Photosynthesis, Respiration & Chemical Energy

Chemical Change (Reaction) Chemical reactions occur when old bonds break and new bonds form.

Chemical Change (Reaction) Chemical reactions involve two main kinds of changes that you can observe – –formation of new substances and –changes in energy (i.e. chemical  heat & light)

Snap H Pow H O O O O C H H Old Bonds Break New Bonds Form © Beadle, 2009

Endo/Exothermic Reactions Review (This will be related to Photosynthesis & Respiration) Exothermic: Respiration –Give off more energy during the reaction Endothermic: Photosynthesis –Take in or Absorb energy during the reaction. Energy © Beadle, 2009 Energy

Photosynthesis & Respiration + Endo/Exothermic Reactions Photosynthesis: (Like Endothermic Rxn’s) Plants take in Water (H 2 O) and Carbon Dioxide (CO 2 ). Plants take in Light energy from the sun and transform it into chemical energy by making sugar (C 6 H 12 O 6 ) and Oxygen (O 2 )(plant poo)! Respiration: (Like Exothermic Rxn’s) Animals breath in Oxygen (O 2 ) and eat the sugar (C 6 H 12 O 6 ) from plants. Animals then metabolize the sugar and oxygen and convert it back into Carbon Dioxide (CO 2 ) and Water (H 2 O) (Exhaled Animal poo). This process releases the stored chemical energy and converts it into mechanical and heat energy.

Photosynthesis & Respiration PlantsAnimals Light Sugar Oxygen High Chemical Energy Got it from light Water Carbon Dioxide Low Chemical Energy Some of the energy was used Mechanical Heat The chemicals go back and forth going from a low level of energy with Carbon Dioxide and Water to a high level of energy with Sugar and Oxygen. The sun gives the plant the necessary energy to transform lower levels of chemical energy into higher forms of chemical energy – energy that we animals can use. So photosynthesis is the process to convert light energy from the sun into chemical energy with sugar and oxygen – and respiration is the process of getting out the energy from the chemicals so that we can move and keep ourselves warm (mechanical and heat energy).

Respiration Process of unpacking the energy from the chemicals so that we animals can move. The chemicals received from the plants are packed with energy. It is like the batteries for our bodies which allows us to move and function. Without it, we would not be able to move, breath, think, live. Photosynthesis Process of using light to build powerful energy filled chemicals. This is like the factory which takes light energy from the sun and converts it into chemical energy. That chemical energy is bundled and stored in the chemicals – sugar and oxygen – which is then shipped to the critters in the rest of the ecosystem. PlantsAnimals Sugar & Oxygen (Chemical Energy) Light CO 2 & H 2 O How it all works Plants Endothermic (energy in) Animals Exothermic (energy out) CO 2 & H 2 O (Mechanical & Heat)

PlantsAnimals Sugar & Oxygen (Chemical Energy) Light CO 2 & H 2 O 1.Sun Light (bright sun hand gesture) Plants take in light energy from the sun plus the CO 2 & H 2 O from animals and… 2.Chem Food/Poo O 2 (puke hand gesture) converts it into volatile power packing chemical energy as sugar (food) & oxygen (poo). it is later sent to the animals. 3.Mechanical Energy Be Free in Me (Power Ranger) Animals take in the chemical energy as Sugar and Oxygen and unleash the energy as mechanical and heat energy – and convert the chemicals back into powerless carbon dioxide and water. These chemicals are then recycled back to the plants to collect energy. How it all works Plants Endothermic (energy in) Animals Exothermic (energy out) CO 2 & H 2 O (Mechanical & Heat)

PlantsAnimals Sugar & Oxygen (Chemical Energy) Light CO 2 & H 2 O Energy Sequence Plants Endothermic (energy in) Animals Exothermic (energy out) CO 2 & H 2 O (Mechanical & Heat) 1. Li ght Energy 2. Che mical Energy 3. M echanical & H eat Energy Li-Che-M High (Lick em) This slide gives you a mnemonic device to help you remember the energy sequence of how energy flows in an ecosystem. I want you to think of this Giraffe to remember the acronym.

Li ght Energy Che mical Energy M echanical & H eat Energy S ugar & O xygen Carbon Dioxide & Water PlantsAnimals Sugar & Oxygen (Chemical Energy) Light CO 2 & H 2 O Chemical Sequence Plants Endothermic (energy in) Animals Exothermic (energy out) CO 2 & H 2 O (Mechanical & Heat) SO CD Wet SOC? This slide gives you a mnemonic device to help you remember the chemical sequence of how the chemicals flows in an ecosystem. I want you to think of this sock to remember the acronym.

PlantsAnimals Sugar & Oxygen (Chemical Energy) Light CO 2 & H 2 O Plants Endothermic (energy in) Animals Exothermic (energy out) (Mechanical & Heat) Putting it all together When putting it all together, the sun continually sheds its light energy to the plants. The plants use that energy to produce food (chemical energy) and ships it to the animals where they unpack that energy and use it to move by converting it to mechanical and heat energy. The chemicals act like a conveyor belt which transports that energy from one living organism to another. Without those chemicals transporting the energy, you and I would not be alive simply because without it, energy would not be able to move from plants (producer) to animals (primary & secondary consumers).

Photosynthesis (Like an endothermic reaction) Photosynthesis takes place in the Plant Cells The Chloroplasts are where Light, water and Carbon Dioxide are processed into sugar (glucose) and oxygen Chloroplast

Chloroplasts Light Energy Sun Photosynthesis Endothermic Reaction Molecules go in and get zapped with energy. © Beadle, 2009 Carbon Dioxide molecules Water molecules 1. Sun

Chloroplasts Energy Stored Inside (Potential Chemical) Without Photosynthesis, nothing else could exist on this planet! YEAH! Go hug a tree and say “thanks!” Photosynthesis Endothermic reaction New molecules come out with stored energy Oxygen is a waste product that leaves the plant (plant poop!) Glucose is used by the plant for it’s food 2. Plant Poo

© Beadle, 2009 Respiration (Like an Exothermic Reaction) Animal Cell

Mitochondria (Human Cell) © Beadle, 2009 Respiration (Exothermic Reaction) The “Mitochondria” is where chemical energy is converted into mechanical energy Respiration takes place in the animal cells

3. Energy be free in me! Mitochondria (Human Cell) Respiration Similar to an Exothermic Reaction Molecules from plants go in… Our bodies are designed to unpack that energy stored in the sugar through a series of exothermic reactions. © Beadle, 2009 Oxygen Molecules Glucose Molecule Oxygen and Glucose molecules react with each other in the mitochondria and form new molecules our bodies use the released energy to do stuff

3. Energy be free in me! Unpack Stored Energy (Released Energy) Mitochondria (Human Cell) Note: The process by which sugar is broken down is a lot more complicated than a just a simple reduction of sugar – You’ll learn how in your Biology class in High School. © Beadle, 2009 Respiration Exothermic Reaction React and release the stored energy

3.Mechanical Energy be free in me! Energy Sequence Sun Unpack Stored Energy Released in Mechanical & Heat Energy Light Energy Mechanical & Heat Energy Chemical Energy 1.Light comes from the sun 2.Plants convert that energy into chemical energy via sugar 3.We eat the sugar and convert that energy into heat & mechanical energy 1. Sun Light 2.Chem Food/ Poo O 2

Now we send back our “waste products” to the plants! Every time we exhale, we send CO 2 and H 2 O back to plants Plants change the CO 2 and H 2 O into Glucose and O 2 that comes back to us

Why is this cycle so important? Remember the tragedy of the Strombolites… Strombolites are the earliest form of life we have ever found… the first ones, maybe as long as 4 BILLION years ago!!! Some still survive today as you can see in this picture: They are living bacteria that form rock like features when they grow together. It looks a bit like a coral reef They (like modern plants) did Photosynthesis But there were NO animals around yet…why is this a problem? A: There were no critters to turn the O 2 back into CO 2, and the Strombolites died off!!! Poor things… Moral: NOTHING CAN SURVIVE IN IT’S OWN WASTE!!!! Moral: NOTHING CAN SURVIVE IN IT’S OWN WASTE!!!! All the CO 2 in the atmosphere eventually became O 2. Which means what for our Strombolite friends…? 4 Billion years ago, the atmosphere was mostly CO 2, Which is GREAT for photosynthesis!!!

How long would you last…? Stuck in a sealed room with nothing but CO 2 ?

1) ____________ Energy comes from the sun Can Do: PHOTOSYNTHESIS 7) ______________energy converts to _______________ & ________ energy 3) Forms ___________________Energy 4) Makes:___________ and ___________ molecules Can Do: RESPIRATION 5) _____________ & _____________ molecules are sent to animals 6)Happens in: _______________ cells 2) Happens in: ______________ cells 8) Makes:________ ________and _______ “Photosynthesis” and “Respiration” Cycle See if you can fill in each blank in order starting at the sun! Sun (2 Chemicals) 9) ________ ________ & ____________ molecules are sent back to plants

1) ____________ Energy comes from the sun Can Do: PHOTOSYNTHESIS 7) ______________energy converts to _______________ & ________ energy 3) Forms ___________________Energy 4) Makes:___________ and ___________ molecules Can Do: RESPIRATION 5) _____________ & _____________ molecules are sent to animals 6)Happens in: _______________ cells 2) Happens in: ______________ cells 8) Makes:________ ________and _______ “Photosynthesis” and “Respiration” Cycle Light Plant Animal Chemical Mechanical Heat Carbon Dioxide SugarOxygen Water See if you can fill in each blank in order starting at the sun! Sun (2 Chemicals) 9) ________ ________ & ____________ molecules are sent back to plants Carbon Dioxide Water Sugar Oxygen