Cell Parts and Functions

1590- invention of the microscope made it possible to look at very small objects (Janssen) Robert Hooke observed cells in a piece of cork Leeuwenhoek viewed single celled organisms from a pond and observed the first bacteria.

1838 Schleiden, a German scientist, concluded that all plants are made from cells 1839 Schwann, a German scientist concluded that all animals are made from cells 1855 Virchow proposed that all new cells come from cells that already exist.

Cell Theory All living things are composed of cells. Cells are the basic unit of structure and function in living things. All cells are produced from other cells.

Structure Structure- what it is made of and how it is put together. –Cells, tissues, organs, organ systems –Brain cell, brain tissue, brain, nervous system –Different organs work together to form an organ system (brain, spinal cord, nerves, glands, muscles)

Function Function- are processes that allow an organism to stay alive and reproduce. –Obtaining oxygen, getting rid of waste, obtaining food, growth –Organs and organ systems work together to accomplish different functions. –Your respiratory system works to bring in oxygen while it is the circulatory system that distributes the oxygen to all the cells in the body.

How Big are Cells? One square centimeter of your skin contains more than 100,000 cells. Are all cells the same size? cells/scale/ cells/scale/ Are all cells the same size?

Cell Membrane “Gatekeeper” of cell Has pores in it Controls the movement of material 3 layers – fat layer between two proteins Cell membrane is like a guard.

Cytoplasm Most of the cell Where cell materials are produced Made of a jellylike substance Cytoplasm is like the factory building

Nucleus Controls cell activity The “Brains” of the cell The Nucleus is like the Boss’ office

Nuclear Membrane Same make up as the cell membrane Controls movement of materials into the nucleus The Nuclear Membrane is like the boss’ secretary

Nucleolus Where the genetic material (DNA) is housed The Nucleolus is like the boss

Mitochondrion The “Powerhouse of the cell Involved in changes that release energy for the cell Mitochondria are like the power plants of the cell.

Ribosomes Proteins are made there Ribosomes are like the stations on an assembly line.

Endoplasmic Reticulum Network of tubes that connect the cell and nuclear membrane. Moves materials through the cell. Endoplasmic Reticulum is like an assembly line.

Vacuole Holds water and dissolved materials A vacuole is like the warehouse

Golgi body Where the proteins are packaged The Golgi body is like the final inspection station/wrapping department

Lysosomes The “Garbagemen” of the cell Digests harmful substance and cleans the cell The lysosomes are like the custodians

Cell wall Nonliving layer surrounding the cell membrane Provides shape and support Found only in plants The cell wall is like the outer fence.

Chloroplasts Contains chlorophyll Found mostly in leaves Used by the plant to make food The chloroplasts are like the cafeteria.

The End