Energy and Life Go to Section:

Living Things need energy to do work! 1. Growth 2. Reproduction 3. Movement 4. Response to stimuli 5. Active Transport 6. Homeostasis: maintain a stable & constant internal environment. Sunlight is the ultimate source of energy for life on Earth. Where does the Energy come from? Slide # 2

Energy Transformations: 1. Eat high energy organic molecules (food). 2. Break down or digest food. 3. Capture energy by breaking down food into a more usable form for the cell to use. 4. This usable form (ATP molecules) can pass energy around the cell. Slide # 5 Where do we get energy? Slide # 6

Where do we get energy? Slide # 3 1.Create a bond = store energy 2.Break a bond = release energy 3. Cells convert the storage bond energy to the phosphate bonds of ATP in the process of respiration

Why do cells use ATP molecules to transfer energy in the cell??? 1. ATP carries 7.3 kilocalories of energy, which provides just the right amount of energy for any chemical reaction in the cell, which uses only 3.5 to 7.3 kilocalories. 2. When transferring energy from ATP to an enzyme, some energy is lost as heat or light. 3. (7.3 kcal in ATP minus 3.5 kcal for a reaction leaves 3.8 kcal to be given off as heat or light.) Energy Currency Slide # 7

So what does ATP stand for? Adensosine triphosphate Slide # 8

Adenine Ribose 3 Phosphate groups Slide # 9 Go to Section: The Three Components of ATP

Go to Section: Energy Transformations Analogy Coal, Oil & Natural Gas Electricity Electric Power Plant Appliances Mitochondria Carbs, Lipids & Proteins ATP Cell Activities Enzyme Slide # 10

Energy is stored between the P bonds. Energy is stored between ATP’s 3 phosphate bonds. How does ATP store energy? Slide # 11 Ribos e Adenine P P P When a free phosphate group is attached to ADP, energy is stored in the bond to create ATP. Energy + + ADP P ATP + + Energy

Using ATP Energy For the cell to release and use the energy in ATP, the bond between the 2 nd and 3 rd phosphate groups must break; leaving ADP and a free phosphate group. Ribose Adenine P P P Energy Released ATP ADP P Slide # 15

ATP /ADP Cycle ATP ADP P P Energy Stored Energy Released to do work Bonds Formed to make ATP Bonds Broken ATP ADP A working muscle recycles over 10 million ATPs per second!!! Energy Released Energy Slide #

How ATP Causes Work to Take Place 1. The phosphate group that is removed becomes attached to a protein. 2. The protein changes shape and moves (allowing Na + into the cell) 3. The phosphate group leaves the protein & the protein returns to its original shape Slide # 17