Before your Museum Visit: Cells
All living things are made of cells.
This section can serve as an introduction to your classroom study of cells or extend your investigation of cell function.
What are we made of?
Make a list of student responses. Compare this list with a comparable list made after your study of cells or use of the MathPack program.
How do we know what we are made of?
Answers can vary! Doctors or scientists can cut into bodies and look inside.
We have technology that helps us (e.g. stethoscopes, X-rays, MRI, etc.).
Teacher information:
The cell is a basic functional and structural unit of life. All living things are made of cells. All cells create copies of themselves by growing and dividing in two. Cells are so small that we need a microscope to be able to see most of them.
There are many kinds of cells but all cells contain organelles. Organelles are specialized units in the cell, each doing a different job - kind of like different parts of a city. No cell can survive without all its organelles working together.
Organelles
Nucleus: The nucleus is the biggest organelle in the cell and the center of all activity. It is where the DNA is found and replicated. It is similar to a library/city hall in a town.
Cell Membrane: The cell membrane is the sack that holds the contents of the cell. It helps protect the cell and controls what goes into and out of the cell. Both plant and animal cells have a cell membrane.
Cytoplasm: Cytoplasm is the "goo" inside the cells that the organelles float in.
Cytoskeleton: The cytoskeleton is like scaffolding. The cytoskeleton helps give the cell structure and is made of stiff proteins.
Mitochondria: The mitochondria use food that the organism eats to make energy for the cell. The mitochondria are like the power plants for the cell.
Endoplasmic reticulum: There are two types of endoplasmic reticulum - smooth and rough. The smooth endoplasmic reticulum makes fats that are then used in the cell membrane. The rough endoplasmic reticulum contains special units that make proteins.
Golgi Body: The golgi body is like a post office for the cell. It packages and sends out the proteins after they have been made in the Rough Endoplasmic Reticulum.
Lysosome: Lysosomes break down old cell parts and things that are harmful to the cell. The broken down parts are then recycled and used again in cell growth.
The next two organelles are not found on the cell at the Science Museum because it is an animal cell and these organelles are found in plant and bacteria cells.
Cell Wall: The cell wall is a stiff layer found in all plant cells and some bacteria. The cell wall surrounds and protects the cell. It is like a defense wall surrounding a city.
Chloroplast: A special plant organelle where the cell makes its food. Chloroplasts are found in all plant cells and some bacteria cells.
Color and discuss the picture of the cell with the organelles labeled.
What are some of the jobs (functions) of the parts of the cell?
Ask students what they think the different parts might do. What does a power plant do? A library? Garbage collectors? Assembly line or chemical factory?
- Provide energy for the cell and organism - humans in this case! (power plant)
- store and copy information (city hall/library)
- take care of waste (garbage collector)
- make and process chemicals for the body (proteins, fats)
This picture is a model of a cell. How wide do you think it is? (in centimeters?) Human cells are really very small. We can not see them without a microscope, so people use models to learn and teach about cells.
This image will be used at the museum to compare with a large cell model.
At the Museum Activity 1 - Measuring the Cell Model pdf
Students will also look at a tiny image of this picture under a variety of microscopes.
At the Museum Activity 3 - Microscopes pdf
Organelles are shown here to give students an idea of cells with smaller parts inside of them, if they are curious about what the parts do. The intent is not to have students memorize or know the names of the organelles or to be able to identify functions of individual organelles.
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