1. Functions of Cells

2. Things to Know
The shape and size of a cell are related to its function.
What does that mean?
The shape of the cell helps it perform its task.

3. For Example
What are do plant cells have around them that animal cells don’t?
Cell Wall
What is the shape of the cell wall?
Close together
What task (function) does the cell wall perform?
protects the cell
How does the shape relate to the function?
The cell wall fits tightly to protect the cell.

4. Skin Cells
How does the shape of skin cells help the cells do their task?
Cover and protect your body

5. Nerve Cells How does the shape of nerve cells help the cells function?
long, narrow - so that it can carry messages to many cells

6. Blood Cells How does the shape of blood cells help the cells function?
bowl shape - so they can easily travel through the veins.

7. Muscle Cells
How does the shape of muscle cells help the cells function?
long and thin - allows them to contract

8. White blood cells Link Job: find and destroy invaders Shape: irregular
How does their shape help them do their job?
allows them to slip through the thin walls of blood vessels and move among your muscle cells and other tissues

9. One-Celled Organism
Must carry out the same jobs that are carried out by many celled organisms!
Their different shapes help them survive
The following slides will introduce you to some single-celled organisms

10. Vorticella Lives in ponds and attaches to solid objects such as twigs
It is funnel shaped
It has small hair-like structures called cilia which beat near the funnel. This creates a whirlpool.
What do you think happens then?
food particles are swept into the funnel and eaten by the vorticella.

11. Ameba lives on the bottom of bodies of water has no definite shape
moves by pushing out its cytoplasm into thin pouches in the cell membrane called pseudopods
the pseudopod surrounds the food and the ameba digests it.

12. Cells Vary
Cells vary in size and shape. Does that mean that larger animals have larger cells?
not always
Cells do come in many shapes and sizes, but bodies grow bigger by having MORE cells, not bigger cells.
The largest single cell is and ostrich egg.
The smallest cell is bacteria

13. Other Differences
The function (task or job) determines the kind of organelles it has, and the number of organelles it has.
What is an organelle again?
tiny structure in cytoplasm that performs a special job.
What are some examples of organelles?
nucleus, mitochondria, vacuole, etc.

14. Muscle Cells Must contract quickly as you stand, walk, and run
It contains more energy-producing mitochondria than other cells

15. Heart Cells or Skin Cells
Which would have more mitochondria?
heart cells, because they are always active

16. Special outgrowths
Some cells have pieces growing out of them to help them function.
Flagella extend from the volvox and help them move
The Vorticella has hairlike structures called cilia at the top of its funnel. (Remember?)

17. Special outgrowths
The cells that line your breathing passage, lungs, and nose have hundreds of cilia to keep your air passages clean.
The paramecium have cilia to help it move in the water.

18. Quiz - True or False
A cell’s shape helps it perform its specific function.
The job of white blood cells is to find and destroy bacteria
All one-celled organisms are similar to one another.
An ameba moves by pushing out cytoplasm into pouches called pseudopods.

19. Quiz - True or False
As you grow taller, your individual cells grow bigger.
Heart cells that beat constantly have more mitochondria.
Cilia are extensions of animal cells that move rapidly.
All cilia are used to help animal cells find food.
All animal cells have the same number of organelles.

20. The Answers

21. Quiz - True or False
A cell’s shape helps it perform its specific function. True
The job of white blood cells is to find and destroy bacteria True
All one-celled organisms are similar to one another. False
An ameba moves by pushing out cytoplasm into pouches called pseudopods. True

22. Quiz - True or False
As you grow taller, your individual cells grow bigger. False
Heart cells that beat constantly have more mitochondria. True
Cilia are extensions of animal cells that move rapidly. True
All cilia are used to help animal cells find food. False
All animal cells have the same number of organelles. False

23. Activity
Write a script for a skit in which a person interviews different kinds of cells about their:
size & shape
functions they perform
Why the size & shape helps their function
Each person in the skit must say something
You will hand in your group script

24. Kinds of cells you could use
different human body cells:
muscle, nerve, blood, heart, skin, etc.
plant cells
single-celled organisms:
vorticella, ameba, volvox, bacteria, paramecium