Cells. The Cell Theory. But what is a cell? Contributors to the Cell Theory:

Size: px

Start display at page:

Download "Cells. The Cell Theory. But what is a cell? Contributors to the Cell Theory:"

Moses Hoover
5 years ago
Views:

Cells "Long ago it became evident that the key to every biological problem must finally be sought in the cell; for every living organism is, or at some time, has been a cell." E.B.

1 Cells "Long ago it became evident that the key to every biological problem must finally be sought in the cell; for every living organism is, or at some time, has been a cell." E.B. Wilson The Cell Theory The cell theory united plant and animal sciences by recognizing that the cell is the fundamental component of all living organisms, from orchids and earthworms to human beings. 2 But what is a cell? Contributors to the Cell Theory: An enclosure Boundary Interior region Hereditary store Robert Hooke (named cells) Anton Van Leeuwenhoek (saw microorganisms) Robert Brown (discovered the nucleus) Matthias Schleiden (plants are made of cells) Theodor Schwann (animals are made of cells) Rudolf Virchow (cells come from cells) 3 4 1

Robert Hooke 1635~1703 In 1665 The first person to see and name cells.

Anton van Leeuwenhoek (1632~1723) Investigated the natural world using experimental methods supported by the evidence of the senses.

2 Robert Hooke 1635~1703 In 1665 The first person to see and name cells. He examined (dead) cork bark with a primitive microscope Saw little cubicles which he called cells (cell = room, cubicle). Anton van Leeuwenhoek (1632~1723) Investigated the natural world using experimental methods supported by the evidence of the senses. He made with his own hand certain most excellent lenses He invented the microscope 5 6 And saw wondrous creatures Robert Brown Spirogyra described by Leeuwenhoek "Passing just lately over this lake,... and examining this water next day, I found floating therein divers earthy particles, and some green streaks, spirally wound serpent-wise, and orderly arranged, after the manner of the copper or tin worms, which distillers use to cool their liquors as they distil over. The whole circumference of each of these streaks was about the thickness of a hair of one's head... all consisted of very small green globules joined together: and there were very many small green globules as well." Robert Brown reported the existence of nucleus in

Matthias Jacob Schleiden (solicitor & botanist 1804 ~ 1881). Founder of the cell theory. Plants were aggregates of "fully individualized, independent, separate being, namely the cells themselves.

3 Matthias Jacob Schleiden (solicitor & botanist 1804 ~ 1881). Founder of the cell theory. Plants were aggregates of "fully individualized, independent, separate being, namely the cells themselves." Author of Basic Scientific Botany, the definitive textbook on botany at the middle of the 19 th century. Promoted commercial production of microscopes Theodor Schwann ( ). Noticed nucleated units in animal tissue. After discussions with Schleiden concluded that animals were composed of cells. Did experiments that challenged Spontaneous Generation Rudolf Virchow pathologist (1858) Omnis cellula e cellula" (where a cell arises, there a cell must previously have existed). First to state the cell theory: "Every animal appears as a sum of vital units, each of which bears in itself the complete characteristics of life." The Cell Theory All living things are composed of cells and cell products. The cell is the smallest unit of life. Living creatures come from the growth and division of single cells

4 Cells Come in Different Shapes Nostoc and Amoeba and Neurons Cells Come in Different Sizes Diatom & Mouse Hair

5 Ostrich eggs are the biggest cells. Most cells can only be seen with a microscope Microscopes: Basic Cell Types Types of Microscopes Light Microscope Phase~Contrast Microscope Scanning Electron Microscope Transmission Electron Microscope Prokaryotic Simple Structure Small Cell Membrane Cytoplasm Ribosomes NO ORGANELLES Naked DNA Eukaryotic Complex Structure Small to Large Cell Membrane Cytoplasm Ribosomes on membranes Membrane-Bound Organelles Nucleus contains DNA

Eubacteria 21 22 More Eubacteria A Basic Eukaryotic Cell Note

6 Prokaryotic Cells Prokaryotic Cells Simple Structure: Membrane, Cytoplasm, Ribosomes, and Naked DNA Archeabacteria Cyanobacteria Eubacteria More Eubacteria A Basic Eukaryotic Cell Note the complex inner structure Lactobacillus Nitrosomas E. coli

7 Eukaryotic Cell Sperm and Eggs Amoeba Amorphous shape & pseudopods Small Motile Cells Large Sessile Cells Red Blood Cells Plant and Animal Cells Small cells without a nucleus. Filled with hemoglobin for oxygen transport throughout the body Cell Membrane Cell Membrane &Cell Wall

8 Cell Membrane Cytoplasm The fluid mosaic model: Phospholipids with embedded proteins. Cell substance Filled with solids,liquids, organelles, cytoskeletal support fibers & inner network of membranes Nucleus Mitochondria The Nucleus: Control Center of the Cell Cell Powerhouse: Site of Cellular Respiration C 6 H 12 O 6 + O 2? CO 2 + H 2 O

9 Endoplasmic Reticulum Golgi Apparatus Rough & Smooth Endoplasmic Reticulum Protein Synthesis Lipid Synthesis A system of sacs and vesicles in the cytoplasm Chloroplasts Central Vacuole Chloroplasts : Site of Photosynthesis CO 2 + H 2 O? C 6 H 12 O 6 + O 2 Characteristic of a Plant Cell

10 Cytoskeleton Flagella & Cilia Trypanosome Rat Smooth Muscle Cells: Actin & Myosin Trypanosome Euglena Tracheal Cells Sources ek.html ctures/history_of_biology.htm htm

Discovery of the Cell

Cell Structure Discovery of the Cell Who discovered cells? 1665 Robert Hooke used a compound microscope to examine a piece of cork (20X magnification) He saw little boxes in the cork and called them cells