A View of the Cell Life is Cellular

Discovering the Cell Robert Hooke used a microscope to study cork coined the term “cell” Before microscopes were invented, people believed that diseases were caused by curses and supernatural spirits. Invention of the microscope - scientists realized they were entering a new world – one of microorganisms. Microscopes enabled scientists to view and study cells, the basic units of living organisms. Hooke – cork- thousands of tiny,empty chambers (monastery’s chambers called cells) Cells are not empty! Around the same time, Van Leuenhoek – tiny living organisms everywhere, even in the water he drank! Schleiden concluded that all plants are made up of cells Schwann concluded that all animals are made of cells. Lead to the cell theory. . . Anton van Leeuwenhoek first person to discovered life in water using a microscope

I. Introduction to the Cell A. Cell Theory All organisms are made up of one or more cells. Cells are the basic unit of structure & function in organisms. All cells come from preexisting cells. All living things are composed of cells. Cells are the basic unit of structure & function in living things. New cells are produced from existing cells.

B. Cells differ in size, shape, & organization. Cell Size Small cells function more efficiently than large cells. Smaller is BETTER! Large cells cannot function efficiently in the transport of materials & waste into and out of the cell.

B. Cells differ in size, shape, & organization. Cell Shape The shape of cell depends on its function.

C. Internal Organization Most cells contain a variety of membrane bound ORGANELLES - cell parts that perform specific functions for the cell Organelles – little organs

A Large Organelle near the center of the cell is the NUCLEUS A Large Organelle near the center of the cell is the NUCLEUS.  It contains the cell’s genetic information and controls the activities of the cell. Whether a cell has or does not have a NUCLEUS is important for classifying cells.

II. Prokaryotes Vs. Eukaryotes ORGANISMS WHOSE CELL OR CELLS CONTAIN A NUCLEUS AND OTHER MEMBRANE-BOUND ORGANELLES. MORE COMPLEX CAN BE HIGHLY SPECIALIZED UNICELLULAR OR MULTICELLULAR PLANTS, ANIMALS, FUNGI, PROTISTS

Prokaryotes Vs. Eukaryotes ORGANISMS WHOSE CELLS DO NOT HAVE A NUCLEUS AND OTHER MEMBRANE-BOUND ORGANELLES. SMALLER AND SIMPLER UNICELLULAR ORGANISMS SUCH AS BACTERIA AND BLUE-GREEN ALGAE

The difference between Prokaryotes and Eukaryotes is such an important distinction that they are placed in separate Kingdoms.

Cell Structure (concept map) can be prokaryotic eukaryotic which are found in animals which are known as which lack which contain plants protists fungi bacteria organelles

WRAP-UP QUESTIONS What is the smallest most basic unit of life? Where is DNA in eukaryotes? …prokaryotes? Why would you need a microscope to see a prokaryotic organism? What are the 3 parts of the cell theory? Where do viruses fit in the cell theory?

Virology - study of viruses tiny, much smaller than a cell and only visible with advanced electron microscopes;

Viral Characteristics Non living Not made up of cells Cannot grow or replicate on their own Must be reproduced in living cells