Rucete ✏ Campbell Biology In a Nutshell
Unit 2 THE CELL — Concept 10.1 Photosynthesis Feeds the Biosphere
Photosynthesis is the process by which light energy is transformed into chemical energy, supporting nearly all life on Earth either directly or indirectly.
Autotrophs: The Producers
Autotrophs make their own organic molecules from CO₂ and inorganic materials
They do not rely on other living organisms for food
Photoautotrophs use sunlight as an energy source—includes plants, algae, and some prokaryotes
Autotrophs are the base of the food chain and sustain all non-autotrophs
Heterotrophs: The Consumers
Heterotrophs obtain organic material by consuming other organisms or organic matter
They include animals, fungi, and many prokaryotes
Decomposers, like fungi and bacteria, feed on dead material and waste
All heterotrophs ultimately depend on autotrophs for energy and oxygen
Fossil Fuels and Photosynthesis
Fossil fuels formed from ancient autotrophs store sunlight energy from the past
Biofuel strategies (e.g., using photosynthetic algae) aim to recycle current sunlight energy
Using algae near CO₂-rich environments (like factories) enhances photosynthetic output and sustainability
In a Nutshell
Photosynthesis sustains life by converting sunlight into chemical energy. Autotrophs feed themselves and support all heterotrophs, including humans, making them essential to Earth's biosphere.