Human Nutrition What is an organic molecule? What is the difference between “whole” and “highly processed” foods? activity: Write which food you think matches the column and nutrition information (A-F). Class correct Column Pizza 3” of tuna sub Medium fries Cheese quesadilla Plain hamburger Chicken tenders There are an overwhelming number of different diets, “quick fixes”, supplements, and weight loss aids out there. We will learn about human nutrition and let you decide whether or not you think the claims are backed by scientific evidence, or if they are a healthy way to lose weight. Whether food is whole or ultra-processed, it consists mostly of macronutrients. These are ________________ that we need to consume in significant amounts. 1. Carbohydrates 2. Lipids 3. Proteins Where do most of these molecules come from? Define monomer: Define polymer: Summary chart of important monomers and polymers Monomer Polymer 1 Simple sugars (monosaccharides) Carbohydrates (polysaccharides) Fatty acids Fats (a type of lipid) Amino acids Proteins The Basics Polymers are formed by chemically bonding smaller subunits, called monomers, together. Food typically enters the body in polymer form and must be broken down into monomers. • In animals, this occurs in the digestive system and requires enzymes. This process uses water to break the bonds that holds the monomers together. • This process continues until the polymer is completely broken down. The monomers then enter the bloodstream where they are transported to individual cells. Now that the food has been broken down into monomers, it can be rebuilt into the specific polymers needed by our cells. Why do we eat? Food = _______________! Energy is measured in kilocalories. Remember, 1 kilocalorie is the same as 1 Calorie, which is what you are probably more used to seeing on your nutrition labels. Your body burns calories even when you aren’t moving. What are some processes that might contribute to this? Calorie basics: Calories taken in through food equal to energy expended (at rest and active): More calories in than energy expended: Less calories in than energy expended: metabolism is the sum of all the chemical reactions going on inside your body. This is also known as your basal metabolism, which relates to the number of calories your body needs to carry out basic cellular functions. What are some factors that can affect your individual basal metabolism? Body size and composition Gender Age Three factors contribute to the calories you burn: 1.Basal metabolism 2.Food processing 3.Physical activity Energy is not the only requirement supplied by food. If it were, we could live on sugar—but even hummingbirds supplement their nectar consumption with insects, which contain protein, fat, vitamins, and minerals. 2 In addition to energy, food provides cells with the organic building blocks they need to make the thousands of complex molecules required for maintenance, growth, and reproduction, and the vitamins and minerals that facilitate these processes. There are metabolic disorders than can affect your ability to lose weight, along with other more serious complications. 1. Carbohydrates • Made of C, H, and O • Primary fuel source and compose certain cell structures. • The recommendation is that about 45-65% of your daily calories come from carbohydrates. However, this is variable from person to person. • One gram of carbohydrates contains 4 calories. Monosaccharides/Simple Sugars The primary function of simple sugars in cells is energy An example of a monosaccharide is the sugar glucose. Another example is fructose. You may have heard of high fructose corn syrup. What is this and why do we hear about it in the news? refined corn turned into sugar When cells have extra glucose, they store it in polymer form to be used later; it can also be converted to fat. Disaccharides If two simple sugars are bonded together, the result is a disaccharide. Examples of important disaccharides are How do artificial sweeteners relate? Polysaccharides These may be anywhere from 100 to 1000s of simple sugars bonded together. The difference between them is how the simple sugars are bonded together. • Starch-made by plants, animals ingest and break down • Glycogen-made by animals, animals breakdown as needed • Cellulose 3 • Chitin 2. Lipids • There are many different types of lipids and they all have unique chemical structures. • Like carbohydrates, all lipids contain C, H, and O. • Lipids are ____________________ in water. Fats/Triglycerides Their primary function is The recommendation is that about ________% or less of your daily calories come from fats. However, this is variable from person to person. One gram of fat contains _______ calories. The general structure of a fat includes Saturated fatty acids The term saturated fat refers to fatty acids whose tails have no double bonds. This means that the carbon atoms have bonded to or “saturated” with the maximum number of H atoms possible. • Some properties of saturated fatty acids are Unsaturated fatty acids An unsaturated fatty acid contains one or more double bonds in its tails. This means that less than the maximum number of H atoms is present. • Some properties of unsaturated fatty acids are • The difference between a monounsaturated and a polyunsaturated fat is Trans fatty acids • Produced via hydrogenation which is a process that • What health risks are associated with trans fats? Fat substitutes • What are these? What happened to them? 4 Cholesterol • A lipid obtained in the diet and produced by the liver. Most of your circulating cholesterol is formed in the liver from saturated fats, ingested in our diet. • Some cholesterol from the diet will be used to make certain essential cell structures and steroid hormones. Examples include • Cholesterol is packaged by your body in one of two manners ▪ HDL (high density lipoprotein): When cholesterol is packaged in HDLs, it will be ▪ • LDL (low density lipoprotein): When cholesterol is packaged in LDLs, it will be LDL levels are decreased and HDL levels are increased by A bit about heart disease, saturated fatty acids, trans fatty acids, and cholesterol Saturated fatty acids, trans fatty acids, and cholesterol can increase a person’s risk of developing atherosclerosis and heart disease because: • What lifestyle changes can reduce the chances of this happening? • How does a person know if they have this? • Why would a person take a statin drug? • How can it be corrected if it already happened? 3. Proteins • The monomers that bond together to form proteins are amino acids. 5 • • • There are 20 different amino acid monomers used to make proteins and many of them are obtained in the diet, called _________________________, while some amino acids can be made by cells. The recommendation is that about ________% of your daily calories come from proteins. However, this is variable from person to person. Proteins are the most diverse type of polymer due to the ability to arrange amino acids in different sequences to generate unique proteins. Give some examples of various types of proteins: • Explain the difference between a complete and incomplete protein. • Are you or any of your friends/family members vegetarians or vegans? Discuss how they get complete protein in their diets. • What happens to proteins in your body once ingested? • Proteins fold and twist into 3D shapes. The shape of proteins is critical to their proper functioning. o • What happens when a protein is denatured? Why do you get a fever, and could you die if it gets too high? Nutrition Label Notes: 6 Whole foods don’t have nutrition labels. However, you can access this information on many websites. The U.S. Department of Agriculture (USDA) has a consumer education site for food and nutrition called choosemyplate.gov 7
