Chapter 4.1 Introduction to the cell

Robert Hooke 1665 used a microscope to examine a piece of cork. (dead cells) He described it as consisting of “a great many little boxes”. These “little boxes” reminded him of the small rooms in which monks lived, so he called them cells

Anton van Leeuwenhoek 1674 First person to observe living cells (single-celled organisms in pond water) Dutch microscope maker

Matthias Schleiden 1838 German botanist Concluded that all plants are made of cells

Theodor Schwann 1839 German scientist Concluded that all animals are made up of cells

Rudolf Virchow 1855 German physician Proposed that all cells come from existing cells

Janet Plowe 1931 demonstrated that the cell membrane is a physical structure, not just an interface between two liquids

Lynn Margulis 1970 Proposed the theory that certain organelles were once free-living cells themselves Theory:  ENDOSYMBIOSIS

The Cell Theory 3 parts of the theory: 1. All living things are composed of 1 or more cells 2. Cells are the basic units of structure & function in an organism 3. Cells come only from the reproduction of existing cells

PLANT CELL!

ANIMAL CELL!

Cell Diversity Your body contains at least 200 different cell types.

Size of cells Cells are limited inside by the ratio between their outer surface area and their volume

Why don't we get Giant Cells?

Internal Organization Organelles- a cell component that performs specific functions for the cell.

Cell Membrane Cell membrane- thin membrane surrounding the cell

Prokaryotes Lack a membrane-bound nucleus Example: all bacteria

Eukaryotes Has a nucleus & organelles Examples: plant and animal cells