Transcript Energy:
How the Body Obtains and Uses Energy Copyright 2010. PEER.tamu.edu Discuss: Are you an energetic person? When do you have the most energy? What do you do when you need to get more energy? Energy Energy is all around you! You can hear energy as sound. You can see energy as light. And you can feel it as wind. When do you use energy? You use energy when you: hit a softball. lift your book bag. grow. study. do any activity. Why is energy important to our bodies? Living organisms need energy for their bodies’ daily activities and processes. Try to Recall the Six Forms of Energy The six main forms of energy are: Heat or Thermal Chemical Electromagnetic Nuclear Mechanical Electrical Our bodies use Chemical Energy States of Energy There are two states in which energy can exist: Potential Energy Stored energy. Energy that could be used. Kinetic Energy Energy of Action or Motion. Energy that is being used. Energy Conversions or Transformations Energy can be changed from one form or state into another. Changes in the forms or states of energy are called energy conversions or transformations. An Essential Energy Conversion • Our body converts starches, sugars, fats and even proteins (chemical energy) that we eat into energy for our bodies’ daily functions (mechanical and heat or thermal energy). Chemical Energy Mechanical and Heat Energy How the Body Obtains Energy First, you consume energy in the form of foods. Foods are made of organic molecules. The organic compounds in foods that can be used for energy are: Carbohydrates Fats Proteins Molecules are held together by an energy force. Breaking the bonds between atoms in the molecules releases that energy. A Glucose (sugar) Molecule C6H12O6 Whether or not that bond energy does anything depends on whether it can be captured and "put to work." The body's job is to break food down so that cells can break down some of the chemical bonds. Then that energy can be used to do things. Any left-over energy escapes as heat. Bond between atoms in the molecule. During the digestion process, how does the body breaks down foods into smaller organic compounds? The teeth first break down the food physically into smaller pieces. The movement of the stomach and intestines also help physically break the food. Proteins are broken down chemically by pepsin in the stomach into amino acids. Carbohydrates are broken down chemically into sugars (monosaccharides) by enzymes found in saliva in the mouth and by enzymes in the small intestine. Fats are broken down into fatty acids by bile from the liver in the small intestines. •These smaller molecules are transported into body cells and then go through several chemical processes that break the molecular bonds to produce ATP, a primary storage form and source of energy in the body. •These chemical processes occur in the cytoplasm and mitochondria in the cells. Mitochondria Cytoplasm For more on energy use in the body please click here Mitochondria, plural for mitochondrion, are the organelles that cells use as their energy factories. Think of them as the cell's way of recharging its battery. An artist’s representation of a mitochondrion An electron micrograph of a mitochondrion A mitochondrion is an oval bag that is filled with membranes. Mitochondria are so small that you can only see them with the high-power magnification of an electron micrograph. Stop and Think: What is an energy conversion or transformation? What energy conversion is essential for the human body? Summarize how humans get their energy from food. Be sure to include the structures in the body that are responsible for this process. Calories Calories are a unit of measurement of food energy. They measure the amount of potential heat energy contained in the chemical bonds of a food. People need a certain amount of calories per day. For the average teenage girl, the recommended daily allowance is 2200 calories. The average teenage boy needs 2500-3000 calories. Calories add up fast! A large cheeseburger, fries, and a soda can add up to more than 1,390 calories. That’s more than half of the calories that most teens need in one day! This is not a good deal for your body because this meal does not contain many of the other nutrients your body needs besides calories. Our Energy Use Must be Balanced! The amount of energy that comes into our body should be equal to the amount of energy that we use. If it is not, we STORE the extra energy that is not used. The main way the body stores excesss energy is in the form of fat. Did I eat ALL of that? Energy Imbalance Causes Problems Obesity BMI Calculator A person has traditionally been considered to be obese if they are more than 20 percent over their ideal weight. That ideal weight must take into account the person's height, age, sex, and build. If their Body Mass Index (BMI) is between 25 and 29.9 a person is considered overweight. If their BMI is 30 or over the person is considered obese. Obesity is a problem in people and pets! An estimated 51.5% of dogs and cats in the United States are overweight or obese. Childhood obesity has more than tripled in the past 30 years. The prevalence of obesity among adolescents aged 12 to 19 years increased from 5.0% to 18.1%. Common Health Risks of Obesity Osteoarthritis Type 2 Diabetes Respiratory disorders Hypertension (high blood pressure) Heart Disease Many Forms of Cancer How to keep Energy Balanced: The best way to balance your energy is to find out how much energy is used by the body each day and….. Energy Used in a Day Eat only enough calories to equal that amount of energy. Energy Consumed in a Day Special Considerations for Teens Teens have a little higher energy requirement than adults. Can you guess why? The answer is that they are growing! Growth requires energy and healthy nutrients from foods. As a teen, you must choose wisely so you can reach your potential! Can you recall? What are calories? How is extra energy stored in our bodies? What are some risks associated with obesity? What is meant by “energy balance” in the body?