You will compare animal and plant cells by analyzing the organelles they have in common and organelles that are unique to each.
After completing this tutorial, you will be able to complete the following:
Plant and animal cells can vary widely in form and function; however, they have many of the most important cell structures in common. Both plant and animal cells have a nucleus, which contains the cell's genetic material. Plant and animal cells also have some of the same organelles floating in the cytoplasm, the fluid-filled region between the cell membrane and the nucleus. In both plant and animal cells, mitochondria, the cell's "powerhouses," convert energy in nutrients into useable energy through the process of aerobic respiration. Ribosomes are responsible for synthesizing proteins. The endoplasmic reticulum stores and transports proteins and other compounds within the cell. The Golgi apparatus transforms proteins into more complex molecules and lysosomes contain enzymes used to break down large molecules and wastes. Both plant and animal cells are also surrounded by a cell membrane that is semi-permeable and allows for the movement of materials into and out of cells.
Plant cells and animal cells differ in several important ways. Plant cells have structures called chloroplasts. Chloroplasts are the structures that give leaves their green color and, more importantly, allow plants to acquire their energy from the Sun rather than from food, which is the primary source of energy for animals. Like mitochondria, chloroplasts convert energy from one form to another. This process is called photosynthesis. In aerobic respiration within mitochondria, food molecules are combined with oxygen to produce energy and carbon dioxide. In photosynthesis, chloroplasts use energy from the Sun to convert carbon dioxide and water into food molecules like sugars and other carbohydrates.
Unlike animal cells, plant cells have a cell wall that surrounds the entire cell, including the membrane. The cell wall provides plant cells with a protective covering and gives the plant the rigidity it needs in order to stand up even under pressure from wind, rain, and snow. This wall is made of cellulose and is intricately cross-linked with fibers of other carbohydrate molecules. This structural pattern also allows each cell to withstand the increased internal pressure, known as turgor pressure, when the plant absorbs water.
Another structure that helps plants retain turgor pressure by storing a lot of water is a large central plant vacuole. Animal cells have vacuoles also, however, animal vacuoles are much smaller. Both plant and animal vacuoles serve as storage areas for water, nutrients, and wastes.
There are two other organelles that have a more pronounced function in animal cells than in plant cells. Lysosomes digest wastes and worn out organelles in animal cells. Centrosomes are organelles located near the nucleus in the cytoplasm that play a role in cell division, or mitosis. They usually contain two centrioles that migrate to opposite poles of the cell during cell division and form spindle fibers that guide the chromosomes during this process.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Students should be familiar with the cell and the cell theory.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||animal cell, animal vacuole, cell membrane, cell wall|