CellsParts and Functions

The Cell Theory

All organisms are made of one or more cells

The cell is the basic unit of life All cells come from pre-existing

cells

Cell Size

Types of Cells

Prokaryotic (bacteria) No membrane bound organelles Very small Can be divided into 2 groups: Eubacteria and

Archaebacteria

Eukaryotic (all other cells) Have membrane bound organelles Larger and more complex Make up 4 of the 5 kingdoms

Diagram of Cells

Focus on Eukaryotes

There are 2 different types of Eukaryotic Cells PLANT CELLS and ANIMAL CELLS Both types of cells share most of the same organelles

(“little organs” in the cell), but plant cells have: CHLOROPLASTS CELL WALLS LARGER VACUOLES A more geometric shape

Comparing Plant and Animal Cells

Parts and Functions

CELL WALL (Plants) Rigid structure made of

cellulose

CELL MEMBRANE (ALL CELLS) Semi-Permeable

membrane Controls what goes into

and out of the cell

Parts and Functions

Chloroplasts (Plants) Organelle that allows

plants to use photosynthesis to make their own food (sugar)

Contain chlorophyll – which traps energy from the sunlight

Parts and Functions

Mitochondria (Plants and Animals) The “powerhouse” of the cell Breaks down sugar to produce

energy About the size of bacteria Have their own DNA Can divide within the cell

Parts and Functions

Cytoplasm (ALL CELLS) The gel-like, water based

contents of the cell Contains and supports all

of the organelles Mostly made of water

Nucleus (Eukaryotic Cells) Contains genetic

material Controls the function of

the cell

Parts and Functions

Vacuole (Both Plants and Animals, but larger in Plants) A vesicle (membrane bound

sac) used for storage Stores water in plants and

help the plant to keep its shape

Lysosome (Mainly in Animal Cells) A very small vesicle

containing digestive enzymes

Parts and Functions

Ribosomes (ALL CELLS) Make proteins Smallest of all organelles Most numerous of all

organelles May be free floating or

located on the endoplasmic reticulum

Not covered by a membrane

Parts and Functions

Endoplasmic Reticulum: “ER” (Plants and Animals) A system of folded

membranes where many substance are made

Substance also move through the ER

It is either “rough” or “smooth” depending on if there are ribosomes on it

Parts and Functions

Golgi Apparatus (Plants and Animals) May change substance Packages materials for transport around or out of the cell