Chapter 4 Cell Structure and Function

Review: Early scientists that led to the cell theory –Anton van Leeuwenhoek (1600s) – given credit for developing the 1st mini microscope, looked at pond water and made detailed drawings –Robert Hooke – coined the term “cell” when he looked at slices of cork and dead plant cells –Robert Brown (1833) – observed a dark structure near the center of the cell (we now know this is the nucleus) –Matthias Schleiden (1838) – stated all plants are made of cells –Theodor Schwann (1839) – discovered all animals are made of cells –Rudolph Virchow (1855) - stated all cells come from the division of preexisting cells

Cell Theory –All living things are composed of cells. –Cells are the basic units of structure and function in living things. –All cells come from preexisting cells.

Introduction to Cells –Shape Diversity of shape reflects diversity of functions Can be simple or complex depending on its function Cell shape evolved to allow the cell to perform its function effectively

–Size Most range from 10 to 50 µm Limited by the relationship of the cell’s outer surface area to its volume

Basic Parts of the Cell Plasma Membrane Cytoplasm Material between the cell membrane and the nucleus Contains the organelles of the cell Control Center Prokaryote vs. eukaryote

2 categories of organisms –Prokaryotes – organisms whose cells lack nuclei (i.e. bacteria) –Eukaryotes – organism whose cells contain nuclei Pro- = before Eu- = true -karyon = kernel/nucleus Prokaryote vs. Eukaryote

CharacteristicProkaryoticEukaryotic Cell membrane Cytoplasm Genetic Material Nucleus Organelles (only ribosomes) Archaea Bacteria Plants, animals, fungi, & protists

Organelle - Well-defined, intracellular bodies that perform specific functions for the cell. flagellum cell wall cell membrane ribosome DNA pili