CELL THEORY HISTORY ROBERT HOOKE ● He discovered and coined the term “cells” from a piece of dead cork ANTOINE VAN LEEUWENHOEK ● He observed the first living cells through a one lens simple microscope ● He went on to be the first to observe and describe spermatozoa in 1677. MATTIAS SCHLEIDEN ● He discovered that plants are composed of cells THEODOR SCHWAN ● He discovered that animals are composed of cells RUDOLPH VIRCHOW ● He stated that “all living things are made up of cells” and these cells are made from other living cells. ● He collaborated with Schwann and Schleiden about his observation to develop the cell theory CELL THEORY CONCEPTS ● ● ● All organisms are made of one or more cells. All the life functions of organisms occur within cells. All cells come from already existing cells. CELL AND CELL STRUCTURE ● ● ● ● ● building blocks of life smallest living unit of an organism They grow, reproduce, use energy, adapt, respond to their environment A cell may be an entire organism or it may be one of billions of cells that make up the organism One common classification method is the presence or absence of a cell nucleus ○ Prokaryotes – have no nucleus ○ Eukaryotes – have a nucleus 1. The plasma membrane is a thin coat of phospholipids that surrounds a cell. It forms the physical boundary between the cell and its environment. 2. Cytoplasm refers to all of the cellular material inside the plasma membrane. The Cytoplasm is made up of cytosol and contains other cell structures such as ribosomes. 3. Ribosomes are structures in the cytoplasm where proteins are made.