Photosynthesis & Cell Respiration How do we get our energy?

Never Fear… SUPERPlant is here!!! Energy Oh No!! We’re DOOMED!! There is only 1 source of energy for all of the living things on this planet…the SUN! Unfortunately as humans we CANNOT harvest this energy directly! Luckily for us PLANTS do that job for us!

Photosynthesis Plants absorb the light from the Sun and turn it into SUGAR and OXYGEN for us This process is called PHOTOSYNTHESIS! This happens in the CHLOROPLAST (organelle) in the plant cell. Do animal cells have chloroplasts? This is why animals (humans included) CANNOT do photosynthesis NO!!

The Chloroplast The chloroplast is filled with a pigment called CHLOROPHYLL. It is GREEN. The chlorophyll is what actually absorbs the light from the SUN

Why are Plants Green? This graph shows the wavelengths of light that plants ABSORB. They use this light to power the photosynthesis reaction. Notice that they DO NOT use green wavelengths. They REFLECT green light…which is why plants look green.

Chemical Reactions H2O + CO2 H2CO3 Photosynthesis is a CHEMICAL REACTION Chemical reactions look like this… H2O + CO2 H2CO3 Water plus carbon dioxide yields carbonic acid The stuff that comes BEFORE the arrow is called the REACTANTS The stuff that comes AFTER the arrow is called the PRODUCTS REACTANTS PRODUCTS

Plants Students are always confused by the photosynthesis reaction equation The truth is that you already know MOST of it…and have known this since you were in the 2nd grade. What are 3 things ALL plants need to live? Sunlight Water Air (Carbon Dioxide) What are 2 things that plants give us? Oxygen Food

The Photosynthesis Reaction Equation Put the things plants need BEFORE the arrow and the things plants give us AFTER the arrow…and you end up with this CO2 + H2O + sunlight C6H12O6 + O2 This is the equation for the photosynthesis reaction

How does energy from the sun become energy for life How does energy from the sun become energy for life? MY FAVE SONG: THE PHOTOSYNTHESIS SONG - YouTube http://www.youtube.com/watch?feature=endscreen&v=pE82qtKSSH4&NR=1 Organisms that can do photosynthesis are called PRODUCERS. They take RADIANT energy from the SUN and turn it into CHEMICAL energy (FOOD). The chemical energy produced in photosynthesis is in the form of SUGAR. This allows producers to store the energy for later use.

The carbon dioxide comes from the AIR in the ATMOSPHERE The water comes from the GROUND and is sucked up by the plants ROOTS The oxygen is released into the AIR in the ATMOSPHERE The sugar is stored in the plant as food for us to EAT when we need it.

Photosynthesis Animation http://www.growingthenextgeneration.com/agrium-games/Animation/index.htm