We have moved from within prokaryotic and eukaryotic cells to the outside, and this should provide a framework for thinking about the make-up of microbes. Some ideas that you should take away from this chapter are:
- While not obvious in the microscope, the prokaryotic cell is organized into functional units: (i) The nucleoid organizes, manages and replicates the DNA. (ii) The cytoplasm carries out many of the reactions of the cell including biosynthesis and catabolism. (iii) The ribosomes are the site of protein synthesis. (iv) The membrane defines the borders of the cell and serves as a barrier to most molecules. (v) The cell wall defines a microbes shape and helps protect it from the environment.
- The building blocks that make up the average prokaryote are also found in all living things on this planet. We share more things in common with microbes than there are features that distinguish us.
- Although prokaryotes are small, they have a huge amount of molecular complexity. In a sense, multicellular organisms deal with different problems by forming different cell types, but prokaryotes must adapt each cell to specific environmental conditions. They are stunningly clever little machines.
In subsequent chapters we will learn what all these various parts are doing.[Prev]