PHOTOSYNTHESIS
What is the equation for
photosynthesis?
Where does the photosynthesis
take place in the plant?
 In the leaves
 In the chloroplasts – due to the presence of
chlorophyll
Where does the photosynthesis
take place in the plant?
What does a plant need to begin
the process of photosynthesis?
INPUTS:
 Sunlight
 Water (H2O)
 Carbon dioxide (CO2)
Where/how does a plant
get those items?
 CO2 – from the stomata. Stomata are “mouthlike” pores on the outside of leaves.
Where/how does a plant
get those items?
 H2O – from roots. Travels up through the roots to
the leaves through the xylem (“veins” in plants)
Where/how does a plant
get those items?
 Sunlight – absorbed by the chloroplasts
What does the plant make
during photosynthesis?
OUTPUTS:
Sugar
Oxygen
What happens to the
oxygen the plant makes?
 It gets released through the stomata back
into the atmosphere for animals to breathe
in!
What does the plant do
with sugar?
 Sugar is it’s food!
What does the plant do
with sugar?
 Makes starches/carbohydrates (a bunch of sugar
molecules together) and stores it for later.
What does the plant do
with sugar?
 Plants store their sugars in their phloem (another
“vein” in plants).
Why do plants want to
store sugar?
 Plants want to store sugar for when it’s dark
and they can’t make their own food.
Why do plants need to be
in soil?
 To get other mineral nutrients from the soil.
 Just like you need vitamins for healthy cells –
plants need minerals too!
 Plants take these mineral nutrients from the soil:
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Nitrogen
Phosphorous
Sulfur
Magnesium
Potassium
Calcium
What do plants do with the mineral
nutrients they get from the soil?
 They use them to make up parts of their
cells.
 Plants use them to make their organelles.
Remember: everything is made of molecules!
Plants use those mineral nutrients to make
more proteins, lipids, etc…
Why do we care about
photosynthesis?
 BECAUSE WITHOUT PLANTS,
THERE IS NO US!
No plants = No food = No animals
Photosynthesis Recap
 http://www.nbclearn.com/portal/site/learn/chem
istry-now/chemistry-of-green
CELLULAR RESPIRATION
Glucose can be used by the
plant in two ways:
1. Glucose molecules can be
used by the plant as building
blocks.
2. Glucose molecules can be
broken down by the plant to
release energy.
Be careful…
Food ≠ Energy
Be careful…
Food ≠ Energy
Energy = The ability to do work
Be careful…
Food ≠ Energy
Energy = The ability to do work
Sugar (glucose) does not do
work, but it can be broken
down thereby releasing energy.
Photosynthesis
The process doesn’t produce energy directly.
In fact, it requires energy.
Where does that energy come from?
Remember…
All chemical reactions can move
in either direction.
What would the reaction for
photosynthesis look like in reverse?
Cellular Respiration
Cellular respiration is the process
necessary for ALL living
organisms to produce energy.