Prokaryotic cells lack a nucleus and most other organelles. Bacteria and archaea are prokaryotic cells. The document describes drawing and labeling a diagram of the ultrastructure of the prokaryote Escherichia coli (E. coli). The diagram should show the cell wall, plasma membrane, cytoplasm, pili, flagella, ribosomes and nucleoid. Brief notes explaining the function of each structure should then be added to annotate the diagram. Prokaryotes divide through binary fission. There are two domains of prokaryotes - Archaea and Bacteria, which differ in their environments and cell wall composition.

1. 2.1 Prokaryotic cells

2. Prokaryotes
 Pro = before
 Karyon = nucleus
 There are two basic kinds of cells. One kind—a
prokaryotic cell— lacks a nucleus and most other
organelles.
 Bacteria and archaea are prokaryotic cells.
 Prokaryotic organisms appear earliest in Earth's
fossil record.

3.  2.2.1 Draw and label a diagram of the ultrastructure of
Escherichia coli (E. coli) as an example of a prokaryote.
 The diagram should show the cell wall, plasma membrane,
cytoplasm, pili, flagella, ribosomes and nucleoid (region
containing naked DNA).
 2.2.2 Annotate the diagram from 2.2.1 with the functions of each
named structure.
 Draw: Represent by means of pencil lines.
 Label: Add labels to a diagram.
 Annotate: Add brief notes to a diagram or graph.

4. E. coli as an example of a
prokaryote These cell parts are not bound by a
membrane, so they are not called
organelles

5. E. coli as an example of a
prokaryote Plasma membrane: controls entry and
exit, pumping some in by active transport.
Cell wall: forms a protective layer that prevents
damage from outside and also bursting if internal
pressure is high.

6. E. coli as an example of a
prokaryote structures projecting from the cell wall that can be
Pili: hair-like
ratcheted in and out. When connected to another bacterial cell
they can be used to pull cells together.
Cytoplasm: contains enzymes that catalyze the
chemical reactions of metabolism and contains
DNA in a region called the nucleoid.

7. E. coli as an example of a
prokaryote Ribosome: small granular structures that synthesis protein by
translating messenger RNA. Some proteins stay inside the
cell and others are secreted.
Flagella: solid protein structures with corkscrew shape, projecting from cell
wall, which rotates and causes locomotion (movement). Sing.: Flagellum

8. E. coli as an example of a
prokaryote Capsule: protects the bacteria against
phagocytes and
Nucleoid: region of the cytoplasm that contains
naked DNA, which is the genetic information of
the cell.

9. Identify the parts in this
electron micrograph

10. Prokaryotic cells divide by
binary fision

11. Diversity of prokaryotes
 Two domains:
 Archaea: are prokaryotes, many of which live in some of the most
extreme environments on Earth, extremophiles, meaning "lovers of
the extreme."
 Bacteria: Bacteria come in three basic shapes: spherical, rod-
shaped, and spiral-shaped. Nearly all bacteria have a cell wall
outside their plasma membrane. The two types can be
distinguished by a testing method called Gram staining.

12. Homework
 Read 16.1 and 16.2 in the book.