all living things are made of carbohydrates, fatty acids, nucleic acids amino acids

cells convert molecules from the environment into new molecules (shifting)

viruses

• don't have membranes or ribosomes, they take over other cells to do those things (debated to be/not be a living thing)
• they're protein and genetic material (either RNA or DNA)

prokaryotes - single cell - basically bacterial - doesn't have a nucleus (before nucleus)

eukaryotes - multi-cell - compartmentalized - has a nucleus (after nucleus)