Living cells are made up of a system of parts that work together to perform a variety of functions. Students looking at pictures of cells in textbooks may have the impression that cells are flat, static, 2-dimensional objects. Building a model of a cell helps students understand the 3-D nature of cells, and reinforces what they learn about the shape, size and function of each of the parts within a cell.
The Cell Model Base
A three-dimensional cell model starts with a base. The base represents the cell cytoplasm, the gel-like contents within a cell that are surrounded by the cell membrane. Animal cell models are generally depicted as round, oval or spherical in shape. The base of a plant cell model is generally given a rectangular shape.
Plant and Animal Cell Organelles
A three-dimensional model of a cell must also include several specialised parts of a cell known as the cell organelles. Organelles common to both plant and animal cells include the nucleolus, nucleus, vacuole, rough endoplasmic reticulum, smooth endoplasmic reticulum, golgi apparatus, ribosomes and mitochondria. Organelles unique to plant cells include the cell wall and chloroplasts. Organelles unique to animals cells include the lysosomes and centrioles.
The styrofoam Model
You will need a large styrofoam craft ball, or a rectangle of styrofoam. If using a large styrofoam ball, cut it in half. Hollow out a space in the styrofoam and place a small ball inside to represent the nucleus of the cell. Glue other items, like buttons, pipe cleaners, yarn, tacks and paper clips to the cell base to represent the cell organelles. If you are creating a plant cell, wrap aluminium foil around the outer edge of the cell base to represent the cell membrane.
The Glass Jar
Use a clear glass jar to represent the cell membrane. Place objects within the jar to represent the cell organelles. For example, a golf ball may be used as the nucleus. Thick rubber bands could represent the endoplasmic reticulum. Dried beans could be used for the mitochondria. Fill the jar with baby oil, corn syrup or vegetable oil to represent the cell's cytoplasm. Place a lid on the jar. Shake the jar whenever the items settle on the bottom.
Project Idea: Gelatin Mold
Create an edible cell model with lemon gelatin. Prepare the gelatin according to package instructions, but use a little less water so the gelatin will be stiff. Pour the prepared gelatin into a clear glass bowl or pan. The glass container will represent the cell wall or cell membrane. Allow the gelatin to cool until it has partially thickened. Stir in the rest of the parts of the cell, such as a large marshmallow for a nucleus. Gummy worms, jelly beans, gum drops, liquorice vines, small marshmallows, pieces of fruit, nuts and other edible items can be used to represent the rest of the organelles.
More Project Ideas
Three-dimensional cell models can be made by decorating a cake with icing organelles, or building a cell with play dough or modelling clay. Both methods have the benefit of being able to simply shape the icing or clay into the required parts of the cell, without having to look for items that resemble those parts.