Overview
In this activity, students explore the relationship between structure
and function in a cell. They start by viewing a variety of specialized
cells. They learn the three main parts of a cell -- the nucleus,
cytoplasm, and cell membrane -- and discuss generally what each part
does. Then, through a Web activity, they explore the gatekeeper role
of the cell membrane. They follow up by examining in more detail the
organelles located in the cytoplasm. Next, students compare animal and
plant cells. Finally, they explore the similarities and differences
among specialized cells.
Objectives
- Recognize the relationship between structure and function
in a cell
- Explore the role of the cell membrane
- Explore the role of organelles
- Compare animal and plant cells
- Compare the structure and function of specialized cells
Suggested Time
Multimedia Resources
Materials
- Unlined 3 in. x 5 in. index cards (3-4 per student)
for cell drawings
After the Lesson
- Have students explore a variety of plant and animal
cells under a microscope and identify the cell structures described
in this lesson. Have students measure cells to compare sizes.
The Lesson
Part I
1.
Have students explore the
Gallery of Cells
stills to see the variety of specialized cells that exist
in organisms. Then show the
Nucleus, Cytoplasm, Membrane video and discuss
the following:
- How does the structure of a cell suggest its function?
- In what way does the nucleus dictate the structure
and function of the cell?
- How does the cell membrane act as the
"gatekeeper" for the cell?
2.
Have students explore the
Cell Membrane: Just Passing Through
Web activity. Discuss the following:
- How does the composition of the cell membrane help regulate
the movement of substances into and out of the cell?
- Describe the different processes involved in the movement
of these substances into and out of the cell: oxygen,
carbon dioxide, glucose, potassium, sodium, water,
and enzymes.
3.
Show the Organelles in the Cytoplasm video.
Ask:
- What is meant by the phrase "the cell is the
functional unit of life"?
- How are the organelles in a cell like the organs
in a human body?
- Why do you think cells that produce large numbers
of proteins have more rough endoplasmic reticulum (ER) than
cells that produce fewer proteins?
- In which kinds of human cells would you expect to
find the most mitochondria? The most lysosomes?
The most ribosomes? Explain your answers.
4.
Have students examine the
Animal and Plant Cell stills
and identify the similarities and differences between the
two types of cells. Ask:
- What is the most significant difference between
animal and plant cells? Why do you think that?
5.
Have students explore the
Gallery of Cells
stills again, this time looking for similarities and
differences in the cells. Ask them to draw at least
three different types of specialized cells on separate
index cards and to label the cell type (animal or
plant) and any recognizable cell structures.
Then have students compare the different cells and describe
how their structures are related to their functions.
