General features
Autotrophic
Chemotrophic
Phototrophic
heterotrophic
saprotrophic
Phagy
microphagy
pinocytosis
macrophagy
Location of final breakdow
extracellular
intracellular
Functionality of handling
Food vacuole formation--engulfing the particles
Absorption
Filter feeding
Grazing
Food  capture
Kind of food particles
herbivory
carnivory
detritivory

Nutrition
Inorganics vs organics
Chemical elements--chon
Some organic materials
proteins--amino acids
essential
carbohydrates--sugars, cellulose
lipids-fats and fatty acids