Unit 3Cell Structure and FunctionSection 7.1Cell Theory

1) What is a cell?

2) What does the nucleus do?

3) What is a eukaryote and prokaryote?

Discovery of the Cell1665: Robert Hooke identified

dead plant cells, and named the “cell”

1673: A. Leeuwenhoek is the 1st person to observe living cells

• Matthais Schleiden (Plants)

Theodor Schwann (Animals)

Germany 1839: all organisms made of cells.

• Rudolf Virchow (Germany 1858): all cells come from cells.

The Cell Theory

1) All living things are composed of one or more cells

2) Cells are the basic unit of structure and function in organisms

3) All cells come from the reproduction for pre-existing cells

Cell DiversityAll cells have different shapes,

sizes, and functionsThe size and shape of a cell will

relate to its ___________

Cell DiversitySize:

◦Cells are limited by their outer surface area and volume

Shape:◦The shape relates to the cell function

Nerve cells

Red and White Blood Cells

Cell DiversityInternal Organization:

◦Organelle: cell components that performs ____________ for the cell Will maintain life for the cell

◦Cell is surrounded by a ___________ Each organelle has its own membrane

◦Nucleus:

Cell DiversityEukaryotes: organisms that contain a

membrane-bound nucleus and organelles◦ Animal cells

Prokaryotes: unicellular organisms that lack membrane-bound nucleus and organelles◦ bacteria

Prokaryotic Cell

Cell membrane

Cell membrane

Cytoplasm

Cytoplasm

Nucleus

Organelles

Eukaryotic Cell

Compare and Contrast the Eukaryotic and Prokaryotic Cell

Eukaryote and Prokaryote

BACTERIA MAGNIFIED

Bacteria on the tip of a pin