Photosynthesis and Carbon Cycle Review Reference Lesson 13 in text.
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Transcript of Photosynthesis and Carbon Cycle Review Reference Lesson 13 in text.
Photosynthesis and Carbon Cycle Review
Reference Lesson 13 in text
Photosynthesis
Photo – Greek meaning “pertaining to light”Synthesis – Greek meaning “putting together”Autotrophs combine light and substances to
create sugar (food) for themselves
Microbes
Microbes are any microscopic organismBase of marine food websVery fast growth rate and life cyclesMore oxygen is produced in the ocean than on
continents
Ozone
Phytoplankton – plant like microbesPhotosynthetic bacteria – Cyanobacteria
Oldest fossil found on Earth – 3.5 billion years ago
Before this – no oxygen existed on EarthProduced Ozone - a compound found in the upper atmosphere
Before this, no organisms could survive on land due to UV light damage
People are nuts
Oldest fossils on Earth
Cyanobacteria
Photosynthetic Microbes
Diatoms Contain chloroplasts
Sunlight can penetrate their clear, silica shells
DinoflagellatesContain chloroplasts
Can also ingest food (animal –like)
Photosynthesis
Occurs in an organelle chloroplast
Converts light energy chemical energy
6CO2 + 6H2O C6H12O6 + 6O2
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
Photic Zone
Sunlight penetrates only about 200 meters (~650 feet)
Photosynthesis can only occur in this top layer, called the photic zone.
What else besides light is necessary for photosynthesis?
Carbon Dioxide
One major source of carbon dioxide (CO2) in the ocean is from marine organisms.
Living things release CO2 as a byproduct of respiration.
CO2 is released from decomposers feeding on dead organisms.
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
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
Carbon Cycle
Ocean holds >90% of Earth’s Carbon Dioxide
In addition to Photosynthesis, also used by molluscs to build their CaCo3 shells
Plants take in CO2 to make carbohydrates
Carbs get passed through food chain
Carbon Cycle
Buried remains of carbon-rich organisms become incorporated into rocks
Eventually remains are compressed into fossil fuelsBurning fossil fuels release CO2 into atmosphere
Ocean absorbs ~50% released into atmosphere
Carbon Cycle Sources
CO2 also released by underwater and land volcanoes
CO2 and CH4 (methane) released through mining and agriculture
Carbon released through deforestation
Summarize Photosynthesis Sources
Ingredients Sources
Light
Carbon Dioxide
Nutrients
Chlorophyll
Enzymes
Summarize Photosynthesis Sources
Ingredients Sources
Light Sun
Carbon Dioxide Respiration, Decomposition, Undersea Vents and Volcanoes, Breakdown of rocks/shells
Nutrients DecompositionRunoff
Chlorophyll Contained within the phytoplankton
Enzymes Contained within the phytoplankton
Carbon Cycle