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Cellular Respiration. Energy from Food. Cellular Respiration: the process of releasing energy stored in food for use in cells. Our goal is to find out the inputs and outputs of cellular respiration.
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Cellular Respiration Energy from Food
Cellular Respiration: the process of releasing energy stored in food for use in cells.
Our goal is to find out the inputs and outputs of cellular respiration
Please read pp. 288-289, “A Matter of Explosions” and answer the questions on your activity sheet.
Questions: • Where did the energy for the grain explosion come from? • How can energy be stored in grain? • What started the explosion that released the energy? • How do you explain the fact that you do not explode when you eat grain products such as cereal or bread?
So, what is our first IMPUT of cellular respiration: • FOOD! But not just food, GLUCOSE! • It’s chemical composition looks like this: C6H12O2 • Glucose is a sugar (and a carbohydrate). • Remember: Carbo=carbon, Hydrate=hydrogen+oxygen • Chemical energy is stored in food. Our digestive system is able to break down food into smaller parts like lipids, proteins, and carbohydrates that our cells can use to create energy.
Glycolysis • Glycolysis is the first step of cellular respiration. It releases some energy, but also creates the ingredients for the later steps to use. • Glycolysis means SUGAR SPLITTING • Glyco = sugar • -lysis = splitting
Candle Demonstration http://www.youtube.com/watch?v=x-stLxqPt6E • What made the candles go out? Why did the top candle go out first? • How can you explain the change in water level inside the beaker? • What does this tell you about the requirements for burning (releasing) energy? • Can you guess what our next input will be?
Oxygen is needed for cellular respiration • You can not light a fire without enough oxygen • Similarly, if you don’t have enough oxygen (O2) during cellular respiration than FERMENTATION occurs. • This creates Lactic Acid in your muscles • This is also the process that creates alcohol in beer and wine. • This process is called Anaerobic respiration. • When there is Oxygen present, we say it is AEROBIC RESPIRATION
Bromothymol Blue Demo • Why did the water turn clear? • What does this tell us about the gasses that come out when we breathe? • If you were to exercise heavily first and then exhale through the solution, would it change color faster or slower? Why? • Can you guess what our next output will be?
Carbon Dioxide • Carbon Dioxide is one byproduct of cellular respiration • It’s chemical composition looks like this: CO2 • CO2 is also emitted into the atmosphere by cars, boats, factories, and power plants when they burn fuel for energy (in MUCH bigger amounts).
Final reflection questions: • What form does the water produced by cellular respiration take? • Explain why when you exercise you breathe harder and sweat more (at least 3 sentences). • Draw your own diagram representing cellular respiration. Be as creative as you like.