How Do Organisms Get Energy From Food Exploring Creation with General Science Week 24 - Mod 12 Energy and Life – part 1 March 21, 2011 Sections: Introduction Life’s Energy Cycle How Do Organisms Get Energy From Food What Actually Gets Burned For Energy? For Next Time

Introduction We’ve learned about the skeleton, muscles, and skin. Now let’s learn about ENERGY and how the body uses it. Muscles – use energy to contract and relax Bones – use energy to grow, repair themselves, and make blood cells Skin – uses energy to make hair, skin cells, and nails. 2 2 2

Introduction Energy is used in all the functions of our life. Remember the 2nd Criterion for LIFE? 2nd Criterion: ALL life forms have a method by which they take energy from their surroundings and change it into energy that helps them live and grow. 3 3 3

Life’s Energy Cycle First, a few fundamental concepts… where does all of this energy come from? If following the 2nd Criterion, then we believe that living organisms TAKE or use energy from their surroundings. If they take it, where did it come from in the first place? Almost all energy comes from the . Most living organisms in Creation get their energy from this huge source. 4 4 4

Life’s Energy Cycle You think you get your energy from the food and drink that you consume. You do, but it’s a long chain of events that start with the sun. Remember the Biosphere experiment in Module 9? It was a closed container and after we started it and closed it up, did we add anything else? What was the only thing getting in there after that? __________. 5 5 5

Life’s Energy Cycle The PRODUCERS – organisms that make their own food. Convert energy from the sun & make food for themselves. P s is the process plants use to make their own food – g________. God designed the Producers to make much more food than they actually need. They store the food in a chemical form other than g________ (usually starch). 6 6 6

Life’s Energy Cycle Then animals eat the plants and utilize the stored energy INDIRECTLY from the sun through the plant starch. These animals are called CONSUMERS. They eat living producers (plants) and other consumers for food. Look at Figure 12.1, pg. 296 – notice the different types of Producers and Consumers. 7 7 7

Life’s Energy Cycle There’s a 3rd group… DECOMPOSERS: these were mentioned in Module 10. Although they could be called consumers since they don’t produce their own food, but because of their role, they are actually classified in a separate class. They recycle dead organisms back into the Earth; they act as fertilizer (vitamins for the plant kingdom). 8 8 8

Life’s Energy Cycle What about animals that scavenge and eat other dead animals, like vultures or hyenas? Are they decomposers? No, because their process doesn’t actually produce fertilizer or anything for the plants. So the 3 classifications are: Producers Consumers Decomposers 9 9 9

Life’s Energy Cycle Consumers can be broken down further into 3 categories… Herbivores – a consumer that ONLY eats producers. Carnivores – a consumer the ONLY eats other consumers. Omnivores – a consumer that eats BOTH producers & consumers. Cows: ____________ Lions: ____________ Humans: ____________ Vegans: __________ 10 10 10

How Do Organisms Get Energy From Food? On Your Owns 12.1 – there are 6 answers… and 12.2 – there are 3 answers. We’ve gone through how each category works, where they get their food from, and how the recyclers work, but HOW do organisms actually get energy from food? Not an easy question! We get energy from our food by “burning” it. This process is called a “combustion reaction”. 11 11 11

How Do Organisms Get Energy From Food? Combustion: the chemical process by which organisms get energy from food. This is what happens anytime an object is burned. Just like when we heat our homes by burning resources – usually natural gas. Organisms get energy by burning food. The following experiment will demonstrate some of the similarities between our bodies and our homes in terms of burning resources. 12 12 12

How Do Organisms Get Energy From Food? Experiment 12.1 – “What Combustion Needs” For our houses, we burn different things that are flammable. But the burning process that goes on in our bodies is different than that of a home furnace. Hypothesis? What do you think we will see? 13 13 13

How Do Organisms Get Energy From Food? Questions: How did the flame behave under different circumstances? What happened when the oxygen went away? What gas was created by our process? What did the new gas do in the bowl? What happened when we tried to re-light the candle? 14 14 14

How Do Organisms Get Energy From Food? Remember: Combustion requires oxygen. Can we have a fire in space? Conclusion: restate some of the things that you discovered – restate the principles of the experiment. Let’s look back at breathing for a moment. It’s a well known fact that we need oxygen to survive, but WHY? 15 15 15

How Do Organisms Get Energy From Food? We need oxygen to burn or combust our fuel (food). Without oxygen, all of our systems would shut down and we’d die. Ok, we now know that combustion needs 2 things… 1. something to burn (food, stuff, material) and 2. oxygen. 16 16 16

How Do Organisms Get Energy From Food? We also know that combustion produces energy, mostly in the form of heat and light. What else does combustion produce? ___________________ and ____________. Look at Experiment 12.2 – “The Products of Combustion”. We will do this experiment next week. “On Your Own” 12.3, 12.4, and 12.5 17 17 17

What Actually Gets Burned for Energy? We may eat all kinds of things, but our bodies are rather picky when it comes to what it will burn. Our bodies burn only carbohydrates, fats, and proteins. Our bodies even have a preference – 1st choice is carbs. If carbs aren't available, then our bodies go for fats. And if no fats, it goes for the proteins in our bodies. 18 18 18

What Actually Gets Burned for Energy? Together, carbs, fats, and proteins are called MACRONUTRIENTS because we need to eat lots of them. CARBS: simple carbs are MONOSACCHARIDES – also called “simple sugars”. Glucose, the chemical produced by plants, is an example of a simple sugar. Fructose is another example. It gives fruit its sweet flavor. 19 19 19

What Actually Gets Burned for Energy? DI-SACCHARIDE – when 2 or more Monosaccharides link together. The most famous one is table sugar – glucose and fructose linked together, also known as sucrose. POLY-SACCHARIDE – many Monosaccharides linked together. Starch is the most famous of these types. Look at Figure 12.2, pg. 304 20 20 20

What Actually Gets Burned for Energy? So, the body burns these carbs 1st. And the brain cells prefer carbs for energy – these cells can not burn fats or proteins. When your body runs low on carbs, it will burn fats & proteins in other parts of the body and save essential carb levels for the brain. However, the cells in your body can only burn Monosaccharide carbs. So it must break down the di- and poly- kind. 21 21 21

What Actually Gets Burned for Energy? FATS: 2nd macronutrient – two classifications – saturated and unsaturated. Saturated: solid at room temperature Unsaturated: liquid at room temperature Fried foods – hot fat, melted – saturated Veggie oil – liquid – unsaturated But FATS are essential for healthy living. It is insulation for our bodies & stores vitamins for later use. What vitamins? ___, ___, ___, ___ 22 22 22

What Actually Gets Burned for Energy? Your body can actually produce most of the fats it needs from carbs. If you eat more carbs than your body needs, it converts them to fat and stores them for future use. But there are some fats that your body can’t produce itself. These are called “Essential Fats”. These are typically found in veggie oil. So we must eat these kinds too, but you should eat everything in moderation. Review questions if time. 23 23 23

For Next Time Did you take the test for Mod. 11? Finish reading Mod. 12. Write up the “On Your Owns” so far…OR wait until the end of the module to turn them all in at once. Turn in write-up for Exp. 12.1 – “What Combustion Needs” Review if time allows… 24 24 24