Cells & Life Chapter 2 Lesson 1

cytology: the study of cells Robert Hooke Anton van Leeuvenhoek Matthias Schleiden Theodor Schwann Rudolf Virchow

Robert Hooke Cytology can be traced back over 300 years to the English scientist Robert Hooke.

Robert Hooke In 1665 he published Micrographia - a report of his use of simple compound microscopes capable of magnifying approximately 30 times to observe cork.

Robert Hooke The neat rows of little boxes reminded him of rows in a prison or a monastery - he therefore named the "cells." (“coined”)

Robert Hooke In 1665 Robert Hooke was the first to use the term cell. He saw only the dead, empty walls of cork cells.

Anton van Leeuwenhoek Around the same time as Robert Hooke, Anton van Leeuwenhoek also began to observe tiny objects with microscopes.

Anton van Leeuwenhoek He looked at drops of lake water, scrapings from teeth and gums, and water from rain gutters.

Anton van Leeuwenhoek He saw tiny moving organisms which he called “animalcules,” meaning “little animals.”

"All plants are composed of cells." Matthias Schleiden A German botanist In 1838 said, "All plants are composed of cells."

"All animals are composed of cells." Theodor Schwann A German zoologist In 1839 said, "All animals are composed of cells."

A German doctor who is referred to as the "Father of Pathology," Rudolf Virchow A German doctor who is referred to as the "Father of Pathology," In 1855 he proposed that new cells are formed only from cells that already exist.

The three basic principles of the cell theory All living things are made of one or more cells. The cell is the smallest unit of life. All cells come from preexisting cells.

Understanding cells How did scientists’ understanding of cells develop?

Basic Cell Substances The main ingredient in any cell is water. A water molecule has two areas: The negative (–) end can attract the positive part of another substance. The positive (+) end can attract the negative part of another substance.

Basic Cell Substances Water and salt both have positive and negative parts.

Basic Cell Substances Macromolecules are necessary substances in cells, formed by joining many small molecules together. macromolecule from Greek makro–, means “long”; and Latin molecula, means “mass”

Basic Cell Substances There are four types of macromolecules in cells: Nucleic acids are macromolecules that form when long chains of molecules called nucleotides join together. Two types: DNA & RNA Proteins are long chains of amino acid molecules. Proteins are involved in almost everything that happens in a living cell.

Basic Cell Substances These are essential molecules of life! Lipids are large macromolecules that do not dissolve in water. Carbohydrates store energy, provide structural support, and are needed for communication between cells. Made of CHO. Examples: sugar & starch These are essential molecules of life!

Each type of macromolecule has unique functions in the cell.