I. THE EUKARYOTIC CELL

A. COMPOSITION AND FUNCTIONS OF EUKARYOTIC CELLULAR STRUCTURES

2. The Cell Wall

Fundamental Statements for this Learning Object:

1. Algae, fungi, and plant cells have a cell wall; animal cells and protozoans lack cell walls.
2. The rigid, tightknit, polysaccharide molecular structure of the cell wall helps the cell resist osmotic lysis.

 

LEARNING OBJECTIVES FOR THIS SECTION

The cell is the basic unit of life. Based on the organization of their cellular structures, all living cells can be divided into two groups: prokaryotic and eukaryotic (also spelled procaryotic and eucaryotic). Animals, plants, fungi, protozoans, and algae all possess eukaryotic cell types. Only bacteria have prokaryotic cell types.

Eukaryotic cells are generally much larger and more complex than prokaryotic. Because of their larger size, they require a variety of specialized internal membrane-bound organelles to carry out metabolism, provide energy, and transport chemicals throughout the cell.

We will now look at the cell wall of eukaryotic cells.

The Cell Wall

When present, the cell wall (see Fig. 32 and Fig. 39) is quite simple. In algae and plant cells, the cell wall is usually composed of cellulose. In molds it is composed of chitin and/or cellulose. Animal cells and protozoans lack cell walls. As with bacteria, the rigid, tightknit molecular structure of the cell wall determines shape and helps resist osmotic lysis (def).

• QUIZ YOURSELF ON THIS SECTION

Gary E. Kaiser, Ph.D.
Professor of Microbiology
The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work The Grapes of Staph at https://cwoer.ccbcmd.edu/science/microbiology/index_gos.html.