Energy and Life Chapter 8.1

Autotrophs vs. Heterotrophs Energy comes from food BUT most of foods energy comes from the sun Plants/Animals use suns energy to obtain food 2 ways organisms obtain food AUTOTROPH HETEROTROPH

Autotrophs Use light energy from sun to make their own food PLANTS, some BACTERIA

Heterotrophs Obtain energy from foods they consume Animals, humans

Traits that they share Must release the energy from sugar and compounds to LIVE! Get energy from sun Autotrophs – directly Heterotrophs – indirectly

Chemical Energy ATP is basic energy source for all cells Energy can be stored in chemical compounds in organisms Living things use chemical fuels ATP – adenosine triphosphate 1 adenine 5 carbon sugar – ribose 3 phosphate groups (key to ATP’s ability to store/release energy ATP is basic energy source for all cells Like a charged battery!

Chemical Energy ATP (charged battery) Energy stored in bonds between phosphates Break one phosphate off & release energy Cells use that energy for cellular activities Now left with ADP – partially charged battery

ATP Animation

ATP – Bill Nye http://www.goldiesroom.org/Multimedia/Movie_Clips/07%20Respiration/What%20is%20ATP.wmv

FYI ATP not stored in large quantities in cell because….. Not a good molecule for storing energy Glucose better for storing energy

WARM UP What is the molecule we learned about yesterday that was a like a “charged battery”? A. ADP B. APP C. Glucose D. ATP

PHOTOSYNTHESIS Ch. 8.2 PHOTOSYNTHESIS Ch. 8.2

Photosynthesis Song http://www.youtube.com/watch?v=C1_uez5WX1o

Photosynthesis Photosynthesis – using energy of sunlight to convert water & CO2 into sugars, starches, and O2. light CO2 + H20  C6H1206 + O2 (Carbon dioxide + water  glucose + oxygen) Carbon dioxide comes from air or water

Light and pigments Water & carbon dioxide Low energy materials They turn low energy raw materials into high energy sugars using…. Using Light and pigments

Light Sun’s energy is in form of light Sunlight is a mixture of different wavelengths of light Visible spectrum – visible to eye Different colors of light = different wavelengths

Pigments Pigment – light absorbing molecule Chlorophyll main pigment for plants 2 main types Chlorophyll a Chlorophyll b Chlorophyll absorbs blue-violet and red regions of visible spectrum Chlorophyll does not absorb Green region of visible spectrum Carotene another type of pigment Red and orange pigment

Pigments and energy When you absorbs light, also absorb energy from that light When chlorophyll absorbs light Energy transferred to electrons in chlorophyll raises energy levels of electrons High energy electrons make photosynthesis work.