Functions of Cells

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.

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.

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

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

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

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

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

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

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.

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.

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

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.

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

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

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?)

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.

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.

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.

The Answers

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

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

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

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