1. Cell Structure and Function Chapter 4

2. The history of cell biology Both living and nonliving things are made of atoms, molecules and compounds. How are living and nonliving things different?

3. Discovery of cells All living things are made up of one or cells. Cell- smallest unit that can carry on all of the processes of life.

4. Robert Hooke English Scientist Used an early light microscope to study nature in 1665. Light Microscope- uses optical lenses to magnify objects by bending light rays. He named them cells after looking at a cork and noticing that the it looked like the “cells” where monks live.

6. Anton van Leeuwenhoek Dutch Trader 1 st person to observe living cells Made microscopes with a lens 10 times the magnification of Hooke’s. Looked at Spirogyra…..called them animalcules….now called protists.

8. Cell Theory The importance of these discoveries were not realized until 150 years later. In 1838, German botanist, Matthias Schleiden concluded that all plants were composed of cells. The next year German zoologist, Theodore Schwann concluded the same thing for animals.

9. German physician, Rudolf Virchow noted that all cells come from other cells. These observations were combined to form the CELL THEORY!

10. The Cell Theory All living organisms are composed of one or more cells Cells are the basic units of structure and function in an organism Cells come only from the reproduction of existing cells

11. Time Line of Cell Biology 1665- Robert Hooke observes cork cells 1827- mammalian egg discovered 1855- Virchow adds to the cell theory 1897- Golgi apparatus discovered 1996- Sheep cloned from an adult sheep cell 2004- Tissue engineering used to grow new skin and bone for transplant

12. Cellular basis of life Microscopes helped biologists clarify our definition of life. All living things share several basic characteristics of life.

13. Basic Characteristics Organized parts Obtain energy from their surroundings Perform chemical reactions Change with time Respond to their environment Reproduce

14. homeostasis The ability to maintain a constant internal environment.

15. Cell Diversity Cells are very diverse in shape, size, and internal organization. Cells function influences its physical features

16. Cell Shape The diversity of cell shapes reflects the different function of cells. It can be simple or complex.

17. Cell size Some cells can be seen with the naked eye. Most cells however are only 10 to 50 micrometers in diameter. (1/500 the size of the period at the end of a sentence.)

18. Basic parts of a cell Plasma Membrane- (cell membrane)- covers a cell surface and acts as a barrier between the inside and the outside of the cell. Cytoplasm- region inside the plasma membrane that includes the fluid, cytoskeleton, and all the organelles except the nucleus. Nucleus- Membrane bound organelles that contains DNA.

19. Types of Cells Prokaryotes- lack membrane bound organelles, and have no nucleus. DNA gathers in a central location call the nucleoid. 2 domains- Bacteria and Archea Eukaryotes- made up of one or more cells that have a nucleus and membrane bound organelles. Organelles- well defined intracellular bodies that perform specific functions in a cell.

20. Cellular Organization Over time cells begin to form groups that functioned together. Some cells retained the ability to live outside a group. Others need each other to survive.

21. Tissue- group of similar cells and their products that carry out a specific function Organs- groups of tissues that perform a particular job Organ System- group of organs that perform a specific task (circulatory system)