Download major food source of the world

Introduction to Plants
major food source of the world
Background
Q: When the first organic molecules began forming on Earth,
what wasn’t present in the atmosphere?
Q: What is now present in the atmosphere?
Oxygen Revolution
1. Oxygen first produced, dissolved into the ocean
2. Dissolved oxygen @ saturated levels
3. Combined with iron in ocean and solidified into iron
oxide
4. Oxygen then began to enter the atmosphere
Where is the evidence of oxygen in ocean?
Evidence supporting dissolved oxygen in ocean
Iron Oxide (Fe2O3)
What do plants provide for the PLANET?
Common Knowledge that plants
produce oxygen… but how?
Consider a large oak tree, where
does its mass come from?
light, air, soil or water?
Look at Brief History
Imperfect by nature
“Some 3.4 billion years ago, a puddle of green slime kick-started a process that would
terraform an inhospitable Earth into a planet with oxygen and ecosystems. Ancient cyanobacteria
had stumbled onto something incredible: using photons of light to split water, and channeling the
resultant burst of energy to turn carbon from the air into sugar.
Today, that process—photosynthesis—is the basis of nearly every food web and ecosystem on
our planet. It’s also been responsible for recycling the atmosphere these last few eons, by drawing
down CO2 and releasing oxygen as a waste product. If plants stopped spinning sunlight into sugar
tomorrow, every animal on Earth would soon starve and asphyxiate.”
-
courtesy of Maddie Stone (7/4/2015)
WHAT MAKES PLANTS SO SPECIAL?
❏ Plants are
made of cells
❏ They have a
cell
membrane,
made of
phospholipids
❏ Is anything
unfamiliar in
diagram?
Cell terminology
Eukaryote- organism whose cells
have a nucleus and membrane bound
organelles
Organelle- a specific structure
that carries out specific
activities for the cell.
Cytoplasm- fluid space inside cells
●
Plants are eukaryotes and their
special organelle is a
chloroplast
Entering a Cell
Plant Cell Terminology
Cell wall- rigid structure surrounding a cell membrane that
provides extra support in maintaining cell shape
Vacuole- organelle that stores water for plant cells
Chloroplast- organelle that absorbs light (form of energy)
to make carbohydrates from carbon dioxide and water.
thylakoid- location where energy is captured and
transferred to electrons in the chlorophyll.
granum- stack of thylakoids
Up NExt: Photosynthesis
Metabolism: involves either using
energy to build molecules or breaking
down molecules in which energy is
stored