learning goal: explain how the sun supplies living things with the energy they need. explain...
TRANSCRIPT
Tuesday 10/27 Learning Goal: Explain how the sun
supplies living things with the energy they need. Explain photosynthesis.
Warm up: Why do plants need light?
Homework: Packet pages 21, 22, 23
Chapter 3, Section 3
Photosynthesis
Sources of Energy Photosynthesis: the process by which a
cell captures energy in sunlight and uses it to make foodo Photo– means “light”, synthesis– means
“putting together” Nearly all living things obtain energy either
directly or indirectly from the energy of sunlight captured during photosynthesis
Review Autotroph
o an organism that makes their own foodo What are some examples?
Heterotropho an organism that cannot make their own foodo What are some examples?
Fungi– absorb their food from other organisms
The Two Stages of Photosynthesis
1. Capturing the sun’s energy
2. Producing sugars
Both stages must occur in the correct order
Stage 1: Capturing the Sun’s Energy
Energy capturing process occurs mostly in leaves
The green color comes from pigments– colored chemical compounds that absorb light
The MAIN photosynthetic pigment in chloroplasts is called CHLOROPHYLL
Chlorophyll captures light energy and uses it to power the second stageof photosynthesis…
Stage 2: Using Energy to Make Food
Cell uses captured energy to produce sugars
The cell needs two raw materials1. water – enters plant through roots and move upward
to the leaf2. carbon dioxide– enters through openings called
stomata
Once in the leaves the water and carbon dioxide move into the chloroplasts….
Stage 2: Using Energy to Make Food
Inside the chloroplasts undergo a series of chemical reactions
Chemicals are the products of the reactions (2)o Six-carbon sugar (use this energy to carry out cell
functions)o Oxygen (exits leaf through stomata)
Fun Fact: Almost all oxygen in Earth’s atmosphere was produced by living things through the
process of photosynthesis
The Photosynthesis Equation
The arrow stands for YIELDS
Raw Materials Products
What happens to the sugar produced in photosynthesis?
Plants use it for food
Some sugar is made into other compounds, such as cellulose
Some sugar is stored in the plant’s cells for later use