Photosynthesis: Using Light to Make Food

1. Living things that are able to make their own food without using organic molecules derived from any other living thing
2. Use the energy of light to produce organic molecules are called photoautotrophs
3. Most plants, algae, protists and some prokaryotes are photoautotrophs

1. Organelles consisting of photosynthetic pigments, enzymes and other molecules grouped together in membranes
2. Major sites of photosynthesis
3. Integrates the two stages of photosynthesis and makes sugar from carbon dioxide

1. Light absorbing pigment in chloroplasts
2. Responsible for plants' green color
3. Plays central role in converting solar energy to chemical energy
4. Concentrated in the cells of the mesophyll (green tissue in interior of leaf

Tiny pores in the leaf that allow carbon dioxide to enter and oxygen to exit

Deliver water absorbed by roots

1. Dense fluid within the chloroplast
2. Enclosed by an envelope of two membranes

1. Systems of interconnected membranous sacs
2. Segregates the stroma from the thylakoid space
3. Concentrated in stacks called grana

1. Energy found in sunlight
2. Travels in waves
3. Distance between crests of the waves is wavelength

1. Discrete packets of light
2. Fixed quantity of light energy
3. The shorter the wavelength the greater the energy

1. Molecules that absorb light
2. Built into the thylakoid membrane
3. (Plant pigments) absorb some wavelengths of light and transmit others
4. Wavelengths transmit different colors (ex. chlorophyll transmits green)

Blue violet and red light; green

Blue and orange; yellow-green

Blue-green; yellow and orange

1. Results from solar energy warming the planet
2. Gases (greenhouse gases) in the atmosphere reflect heat back to earth to keep the planet warm and supporting life

1. Increasing concentrations of green house gases slowly rise Earth's surface temperature
2. Rise in carbon dioxide is due to combustion of carbon based fossil fuels
3. Consequence: melting polar ice, changing weather patterns, spread of tropical disease
4. Photosynthesis might be able to mitigate increase in atmospheric carbon dioxide