Section 8.1 Carbohydrates, Fats, and Proteins Carbohydrates, Fats, and Proteins Objectives Name the three classes of nutrients that supply your body with energy. Explain how the body obtains energy from foods. Describe the roles that carbohydrates, fats, and proteins play in your body. Slide 1 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Video Introductorio https://www.youtube.com/watch?v=cptGzi0wLiE Slide 2 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Nutrition The sum of the processes by which humans, animals, and plants consume and use food is nutrition. Slide 3 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Nutrients Food is eaten and digested in the body to allow the absorption of energy and nutrients. There are two different types of nutrients: macronutrients; micronutrients. There are three macronutrients that are essential for health. These are: • carbohydrate; • protein; • fat. Macronutrients are measured in grams (g). Slide 4 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Foods Supply Nutrients • Food supplies your body with nutrients, substances in food that helps with body processes (regulate bodily functions, promote growth, repair body tissues, and obtain energy). • There are six classes of nutrients: carbohydrates, fats, proteins, vitamins, minerals, and water. • Carbohydrates, fats, and proteins can all be used by the body as sources of energy. Slide 5 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Foods Supply Energy • The foods you eat are your body’s energy source. • You need energy to maintain your body temperature, keep your heart beating, and enable you to understand what you read. Slide 6 of 35 Section 8.1 Carbohydrates, Fats, and Proteins What are Calories? • The amount of energy released when nutrients are broken down is measured in units called calories. • The more calories a food has, the more energy it contains. Slide 7 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Slide 8 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Slide 9 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Carbohydrates • Carbohydrates are nutrients made of carbon, hydrogen, and oxygen. • Carbohydrates supply energy for your body’s functions. • A nutrient that is the main source of energy for the body is a carbohydrate. Slide 10 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Carbohydrate The two types of carbohydrate that provide dietary energy are starch and sugars. Dietary fibre is also a type of carbohydrate which is not digested to provide energy. Starchy carbohydrate is an important source of energy. 1 gram of carbohydrate provides 4kcal (17kJ). Section 8.1 Carbohydrates, Fats, and Proteins Structure of carbohydrate All types of carbohydrate are compounds of carbon, hydrogen and oxygen. They can be classified in many different ways. One common way is according to their structure. Sugars Sugars come from a variety of foods. Some are within the cellular structure of the food, e.g. in fruit or vegetables. Other sugars are not bound into the cellular structure of the food, e.g. in milk or honey. Section 8.1 Carbohydrates, Fats, and Proteins Free sugars Free sugars include all sugars added to foods plus sugars naturally present in honey, syrups and unsweetened fruit juice. The term does not include lactose (the sugar in milk) when naturally present in milk and dairy products and the sugars contained within the cellular structure of foods (e.g. fruit and vegetables). The recommendations state that less than 5% of total energy intake should come from free sugars. For more information about free sugars, go to: www.nutrition.org.uk Section 8.1 Carbohydrates, Fats, and Proteins Starchy carbohydrate Starch is found in a variety of foods. It is made up of many sugar molecules. Can you give some examples of sources of starch in the diet? • • • • Potatoes Bread Rice Pasta Cereal and cereal products are the main source of carbohydrate for adults in the UK. Section 8.1 Carbohydrates, Fats, and Proteins Simple Carbohydrates Simple carbohydrates are sugars that enter the bloodstream rapidly and provide quick energy. • Simple carbs provide calories but few vitamins and minerals. Complex Carbohydrates Complex carbohydrates are made up of sugars that are linked together chemically to form long chains. •Starch – a food substance that is made and stored in most plants • Provide long-lasting energy Slide 15 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Carbohydrates can be… Simple Carbs Complex Carbs - Fruits - Honey - Milk - Sugars added to cookies, candies, soft drinks -Grains (bread & pasta) -Vegetables (potatoes & beans) -Rice -Cereals -Wheat -Tortillas -Whole-wheat rolls Slide 16 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Fiber • Fiber is a type of complex carbohydrate that is found in plants. • A high-fiber diet • helps prevent constipation • may reduce the risk of colon cancer • may help prevent heart disease • The part of grains and plant foods that cannot be digested is called fiber. Slide 17 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Your Body’s Energy Reserves • At a meal, you usually eat more carbohydrates than your body can immediately use. • The extra glucose is converted into a type of starch called glycogen. • Glycogen is stored in the muscles and when you need energy, it is converted to glucose. • If you eat so many carbohydrates that the body’s glycogen stores are full, then the excess carbohydrates are stored as fat instead. Slide 18 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Activity 1. DRAW UP A COMPARATIVE TABLE OF THE CLASSIFICATION OF CARBOHYDRATES Slide 19 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Fats • Fats are made of carbon, hydrogen, and oxygen. • Fats supply your body with energy, form your cells, maintain body temperature, and protect your nerves. • A nutrient that provides energy and helps the body store and use vitamins is a fat. Slide 20 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Fat Fat provides fat-soluble vitamins A, D, E and K, and is necessary for their absorption. It is also important for essential fatty acids the body cannot make. Fat provides a concentrated source of energy: 1 gram of fat provides 9 kcal (37 kJ) of energy. Foods that contain a lot of fat provide a lot of energy. Section 8.1 Carbohydrates, Fats, and Proteins Structure of fat Fat is made up of different types of fatty acids and glycerol. The structure of the fatty acids determines: their effect on our health; their characteristics, e.g. melting point. Depending on their chemical structure, fatty acids are usually classified as: saturated; monounsaturated; polyunsaturated. Section 8.1 Carbohydrates, Fats, and Proteins Unsaturated Fats • Unsaturated Fats have at least one unsaturated bond in a place where hydrogen can be added to the molecule. • Unsaturated fats are usually liquid at room temperature. • Unsaturated fats are classified as either monounsaturated fats or polyunsaturated fats. Slide 23 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Saturated Fats • Fats that have all the hydrogen the carbon atoms can hold are called saturated fats. • Saturated fats are usually solid at room temperature. • Too much saturated fat in your diet can lead to heart disease. Slide 24 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Daily Fat Intake Nutritionists recommend that 20-35% of your calories come from fat, primarily unsaturated fat. Slide 25 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Cholesterol • Cholesterol is a waxy, fatlike substance that is found only in animal products. • Your body needs a certain amount of cholesterol to make cell membranes and nerve tissue, certain hormones, and substances that aid in the digestion of fat. Slide 26 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Trans Fats • Trans fats are made when manufacturers add hydrogen to the fat molecules in vegetable oils. • Trans fats are found in margarine, chips, and commercially baked goods. • Trans fat seems to have many of the negatives of saturated fat. Slide 27 of 35 Section 8.1 Carbohydrates, Fats, and Proteins ACTIVITY 2 DRAW UP A COMPARATIVE TABLE OF THE CLASSIFICATION OF FATS Slide 28 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Proteins • Nutrients that contain nitrogen as well as carbon, hydrogen, and oxygen are called proteins. • Proteins can serve as a source of energy. • A nutrient that is needed for growth, and to build and repair body tissues is a protein. Slide 29 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Proteins Protein functions include: 1. enzyme catalysts 2. defense 3. transport 4. support 5. motion 6. regulation 7. storage Section 8.1 Carbohydrates, Fats, and Proteins Protein Protein is essential for growth and repair and keeping cells healthy. Protein also provides energy: 1 gram of protein provides 4 kcal (17 kJ). Section 8.1 Carbohydrates, Fats, and Proteins Structure of protein Protein is made up of building blocks called amino acids. Different foods contain different amounts and different combinations of amino acids. Protein from animal sources (e.g. meat, fish, eggs and dairy products) contains the full range of essential amino acids needed by the body. Protein from plant sources (e.g. pulses and cereals) typically contain fewer essential amino acids. Section 8.1 Carbohydrates, Fats, and Proteins Proteins Proteins are polymers of amino acids. Amino acids -20 different amino acids -joined by dehydration synthesis -peptide bonds form between adjacent amino acids Section 8.1 Carbohydrates, Fats, and Proteins Proteins Section 8.1 Carbohydrates, Fats, and Proteins Proteins Amino acid structure -central carbon atom surrounded by -amino group -carboxyl group -single hydrogen -variable R group Section 8.1 Carbohydrates, Fats, and Proteins Proteins Section 8.1 Carbohydrates, Fats, and Proteins Proteins Section 8.1 Carbohydrates, Fats, and Proteins Sources of protein Animal: • meat; • fish; • eggs; • milk; • cheese. Plant: • nuts; • seeds; • pulses, e.g. beans, lentils; • mycoprotein; • soya products. Section 8.1 Carbohydrates, Fats, and Proteins Slide 39 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Slide 40 of 35 •4 Section 8.1 Carbohydrates, Fats, and Proteins 1 Proteins Denaturation is a change in the shape of a protein, usually causing loss of function. -may involve complete unfolding -caused by changes in the protein’s environment -pH -temperature -salt concentration Section 8.1 Carbohydrates, Fats, and Proteins Amino Acids • Proteins are long chains of smaller “links” that are bound together chemically. • These smaller substances are known as amino acids. • The building blocks that make up proteins are amino acids. Slide 42 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Essential Amino Acids The nine amino acids that the body cannot manufacture are called essential amino acids. Slide 43 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Complete and Incomplete Proteins • Protein from animal sources is complete protein. • It contains all nine essential amino acids. • Most protein from plant sources is incomplete protein. • It lacks one or more of the essential amino acids. Slide 44 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Daily Protein Intake Nutritionists recommend that 10-35% percent of your calories come from proteins. Proteins for Vegetarians People who don’t eat meat can combine two or more plant protein sources that, taken together, provide all the essential amino acids. Slide 45 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Activity 3. DRAW UP A COMPARATIVE TABLE OF THE CLASSIFICATION OF PROTEINS Slide 46 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Vocabulary nutrient A substance in foods that the body needs to regulate bodily functions, promote growth, repair body tissues, and obtain energy. metabolism The chemical process by which the body breaks down food to release energy. calorie Unit for the amount of energy released when nutrients are broken down. carbohydrate A nutrient made of carbon, hydrogen, and oxygen and that supplies energy. fiber A way of dealing with an uncomfortable or unbearable feeling or situation. Slide 47 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Vocabulary fat unsaturated fat saturated fat cholesterol A nutrient made of carbon, hydrogen, and oxygen; supplies energy, forms cells, maintains body temperature, and protects nerves. A fat with at least one unsaturated bond in a place where hydrogen can be added to the molecule. A fat that has all the hydrogen the carbon atoms can hold. A fat that has all the hydrogen the carbon atoms can hold. A waxy, fatlike substance that is found only in animal products. Slide 48 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Vocabulary trans fat The type of fat produced when manufacturers add hydrogen to the fat molecules in vegetable oils. protein A nutrient that contains nitrogen as well as carbon, hydrogen, and oxygen; needed for the growth and repair of body tissues. amino acid Small units that are bound together chemically to form proteins. Slide 49 of 35 Section 8.1 Carbohydrates, Fats, and Proteins Questions 1) 2) 3) 4) 5) 6) 7) Which 3 classes of nutrients supply the body with energy? Define the term metabolism. How is metabolism related to the nutrients in food? What roles do the following nutrients play in the body? A. carbohydrates B. fats C. proteins What is cholesterol? How does diet affect cholesterol levels in the blood? Name a circumstance during which you might use your body’s stores of glycogen. How do saturated fats differ from unsaturated fats? Name 2 sources of each type of fat. Suppose that you ate 2,500 calories/day. Of those calories, 1,200 calories were from carbs, 875 from fats, and the rest from protein. What % of your total day’s calories came from carbs, from fats, and from protein? Slide 50 of 35