Differences Between Plant and Animal Cells

Differences Between

Animal Cells and Plant Cells

By D.J. Paulson

Background Informaton:

Structurally , plant and animal cells are very similar because they are both eukaryotic. Both plant and animal cells contain membrane-bound organelles such as the nucleus, mitochondria, golgi complex, and endoplasmic reticulum. Both also contain similar plasma membranes and cytoskeletons. The functions of these organelles are extremely similar. However, the few differences that exist between plant and animals are very significant and reflect a difference in the functions of each cell. Let's explore! First complete a venn diagram as a prelearning activity to assess prior knowledge! Then click on Monty to hear his question!

Centrioles

Every animal cell has two small organelles called centrioles. Centrioles help the cell divide during the processes of mitosis and meiosis. Centrioles are composed of microtubules and they can usually be found near the nucleus. The centrioles are always found in pairs but separate as they move towards the poles (opposite ends) of the cell prior to cell division. During division, you may also see groups of threads attached to both the centrioles and chromosomes. Those threads are called the mitotic spindle. 

Cell Wall

While cell membranes might be around every cell, cell walls (made of cellulose) are only found around plant cells. Cell walls are made of specialized sugars called cellulose. The cell wall protects the plant cell and also helps plants keep their shape by providing a sturdy and protected framework for a plant cell. Picture taking a water balloon and putting it in a cardboard box. The balloon is protected from the outside world. For these reasons cellulose is called a structural carbohydrate.

Vacuoles

Vacuoles are the storage compartments of a cell. While they can be found in both animal and plant cells, they are much larger in plant cells. Vacuoles can store nutrients or waste products until a time when they can be sent out of the cell. 

In plant cells, the vacuole is much larger than in animal cells. When a plant cell has stopped growing, there is usually one very large vacuole. That vacuole can take up more than half of the cell's volume. 

Helping with Support

Vacuoles also play an important role in plant structure. Plants use cell walls to provide support and surround cells. The size of that cell may still increase or decrease depending on how much water is present. Plant cells do not shrink because of changes in the amount of cytoplasm . Most of a plant cell's volume depends on the material in vacuoles.

Those vacuoles gain and lose water depending on how much water is available to the plant. A drooping plant has lost much of its water and the vacuoles are shrinking. It still maintains its basic structure because of the cell walls. When the plant finds a new source of water, the vacuoles are refilled and the plant regains its structure. 

Chloroplasts

Chloroplasts are specialized organelles found in all plant cells. These organelles contain the pigment chlorophyll which is responsible for the plant's green color and its' ability to absorb energy from sunlight. Plants use this energy to convert water and carbon dioxide into simple sugars and oxygen. This process is called photosynthesis . 

Sources:

http://www.thefreedictionary.com/

http://www.cellsalive.com/cells/chloropl.htm

http://www.biology4kids.com/files/cell_main.html

Illustrations from:

1. http://www.pics4learning.com/
2. Pictures of student cell projects taken by D.J. Paulson and constructed by students in his 2013 Living Envrionment Regents classess.  
3. Pictures taken using a microcope camera while observing red onion cells and elodea cells.