪ List the types of Proteins in the food ▪ List the types of vegetarians ▪ List the factors that determine the daily protein needs of an individual. ▪ Discuss the potential health problems from an eating plan that is too low or too high in protein ▪ Design the treatment steps for protein deficiency diseases 2  ▪ The word protein comes from a Greek word meaning “of primary importance,”. INTRODUCTION ▪ Protein makes up approximately 20 percent of the human body and is present in every single cell. ▪ Proteins are called the workhorses of life as they provide the body with structure and perform a vast array of functions. 3 Proteins: large complex molecules composed of amino acids. WHAT IS Amino acids are commonly called protein’s building blocks. PROTEIN? Amino acids are composed of carbon, hydrogen, oxygen, and nitrogen and some amino acids also contain sulfur. 4 AMINO ACIDS ▪ All amino acids have the same simple chemical backbone consisting of a single carbon atom with both an amine group ( the nitrogen- containing part) and an acid group attached to it. ▪ Each amino acid also has a distinctive chemical side chain attached to the center carbon of the backbone. This side chain gives each amino acid its identity and chemical nature. ▪ The side chains make the amino acid differ in size, shape, and electrical charge. Some are negative, some are positive and some have no charge. 5 AMINO ACIDS ▪ All Amino acids are linked together with peptide bonds and any change in peptide sequence will cause a change in the structure and function ▪ There are 20 different amino acids used to make proteins: A- 11 non-essential amino acids produced by the body B- 9 essential amino acids you must have from food The body has at least 30,000 types of amino acids, each with a different job. 6 7  TYPES OF PROTEINS IN FOOD ▪ 1- Incomplete protein: does not contain all essential amino acids. ▪ Not sufficient for growth and health ▪ Considered a “low quality” protein ▪ Typically from plants ( soy beans, nuts) ▪ 2- Complete protein: contains sufficient amounts of all 9 essential amino acids. ▪ Considered a “high quality” protein ▪ Typically from animal products 8 TYPES OF PROTEINS IN FOOD 3- Complementary proteins: two protein sources that together supply all 9 essential amino acids. ▪ Examples: beans and rice, hummus. ▪ beans and sesame seeds, peanut butter and bread, tofu and broccoli with almonds 9 BEST SOURCES OF PROTEIN 10 FUNCTIONS OF PROTEINS IN THE BODY ▪ Maintain body tissues and wound healing ▪ Functions as enzymes and hormones ▪ Help maintain acid-base balance ( PH) ▪ Blood clotting ▪ Gene regulation ▪ Assist the immune system ▪ Balance the Fluid ▪ Make Antibodies to protect against disease ▪ Serve as a source of energy when necessary 11 PROTEIN DIGESTION AND ABSORPTION 12  THE ROLE OF PROTEINS IN FOODS: DENATURATION Denaturation refers to the physical changes that take place in a protein exposed to abnormal conditions in the environment. ▪ Also, Denaturing of proteins happens during food preparation (cooking, whipping, adding acids) or digestion (in the stomach with hydrochloric acid). ▪ Factors that cause denaturation: 1. Heat 2. Acids 3. Bases 4. Alcohol 5. high salt concentrations 13  TYPES OF VEGETARIANS 1. Lacto-ovo 4. Vegan. This type of 2. Lacto-vegetarian. 3. Ovo-vegetarian. vegetarian. This is vegetarian does not This type of This type of the most common eat dairy, eggs, or vegetarian eats dairy vegetarian eats eggs form. This type of any type of animal products but not but not dairy vegetarian eats eggs product or by- eggs. products. and dairy. product. 14 15  HOW MUCH PROTEIN SHOULD WE EAT? ▪ Recommended Dietary Allowance (RDA) is 0.8 grams of protein per kg body weight. ▪ Athletes may need slightly more protein 1.2- 1.7 g/kg ▪ 10% to 35% of calories should come from protein ▪ Quantity of protein intake depends on: ▪ Age Gender ▪ Health status Body Size ( larger people have a higher protein need) ▪ Activity level ▪ People who require more protein include: ▪ Children Pregnant or lactating women Elderly ▪ Teenager Vegetarians Ill and Injured People 16  ▪ Health Consequences of Too Much Protein in the Diet ▪ 1- High cholesterol and heart disease ▪ Diets high in protein from animal sources are associated with high cholesterol PROTEIN ▪ 2- Possible bone loss DEFICIENCY ▪ High protein diets MAY cause excess calcium excretion leading to bone loss AND EXCESS ▪ 3- Kidney disease ▪ High protein diets are associated with an increased risk of kidney disease, especially for people who may be susceptible to kidney disease ▪ 4- Colon cancer ▪ Red meat and processed meat are associated with a significant increase in colon cancer risk 17  ▪ Low protein intake has several health consequences, and a severe lack of protein in the diet eventually causes death. HEALTH ▪ Without adequate protein. ▪ Cells lining the GI tract are not sufficiently CONSEQUENCES replaced OF PROTEIN ▪ Digestive function is inhibited DEFICIENCY ▪ Absorption of food is reduced ▪ Intestinal bacteria get into the blood and cause septicemia ▪ Immune system cannot fight infection ▪ Slow growth in children 18 THERE ARE TWO COMMON FORMS OF PROTEIN DEFICIENCY: ▪ Marasmus ▪ Kwashiorkor 19  MARASMUS Disease resulting from severely inadequate intakes of protein, energy, and other nutrients. Marasmus symptoms include: – Severe wasting of muscle tissue – Stunted physical growth and many cannot stand without support – Stunted brain development – Anemia -Prone to dehydration, infections, and unnecessary blood clotting -Body temperature and blood pressure are low 20 KWASHIORKOR Disease resulting from an extremely diet high in grains and low protein intake due to diet or infection Kwashiorkor symptoms include: Some weight loss and muscle wasting swelling (edema) of the feet and abdomen poor skin health liver malfunction diarrhea, fatigue Retarded growth and development Hair is brittle and easy to pull out Prone to infection, rapid heart rate, excess fluid in lungs, pneumonia, septicemia, and water and electrolyte imbalances 21  TREATMENT Medical and nutritional treatment can dramatically reduce mortality rate Should be carefully and slowly implemented Step 1 – Address life-threatening factors Severe dehydration Fluid and nutrient imbalances Step 2 – Restore depleted tissue Provide nutritionally dense kilocalories and high-quality protein Step 3 – Transition to foods and introduce physical activity 22  Thank you Any questions? 23