BIO 7:  Lecture 7-8 Preview

Molecules are organized into organelles and organelles are organized into cells, which were recognized in about 1900 as the basis for life.

The Cell Theory

• All living things are made of cells.
• Cells come from other cells by division.
• The cell is the smallest unit of life (having all the properties we associate with a living thing).

Both prokaryotic cells and eukaryotic cells follow the Cell Theory.  Because they are so much smaller, prokaryotic cells are like a studio apartment, while eukaryotic cells are like a mansion.  In a smaller space everything is close at hand, while in a larger space more organization is needed to find things efficiently. 

Cell parts (organelles) help to organize activities within cells.  All cells have parts with specific functions. 

Cells of animals, plants, and bacteria differ a little and have many similarities, since all living things have common requirements.