Download Photosynthesis

Good Afternoon!
1. Reflect on the Carbon Cycle activity we
completed last class and individually complete
the blank Carbon Cycle worksheet as best as
you can.
• https://www.youtube.com/watch?v=JJxZH
_Y5D4s
How is Carbon emitted into the atmosphere?
• Respiration
• Burning of Fossil Fuels
– Coal
– Oil
– Natural gas
• Decomposition
– When in the soil, bacteria and fungi break down
detritus (dead plant and animal life) and carbon
dioxide is released into the atmosphere.
How is Carbon absorbed from the atmosphere?
• Photosynthesis
• Diffusion into the surface ocean
– The surface ocean absorbs more carbon dioxide
than land
– Cold water absorbs CO2 faster than warm water
• Storage in soil and deep ocean from dead and
decaying plant and animal life
– Carbon circulates from the surface ocean down to
the deep ocean
– Detritus (dead and decaying marine life) collects in
the deep ocean where carbon can be stored for
hundreds of years.
THE SUN: MAIN SOURCE OF
ENERGY FOR LIFE ON EARTH
AN OVERVIEW OF PHOTOSYNTHESIS
• Photosynthesis is the process by which
autotrophic organisms use light energy to
make sugar and oxygen gas from carbon
dioxide and water
Carbon
dioxide
Water
Glucose
PHOTOSYNTHESIS
Oxygen
gas
Light Energy Harvested by Plants &
Other Photosynthetic Autotrophs
6 CO2 + 6 H2O + light energy → C6H12O6 + 6
O2
Food Chain
THE FOOD WEB
WHY ARE PLANTS GREEN?
Plant Cells
have Green
Chloroplasts
The thylakoid
membrane of the
chloroplast is
impregnated with
photosynthetic
pigments (i.e.,
chlorophylls,
carotenoids).
THE COLOR OF LIGHT SEEN IS THE
COLOR NOT ABSORBED
• Chloroplasts
absorb light
energy and
convert it to
chemical energy
Light
Reflected
light
Transmitted
light
Chloroplast
Absorbed
light
Chloroplasts: Sites of Photosynthesis
• Photosynthesis
– Occurs in chloroplasts, organelles in certain
plants
– All green plant parts have chloroplasts and carry
out photosynthesis
• The leaves have the most chloroplasts
• The green color comes from chlorophyll in the
chloroplasts
• The pigments absorb light energy
• The location and structure of chloroplasts
Chloroplast
LEAF CROSS SECTION
MESOPHYLL CELL
LEAF
Mesophyll
Stomata
CHLOROPLAST
Intermembrane space
Outer
membrane
Granum
Grana
Stroma
Inner
membrane
Stroma
Thylakoid
Thylakoid
compartment
How does Carbon get back to the
Atmosphere?
Animals Eat Plants
• When organisms eat
plants, they take in the
carbon from the plant.
• Some of it becomes part
of their own bodies.
• Some of it will be
released to the
atmosphere.
How does Carbon get back to the
Atmosphere?
• This process is called
“Respiration!”
Equation:
Food + Oxygen  Carbon Dioxide + Water
C6H12O6 + O2 CO2 + H20
How does Carbon get back to the
Atmosphere?
• The Goal of
“Respiration” is to
break down glucose
and release energy
for cell processes.
• Since all living organisms need this
energy, all living organisms do
respiration…even plants!!!
Where in the cell does Respiration
take place in the cell?
• This happens in a
structure in the cell
called the
mitochondria.