How do we (animals) get food?
We EAT FOOD in the form of other
organisms. That food is broken down
and used by our cells.
How do plants get their food?
Plants and other
organisms make food
through a process that
uses energy, we call it
PHOTOSYNTHESIS
Photosynthesis
• Photosynthesis takes place in the chloroplasts.
• Chlorophyll is a chemical in the
chloroplast that absorbs light energy.
• It makes the leaves green.
Reactants (what goes in)
• Carbon dioxide (CO2)
• Water (H2O)
• Energy (Light)
Products (what comes out)
• Oxygen (O2)
• Glucose or Sugar (C6H12O6)
Formula for Photosynthesis
6CO2 + 6H2O + Light Energy
C6H12O6 + 6O2
2 Stages
• Light-Dependent Reaction
• Light-Independent Reaction
Calvin Cycle
Stage 1: Light-Dependent
Reaction
• Takes place in the thylakoid membranes.
• Light energy becomes chemical energy.
• Water is split and oxygen is given off.
Stage 2: Light-Independent
Reaction or Calvin Cycle
• Carbon dioxide (CO2) and chemical energy
are used to make sugar or food for the plant.
• Takes place in the Stroma of the
chloroplast.
Review
1. What are the reactants of photosynthesis?
Carbon dioxide (CO2), Water (H2O), and
Light Energy
2. What are the products of photosynthesis?
Oxygen (O2) and Sugar or Glucose
(C6H12O6)
3. Where does photosynthesis occur?
Chloroplast in Leaf Cells
Photosynthesis in a Nutshell
1. Light Dependent Reaction: Using water,
light energy becomes chemical energy and
oxygen is given off.
2. Calvin Cycle: Carbon dioxide (CO2) and
chemical energy are used to make sugar or
food for the plant.
Takes place in the mitochondria.
Cellular Respiration
C6H12O6 + O2
CO2 + H2O + energy
Cell Respiration
Cellular Respiration
• Breaks down food (sugar) to produce
ATP (energy-storing molecules)
• 3 stages
1. glycolysis
2. citric acid cycle
3. electron transport chain
Glycolysis
• In glycolysis, we begin the breakdown of
sugar.
Kreb’s Cycle or Citric Acid
Cycle
• We continue to breakdown the sugar.
• Carbon dioxide is released.
Electron Transport Chain
• This is where we make all of our energy
storing molecules called ATP.
• Water is also made as a byproduct.
How are these process related?
Gas Exchange
Oxygen (O2)
Carbon Dioxide (CO2)