Name:                                                                                                 Block:

Prokaryotic & Eukaryotic Ultrastructure Lab

When viewing cells under the microscope, we can often identify multiple cell components and organelles depending on the microscope.  Although Prokaryotes are usually far smaller than Eukaryotes, we are still able to identify features of these cells.  As part of the IB curriculum, you will be expected to identify both types of cells from images as well as particular ultrastructures for each type of cell.  In this lab we will practice these requirements for both cells.

When using the microscopes make sure to never use coarse adjustment while on medium or high power and to check the diaphragm and fine adjustment if you are having trouble finding or focusing on the specimen.

Procedure:

Samples:

In this lab you will draw and label a prepared electron micrograph image of E. coli cell as an example of a prokaryotic cell and draw and label a prepared slide electron micrograph of a liver cell as an example of a eukaryotic cell.  Additionally, specific outlined structures and organelles for each cell type will be identified.  Other cells observed will include tomato and Elodea cells.

Drawings:

When completing your drawings, ensure the following:

Part A: Elodea/Plant Cell Sample

Part B: Prepared electron micrograph E. coli cell

An electron micrograph is a prepared image using an electron microscope.  Drawing the ultrastructure of prokaryotic cell based on an electron micrograph is a required skill.

Ultrastructure Drawing

Electron Micrograph

*Not present in this image are pili & flagellum which can both be found on prokaryotes


Part C: Prepared electron micrograph of liver cell; falsely colored (picture handout)

The following organelles are not present in the image



Tomato Cells

Tomato plants contain  red pigments scattered through the cells called chromoplasts, they do not contain chlorophyll.  The chromoplasts are red, thus giving tomatoes their red color, and any one cell may contain hundreds of chromoplasts.

To make tomato slides, remove a very thin portion of skin or pulp and place it on a microscope slide.  Add 1-2 drops of water and use a cover slip.

Part D: Tomato Skin

 

Part E: Tomato Pulp

Tomato Cells Conclusion & Evaluation:

  1. How does the shape, size, orientation, amount of chromoplasts, and organelle arrangement compare between tomato skin and tomato pulp cells?

  1. Based on question number one, what does this suggest about the tomato cells function?  Be specific and provide detailed explanation.

  1. Provide an example of an animal cell (human cell is acceptable) in which the structure of the cell is directly correlated to the function of the cell.