Cell Structure

Cell Structure and Organisms

Students who are going to study in health or science-related fields will need to understand cell structure for their college entrance exams.

This post will have a look at cell structure, including single-celled organisms like bacteria and yeast.

It will also discuss the structure of plant cells and animal cells.

When discussing cell structure, it is important to remember that cells are the building blocks from which all living organisms are made.

Single-Celled Organisms

Bacteria and other single-celled organisms can be identified as such because these cells do not have a nucleus.

Because of this, single-celled organisms are also called prokaryotic cells.

(“Pro” means “before” and “karyon” means “nucleus.”)

Bacterial cells are in capsule form. Their structure consists of a cell wall on the exterior and a substance called cytoplasm on the interior.

The cell wall provides strength to the cell and helps to prevent the cell from bursting.

Animal and Plant Cells

Animal and plant cells are more complex organisms. Each of these types of cells contain a nucleus.

Animal and plant cells are called eukaryotic cells.

(“Eu” means “true” and “karyon” means “nucleus.”)

Animal cells consist of an exterior plasma membrane, and cytoplasm and a nucleus on the interior.

Plant cell structure is perhaps even more complex.

Plant cells consist of an exterior cell wall which encases a plasma membrane.

Within this, there is cytoplasm, which contains chloroplasts.

In the center, plant cells contain a space called a vacuole. Therefore, the nucleus of a plant cell is slightly off-center.

Cell structure and the plasma membrane

The plasma membrane acts as a barrier between the cell and its environment.

This membrane also controls the movement of substances into and out of the cell.

Cell structure and cytoplasm

The cytoplasm performs most of the essential “operational” functions of the cell.

Cytoplasm is present in bacterial cells, animal cells, and plant cells.

Cell Structure – Review Questions

If you are taking an exam such as the HOBET or Nursing School Entrance Exam, you should be sure that you can easily answer the following questions on cell structure.

1. Which cells are prokayyotic?
2. Which cells are eukaryotic?
3. How are plant and animal cells similar to bacterial cells?
4. How are plant and animal cells different than bacterial cells?
5. How are plant cells different than animal cells?

Answers to Cell Structure Review Questions

1. Bacterial cells are prokaryotic, meaning that they do not have a nucleus.
2. Animal and plant cells are eukaryotic. They have a nucleus.
3. All of these cells contain cytoplasm.
4. Plant and animal cells contain a nucleus, but bacterial cells do not have a nucleus.
5. Plant cells contain vacuoles and chloroplasts, but animal cells do not.