Energy in Living Things

And the molecule ATP

What is Energy?

Very difficult to define as a whole, but we Very difficult to define as a whole, but we know it’s various formsknow it’s various forms

General Forms of Energy

Potential Kinetic

Living Organisms Require Energy

To build molecules/growTo build molecules/grow

To moveTo move

To survive (fight diseases, To survive (fight diseases, avoid predators, find food avoid predators, find food etc.)etc.)

To reproduceTo reproduce

Energy is neither created Energy is neither created nor destroyednor destroyed

Not used up- only converted Not used up- only converted from one form to anotherfrom one form to another

Where does all the energy Where does all the energy go?go?

HeatHeat

1st Law of Thermodynamics

The Basics of Metabolism

Chemical energy (food) inChemical energy (food) in

Food converted into a more Food converted into a more readily usable formreadily usable form

Energy lost as heat when work Energy lost as heat when work is doneis done

How Does Energy Get Into Food?Photosynthesis! Photosynthesis! (Light energy (Light energy Chemical energy)Chemical energy)

Animals eat plantsAnimals eat plants

How Do We Convert It?

Cellular Cellular Respiration!Respiration!

Food Food ATP ATP

Why convert to ATP? Why not just

transfer the energy from food

directly?A.) Basically – food molecules have too A.) Basically – food molecules have too much energy. If cells broke down a much energy. If cells broke down a food molecule directly A LOT of energy food molecule directly A LOT of energy would just go to waste. would just go to waste.

B.) A visual model: B.) A visual model: http://www.youtube.com/watch?v=nN8xD_bv2aQ

ATP (Adenosine TriPhosphate)

Stores energyStores energy

When split into When split into ADP and P ADP and P releases energyreleases energy

Transfers energy Transfers energy to where it is to where it is neededneeded

Exothermic Reaction

Energy is Energy is released released WHEN NEW WHEN NEW BONDS BONDS FORM!FORM!

ATP Does Work

Provide energy for Provide energy for reactionsreactions

Can change shape of Can change shape of proteinsproteins

Flex muscles/movementFlex muscles/movement

Pump moleculesPump molecules

AdenosineDiPhosphateAdenosineTriPhosphate

From light in light reactionsFrom food in cellular respirationTo flex muscle, start reaction or do

anything really

How important is ATP?

1 billion molecules per cell, used and 1 billion molecules per cell, used and remade every couple minutesremade every couple minutes

10102424 in one human in one human

Average ATP molecule is made and Average ATP molecule is made and broken down about 3 times per minutebroken down about 3 times per minute