Biology · StudentHub Lesson
Photosynthesis
How plants convert light energy into chemical energy stored as glucose.
What you will learn
- Explain the overall purpose of photosynthesis
- Identify reactants and products
- Describe light-dependent and light-independent reactions
- Explain the role of chlorophyll
- Relate photosynthesis to the food chain
Watch the lesson
Photosynthesis (UPDATED) · Amoeba Sisters
Watch on YouTubeTopic notes
Main Idea
Photosynthesis is the process plants, algae, and some bacteria use to convert light energy into chemical energy stored in glucose.
Key Concepts
- Occurs in chloroplasts, mainly in leaf cells
- Requires sunlight, water, and carbon dioxide
- Produces glucose and oxygen
Definitions
- Chlorophyll: green pigment that absorbs light energy
- Stomata: tiny pores that allow gas exchange
- Chloroplast: organelle where photosynthesis occurs
Processes
- Light-dependent reactions capture sunlight and produce ATP and NADPH, splitting water and releasing oxygen
- Light-independent reactions (Calvin cycle) use ATP and NADPH to build glucose from CO2
Equation
6CO2 + 6H2O + light energy -> C6H12O6 + 6O2
Examples
See questions below for applied reasoning.
Common Mistakes
- Confusing photosynthesis with cellular respiration
- Thinking photosynthesis only occurs in leaves
- Forgetting oxygen is a byproduct, not an input
Key concepts
Important terms
- Chlorophyll
- Green pigment in chloroplasts that absorbs light energy for photosynthesis.
- Chloroplast
- Organelle in plant cells where photosynthesis takes place.
- Stomata
- Small pores on leaves that allow CO2 in and O2 out.
Quick revision
- Photosynthesis converts light energy to chemical energy
- Occurs in chloroplasts
- Inputs: CO2, water, light
- Outputs: glucose, oxygen
- Two stages: light-dependent and light-independent
- Chlorophyll absorbs light
- Opposite of cellular respiration
Check your understanding
Question 1 · Multiple choice
Where does photosynthesis mainly occur in plant cells?
Question 2 · Multiple choice
What gas is released as a byproduct of photosynthesis?
Question 3 · True or false
Photosynthesis requires carbon dioxide as an input.
Question 4 · Short answer
Name the pigment that absorbs light for photosynthesis.
Question 5 · Short answer
Write the overall equation for photosynthesis.
Done with Photosynthesis?
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