Cells

Cells• All living things are made of cells

• All cells come from preexisting cells

• Cells are the basic structural and functional unit of life (Cell Theory)

Structure and Function• A cell’s structure (shape and size) is directly related to its function

• Skin cells are “plate like”• Nerve cells are long and branchy

Cell Size• Cells are relatively small because they must maintain a high surface area (cell membrane) to volume (cytoplasm) ratio

• If a cell gets too large it will STARVE

Prokaryotes• Prokaryotes are organisms whose cells lack a “true” nucleus

• These cells are usually small and simple

• Example: Bacteria

Eukaryotes• Eukaryotes are organisms whose cells contain a “true” nucleus

• These cells are usually large and complex

• Examples: Plants, Animals, Fungi, Protists

Plant vs. Animal Cells• Plant cells have:

– A Cell Wall (used for structure)– A Central Vacuole (used to maintain turgor pressure)

– And Chloroplasts (needed for photosynthesis)

Pulse Check• Now that you know so much about cells, try your hand at illustrating each of the following types of cells:– Prokaryotic– Eukaryotic: Animal and Plant