CELLS AND CELL PROCESSES SOME RANDOM CELL FACTS

CELLS AND CELL PROCESSES

SOME RANDOM CELL FACTS • The average human being is composed of around 100 Trillion individual cells!!! • It would take as many as 50 cells to cover the area of a dot on the letter “i” WOW!!!

CELL THEORY 1. All organisms are made up of one or more cells. An organism can be one cell or many cells like most plants and animals. 2. The cell is the basic unit of organization in organisms. Even in complex organisms, the cell is the basic unit of structure and function. 3. All cells come from existing cells.

BACKGROUND • In the 17 th century, scientists used a new invention, the microscope, to explore the newly discovered microscopic world. • 1665: Robert Hooke cut a thin slice of cork and looked at it under his microscope. To Hooke, the cork seemed to be made of empty little boxes that he called cells. Robert Hooke Matthias Schleiden • 1830 s: Matthias Schleiden used the microscope to view plants. He determined that all plants are made of cells. – Theodore Schwann used the microscope to view animal cells. He determined that all animals are made of cells. Theodore Schwann

BACKGROUND • 1830 s: Rudolf Virchow observed that cells divide to form new cells. He proposed that every cell came from a cell that already existed. ALL LIVING THINGS ARE MADE OF CELLS. Rudolf Virchow

MODERN CELL THEORY Modern Cell Theory contains 4 statements, in addition to the original Cell Theory: • The cell contains hereditary information (DNA) which is passed on from cell to cell during cell division. • All cells are basically the same in chemical composition and metabolic activities. • All basic chemical & physiological functions are carried out inside the cells. (movement, digestion, etc. ) • Cell activity depends on the activities of subcellular structures within the cell (organelles, nucleus, plasma membrane)

HOW HAS THE CELL THEORY BEEN USED? • The basic discovered truths about cells, listed in the Cell Theory, are the basis for things such as: – Disease/Health/Medical Research and Cures(AIDS, Cancer, Vaccines, Cloning, Stem Cell Research, etc. )

VIRUSES • A virus is a strand of hereditary material surrounded by a protein coating. • Viruses do not have a cell membrane, a nucleus or other organelles. • Viruses cannot copy themselves without a host cell. Methods of Attack 1. ) Active 2. ) Latent (inactive)

VIRUSES • A virus cannot move by itself. – Viruses can land on a plant surface by wind or inhaled by an animal. Fighting Viruses • Vaccines: Made from weakened virus particles that cannot cause disease anymore. • Interferons: proteins that are produced rapidly by virus-infected cells and move to noninfected cells in the host. They cause noninfected cells to produce protective substances.

VIRUSES