Carbon and Energy Sources of Organisms

Vocabulary flashcards covering the key nutritional classifications—carbon and energy sources—highlighted in the lecture notes.

Autotroph

Organism that uses inorganic CO₂ as its carbon source, producing its own organic compounds through photosynthesis or chemosynthesis (producer).

Heterotroph

Organism that obtains complex organic carbon compounds by consuming other organisms (consumer).

Phototroph

Organism that acquires energy for electron transfer from light.

Chemotroph

Organism that acquires energy for electron transfer by breaking chemical bonds in molecules.

Organotroph

Chemotroph that uses organic compounds as its energy (electron) source.

Lithotroph

Chemotroph that uses inorganic compounds as its energy (electron) source.

Producer

General term for organisms—typically autotrophs such as plants, algae, and some bacteria—that manufacture their own food and supply energy to ecosystems.

Consumer

General term for organisms—typically heterotrophs such as animals, fungi, and many bacteria—that ingest other organisms to obtain energy and nutrients.

Chemoautotroph

Organism that uses inorganic chemicals for energy and CO₂ as its carbon source, producing organic matter via chemosynthesis (e.g., sulfur-oxidizing bacteria in hydrothermal vents).

Cyanobacteria

Blue-green, photosynthetic bacteria that act as photoautotrophs, using light and CO₂ to synthesize organic material and often bloom in warm, nutrient-rich waters.