Cells

Cells

What is a cell?

What’s inside a cell?

What are the differences between animal cells and plant cells.

What is a cell?• A cell is the smallest unit that is capable of

performing life functions.

• The cells theory states the following:– All living things are made up of cells. – All cells come from preexisting cells through

cell division. Red Blood Cells

Onion CellsCheek (Skin) Cells

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

What is inside a cell?• Cells are made up of

parts called organelles or “little organs”.

• The parts of a cell that we are going to discuss include:– Cell Membrane– Cell Wall– Nucleus– Cytoplasm– Chloroplasts– Vacuoles– Mitochondria

• Some organelles are only found in plant cells. – These include cell walls

and chloroplasts.– The vacuoles found in

plant cells are larger.

Cell Membrane

• Surrounds a cell, allows certain materials to enter the cell and waste products to exit

• Outer membrane of cell that controls movement in and out of the cell

• Double layer

http://library.thinkquest.org/12413/structures.html

Cell Wall

• Tough material surrounding the cell membrane in plant cells.

• Most commonly found in plant cells & bacteria

• Supports & protects cells

http://library.thinkquest.org/12413/structures.html

Nucleus • Directs cell activities

• Separated from cytoplasm by nuclear membrane

• Contains genetic material - DNA

Cytoplasm

• All the material of the cell between the cell membrane and the nucleus

• Gel-like mixture

• Surrounded by cell

membrane

• Contains hereditary

material

Mitochondria

• The cell’s power producers.

• Mitochondria combine oxygen and food to produce energy in the process of cellular respiration.

• Controls level of water and other materials in cell

http://library.thinkquest.org/12413/structures.html

Vacuoles

• Membrane-bound sacs for storage, digestion, and waste removal

• Contains water solution

• Larger in plant cells• Help plants maintain

shape by storing water

http://library.thinkquest.org/12413/structures.html

Chloroplast

• Uses the energy in sunlight to turn water and carbon dioxide into sugar and oxygen (a process called photosynthesis)

• Usually found in plant cells

• Contains green chlorophyll

http://library.thinkquest.org/12413/structures.html

What are the differences between plant and animal cells?

• Plant cells are much like animal cells, except for 3 important differences.– Plant cells have cell walls, which make them appear

rectangular-shaped.  These structures are composed of cellulose, hemicellulose, and a variety of other materials.

– Plant cells have chlorophyll, the light-absorbing pigment required for photosynthesis.  This pigment is contained in structures called chloroplasts, which makes plants appear green.

– Plants cells have a large, central vacuole.  While animal cells may have one or more small vacuoles, they do not take up the volume that the central vacuole does (up to 90% of the entire cell volume!).  The vacuole stores water and ions, and may be used for storage of toxins.

Plant Cell vs Animal Cell

What am I, plant or animal?

Plant Cell Animal Cell

Pictures of cells

Cancer cell being attacked by the immune system

Cheek (Skin) Cells

Nerve Cells

Liver Cells

A plant cell from the leaf 

of a poplar tree

Seaweed under a microscopePlant cell with nucleus very visible

Stomach Cells

Muscle Cells

Bone Cells

Cardiac Muscle (Heart) Cells

Very thin slice of plant skin

Orchid (flower) cellsLeaf Cells of Moss

Cells in a

plant root

Credit Slide

• Pictures were found via yahoo image search.

• Some information was found via yahoo search.

• Some information was retrieved from Science-Class.net