Transcript Research - Photosynthesis

Photosynthesis
(Let’s get into this)
Jan Ingenhousz & Julius Robert Mayer
Natalie Marulanda and Clare Robinson
Prior Knowledge
J.B. Van Helmont
• Scientists previously thought that plants got
their mass from soil
• In early 1600s, Helmont observed a tree for
five years
• He incorrectly concluded that
mass of plants come from the
absorption of water
(Di Giuseppe et al, 2003)
Prior Knowledge
Stephen Hales
• In 1727, Hales wrote a book that accounts a
lot of experiments on plant physiology
• Realized that light is necessary for plant
growth
• He had a theory that plants
absorbed air through their
leaves for nourishment and
led a series of experiments
(Stephen Hales)
Prior Knowledge
Joseph Priestley
• He discovered that gases in air play a role in
photosynthesis
• Led an experiment with a candle and a
mint plant
• He proved that plants release a gas that
supports combustion
(Di Giuseppe et al, 2003)
Experiments & Results
Jan Ingenhousz 1779
• In 1779, he tested the effects of sunlight and
darkness on aquatic plants
• When the plant is in sunlight, oxygen is
produced by green parts of the plant
• In darkness, oxygen is not produced
• Sunlight is vital for
photosynthesis to occur
(Jan Ingenhousz)
Experiments & Results
Julius Robert von Mayer
• In 1842, he stated that “energy can be
neither created nor destroyed”
• Photosynthesis is a conversion of light energy
into chemical energy to enable plants to
produce their own food in the
form of simple sugars
• The sun is the source of energy
for plants
(Julius von Mayer)
What Did We Learn?
• The green parts of plants (chlorophyll)
release oxygen when exposed to sunlight
• There exists a natural cycle of gases
• Sunlight is the source of energy for plants
• Sunlight is essential for all living organisms
Works Cited
Di Giuseppe, Maurice, et al. (2003). Nelson Biology 12 (pp. 149-150).
Toronto, ON: Nelson.
Jan Ingenhousz - Wikipedia, the free encyclopedia. (n.d.). Wikipedia,
the free encyclopedia. Retrieved November 14, 2010, from
http://en.wikipedia.org/wiki/Jan_Ingenhousz
Jan Ingenhousz — Biography. (n.d.). Macroevolution.net – All you
wanted to know and more. Retrieved November 14, 2010, from
http://www.macroevolution.net/jan-ingenhousz.html
Julius von Mayer - Wikipedia, the free encyclopedia. (n.d.). Wikipedia,
the free encyclopedia. Retrieved November 14, 2010, from
http://en.wikipedia.org/wiki/Julius_von_Mayer
Stephen Hales - Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the
free encyclopedia. Retrieved November 14, 2010, from
http://en.wikipedia.org/wiki/Stephen_Hales