Photosynthesis

• Biology
• 9th Grade

Learning Goals

• Define the term photosynthesis
  - Identify the reactants and products of photosynthesis 
• Explain the importance of plants as producers of food in a food chain

Food Chain

What do we already
know about plants?

We know that plants . . .

• are alive! 
  - need nutrients (food)
• are producers in food chains & webs
• are made of cells
  - cells have chloroplasts
  
  

We know that the sun . . .

• is not alive
  - contains & releases energy
• made of elements
• fusion 

Photosynthesis

Plants make their own food using energy from the sun

- Photosynthesis needs certain 'ingredients' 

• sunlight
• water
• carbon dioxide

We call these 'ingredients' the reactants for photosynthesis. These different components will come together, chemically react, and form products.

What products form during photosynthesis? . . . 

Parts of Photosynthesis

LIGHT REACTION: Light energy is converted into chemical energy. This is the PHOTO in photosynthesis. The light splits the water molecules, releasing hydrogen, oxygen and energy for the Calvin cycle.

Calvin Cycle: 

That's Why We Need CALVIN

CALVIN CYCLE: Series of reactions that forms simple sugars using carbon dioxide and hydrogen from water. This is the synthesis part of photosynthesis.

What molecule is used to power the Calvin Cycle?

1. Chlorophyll and sunlight
2. Carbon dioxide and water
3. ATP and NADPH
4. Glucose and oxygen

Where does the Calvin Cycle occur within the plant cell?

1. In the cell wall of the plant
2. In the stroma of the chloroplast
3. In the thylakoid membranes
4. In the nucleus of the cell

Photosynthesis

- Photosynthesis is a chemical reaction that makes:

• glucose (food)
  
• oxygen

   carbon dioxide   +  water                         oxygen  +  glucose    

Glucose

Glucose (sugar) is also a food source for animals. Glucose will then be used by both plants and animals to make energy during cellular respiration.

sunlight

chlorophyll

Chlorophyll

Plant cells have an organelle called a chloroplast. The function of the chloroplast is to make food (glucose) during photosynthesis. This corganelle contains chlorophyll which is the pigment that makes plants green. Chlorophyll helps to trap sunllight energy in order to make glucose.

Can we? . . .

• Define the term photosynthesis
  - Identify the reactants and products of photosynthesis 
• Explain the importance of plants as producers of food in a food chain

Define the term photosynthesis

1. plants make food (glucose)
2. animals eat plants
3. animals eat animals
4. animals eat plants and animals

Put the reactants and the products on the correct side of the arrow to complete the chemical equation for photosynthesis:

sunlight/chlorophyll

Reactants:

Products:

Water (H2O)

Carbon Dioxide (CO2)

Glucose (C6H12O6)

Oxygen (O2)

Which organisms are
first in a food chain, providing food for other organisms

1. carnivores
2. producers (plants)
3. omnivores
4. herbivores

Have you ever wondered?

If plants can make their own food, why do Venus Flytraps eat insects?

Nutrients

Plants need more than glucose to carry out life processes. Our next lesson will discuss the othe nutrients needed by plants.

What is the primary purpose of the Calvin Cycle in photosynthesis?

1. To convert carbon dioxide into glucose
2. To produce oxygen as a byproduct
3. To break down glucose for energy
4. To generate ATP for cellular respiration