1. Photosynthesis and Carbon Cycle Review Reference Lesson 13 in text

2. Photosynthesis  Photo – Greek meaning “pertaining to light”  Synthesis – Greek meaning “putting together”  Autotrophs combine light and substances to create sugar (food) for themselves  Photo – Greek meaning “pertaining to light”  Synthesis – Greek meaning “putting together”  Autotrophs combine light and substances to create sugar (food) for themselves

3. Microbes  Microbes are any microscopic organism  Base of marine food webs  Very fast growth rate and life cycles  More oxygen is produced in the ocean than on continents  Microbes are any microscopic organism  Base of marine food webs  Very fast growth rate and life cycles  More oxygen is produced in the ocean than on continents

4. Ozone  Phytoplankton – plant like microbes  Photosynthetic bacteria – Cyanobacteria  Oldest fossil found on Earth – 3.5 billion years ago  Before this – no oxygen existed on Earth  Produced Ozone - a compound found in the upper atmosphere  Before this, no organisms could survive on land due to UV light damage  Phytoplankton – plant like microbes  Photosynthetic bacteria – Cyanobacteria  Oldest fossil found on Earth – 3.5 billion years ago  Before this – no oxygen existed on Earth  Produced Ozone - a compound found in the upper atmosphere  Before this, no organisms could survive on land due to UV light damage People are nuts

5. Oldest fossils on Earth

6. Cyanobacteria

7. Photosynthetic Microbes  Diatoms  Contain chloroplasts  Sunlight can penetrate their clear, silica shells  Dinoflagellates  Contain chloroplasts  Can also ingest food (animal –like)  Diatoms  Contain chloroplasts  Sunlight can penetrate their clear, silica shells  Dinoflagellates  Contain chloroplasts  Can also ingest food (animal –like)

8. Photosynthesis  Occurs in an organelle  chloroplast  Converts light energy  chemical energy  6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2  Occurs in an organelle  chloroplast  Converts light energy  chemical energy  6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2

9. Seasonal Photosynthesis  The tilt of the Earth and its revolution around the Sun result in seasonal differences in light availability.  Therefore, there are seasonal differences in photosynthesis— both on land and in the ocean.  Nearly 50% of sun entering our atmosphere is absorbed by oceans  The tilt of the Earth and its revolution around the Sun result in seasonal differences in light availability.  Therefore, there are seasonal differences in photosynthesis— both on land and in the ocean.  Nearly 50% of sun entering our atmosphere is absorbed by oceans

10. Photic Zone  Sunlight penetrates only about 200 meters (~650 feet)  Photosynthesis can only occur in this top layer, called the photic zone.  Sunlight penetrates only about 200 meters (~650 feet)  Photosynthesis can only occur in this top layer, called the photic zone.

11.  What else besides light is necessary for photosynthesis?

12. Carbon Dioxide  One major source of carbon dioxide (CO 2 ) in the ocean is from marine organisms.  Living things release CO 2 as a byproduct of respiration.  CO 2 is released from decomposers feeding on dead organisms.  One major source of carbon dioxide (CO 2 ) in the ocean is from marine organisms.  Living things release CO 2 as a byproduct of respiration.  CO 2 is released from decomposers feeding on dead organisms.

13. Nutrients  Necessary nutrients include:  Nitrogen  Phosphorus  Potassium  Iron  Phytoplankton absorb these directly through their cell membranes  2 sources:  Released when living matter decomposes  Runoff from land  Necessary nutrients include:  Nitrogen  Phosphorus  Potassium  Iron  Phytoplankton absorb these directly through their cell membranes  2 sources:  Released when living matter decomposes  Runoff from land

14. Chlorophyll and Enzymes  Pigments – light absorbing molecules in autotrophs  Chlorophyll – primary pigment in chloroplasts  Reflects green  Absorbs red and blue wavelengths of light  Enzymes are proteins found in the membranes of organisms  Speed up chemical reactions  Especially in Photosynthesis  Pigments – light absorbing molecules in autotrophs  Chlorophyll – primary pigment in chloroplasts  Reflects green  Absorbs red and blue wavelengths of light  Enzymes are proteins found in the membranes of organisms  Speed up chemical reactions  Especially in Photosynthesis

15. Carbon Cycle  Ocean holds >90% of Earth’s Carbon Dioxide  In addition to Photosynthesis, also used by molluscs to build their CaCo 3 shells  Plants take in CO 2 to make carbohydrates  Carbs get passed through food chain  Ocean holds >90% of Earth’s Carbon Dioxide  In addition to Photosynthesis, also used by molluscs to build their CaCo 3 shells  Plants take in CO 2 to make carbohydrates  Carbs get passed through food chain

16. Carbon Cycle  Buried remains of carbon-rich organisms become incorporated into rocks  Eventually remains are compressed into fossil fuels  Burning fossil fuels release CO 2 into atmosphere  Ocean absorbs ~50% released into atmosphere  Buried remains of carbon-rich organisms become incorporated into rocks  Eventually remains are compressed into fossil fuels  Burning fossil fuels release CO 2 into atmosphere  Ocean absorbs ~50% released into atmosphere

17. Carbon Cycle Sources  CO 2 also released by underwater and land volcanoes  CO 2 and CH 4 (methane) released through mining and agriculture  Carbon released through deforestation  CO 2 also released by underwater and land volcanoes  CO 2 and CH 4 (methane) released through mining and agriculture  Carbon released through deforestation

18. Summarize Photosynthesis Sources IngredientsSources Light Carbon Dioxide Nutrients Chlorophyll Enzymes

19. Summarize Photosynthesis Sources IngredientsSources LightSun Carbon DioxideRespiration, Decomposition, Undersea Vents and Volcanoes, Breakdown of rocks/shells NutrientsDecomposition Runoff ChlorophyllContained within the phytoplankton EnzymesContained within the phytoplankton

20. Carbon Cycle