Photosynthesis1

• Biology
• 9th Grade

Miss Brianna Murray

Photosynthesis

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

What do we already
know about plants?

What do we already
know about the sun?

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 

Autotrophs

Autotrophs (auto = self, troph = feeding)

- Organisms that can produce their own food
- Photoautotrophs (photo = light): make food from light energy

- Chemoautotrophs (chemo = chemicals): make food from chemical energy

Vs.

Heterotroph (hetero = other)

- Organisms that must feed on other organisms for food
- Herbivores, Omnivores, Carnivores, Detritivores  

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? . . . 

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.

Food Chain

Leaf tissue 

Leaf Tissue

Waxy cuticle: helps prevent unwanted water loss

Epidermis: In the lower level, this layer of cells contain guard cells and stomata which help regulate gas exchange between the leaf and the environment 

Palisade mesophyll: this layer of cells have a high amount of chloroplasts in them . . . why might the top layer of the leaf have more chloroplasts?

Veins: bring water and nutrients around the plant

Spongy mesophyll: air spaces allow diffusion of gases rapidly

Guard cells: open and close to allow for gas exchange and water (transpiration) -- specialized cells

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

Define the term autotroph:

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

Which organisms are
considered autotrophs?

1. Fungus
2. Plants and algae
3. Deep sea bacteria
4. Herbivores

waxy cuticle

upper epidermis

palisade mesophyll

spongy mesophyll

stomata & guard cells

veins

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.