Transcript CELL
THE CELL “The body’s building material” Basic unit of life smallest units that can maintain life and reproduce 1 What do living things have in common? All living things are made of tiny units, called cells. 2 INTRODUCTION • In 1665, Robert Hooke introduced the term “CELL” because the cellulose walls of dead cork cells reminded him of the blocks of cells occupied by monks. • In 1673, Antonie van Leeuwenhoek discovered blood cells, spermatozoa, and a lively world of “animalcules”. • Cell theory was not formulated for nearly 200 years after the introduction of microscopy. 3 •The NUCLEUS was observed by Robert Brown in 1833 as a constant component of plant cells. Next, the nuclei were also observed and recognized as such in some animal cells. •Finally, a living substance called PROTOPLASM was recognized within cells. •After these discoveries, CELLS were considered to contain living material. • In 1839, Thedore Schwann and Matthias Schleiden recognized that some organisms are unicellular and others multicellular. 4 Introduction to Cell Anton van Leeuwenhoek (1670) Robert Hooke (1665) Robert Brown (1831) Matthias Schleiden (1838) Theodor Schwann (1838) Johannes Purkinje (1839) Rudolf Virchow (1858) 1) first to use the term "protoplasm" 2) while studying cork, he was the first to use the term "cell" 3) stated that all new cells come from other living cells 4) studied many microscopic organisms using a strong simple microscope 5) stated that all plants are composed of cells 6) stated that all animals are composed of cells 7) "discovered" the nucleus 5 THE CELL THEORY : 1. all living things are made up of cells & the products of those cells 2. all cells carry out their own life functions 3. new cells come from other living cells 6 Classification of Living Things KINGDOM NAME MONERA PROTISTA FUNGI PLANT ANIMAL KEY CHARACTERISTICS EXAMPLES UNICELLULAR PROKARYOTIC BACTERIA BLUE-GREEN ALGAE MOSTLY UNICELLULAR EUKARYOTIC SOME COLONIAL AMEBA PARAMECIUM EUGLENA ALGAE MOSTLY MULTICELLULAR EUKARYOTIC HETEROTROPHIC SESSILE MUSHROOMS MOLDS & MILDEWS YEAST (unicellular) MULTICELLULAR EUKARYOTIC AUTOTROPHIC SESSILE CELL WALLS made of CELLULOSE MOSS FERNS FLOWERING PLANTS BUSHES TREES MULTICELLULAR EUKARYOTIC HETEROTROPHIC MOTILE SPECIALIZED SENSE ORGANS INSECTS JELLYFISH, HYDRA CRABS FISH BIRDS LIONS,TIGERS,BEARS 7 Biologic Molecules of Cells Carbohydrates Proteins Lipids Nucleic Acids 8 TWO CLASSES OF CELLS EUKARYOTES: Cells with specialized compartments, as stated above. PROKARYOTES: Cells which are simpler and generally smaller than eukaryotic cells. 9 Bacterial Cell 10 Plant Cell Organelles 11 Animal Cell 12 What is an Organelle? Carry out the individuals task of gaining and working with energy, also directing the overall behavior of the cells. 13 Organelle and its description NUCLEUS Main planner of the cell. Contains DNA and RNA & manufactures proteins. MITOCHONDRIA Energy producers of the cell. RIBOSOMES Produce proteins. 14 ENDOPLASMIC transports GOLGI RETICULUM proteins from the nucleus. BODIES produces and packages proteins. 15 What are the important parts of cells? CELL This CELL MEMBRANE surrounds the cell. WALL a stiff wall that surrounds the cell membrane. CYTOPLASM packaging of the cell. 16 AN ILLUSTRATION OF CELL PARTS 17 What are the processes which the cell engages in? DIFFUSION How food, air, and water gets in and out of the cell. PHOTOSYNTHESIS and CELLULAR RESPIRATION How the cell gets energy. 18 LIFE FUNCTIONS ABSORPTION ASSIMILATION CIRCULATION DIFFERENTIATION DIGESTION EGESTION EXCRETION GROWTH INGESTION METABOLISM NUTRITION RESPIRATION REGULATION REPRODUCTION SYNTHESIS 1. OBTAINING & THEN CHANGING MATERIALS INTO FORMS AN ORGANISM CAN USE 2. TAKING IN FOOD FROM THE ENVIRONMENT 3. THE BREAKDOWN OF COMPLEX FOOD MATERIALS INTO FORMS THE ORGANISM CAN USE 4. ELIMINATION OF INDIGESTIBLE MATERIAL 5. PROCESS BY WHICH SUBSTANCES ARE TAKEN INTO THE CELLS OF AN ORGANISM 6. PROCESS BY WHICH MATERIALS ARE DISTRIBUTED (MOVED) THROUGHOUT THE ORGANISM 7. RELEASE OF CHEMICAL ENERGY FROM CERTAIN NUTRIENTS 8. CHEMICAL COMBINATION OF SIMPLE SUBSTANCES TO FORM COMPLEX SUBSTANCES 9. INCORPORATION OF MATERIALS INTO THE BODY OF AN ORGANISM 10. INCREASE IN SIZE 11. PROCESS BY WHICH CELLS BECOME SPECIALIZED FOR SPECIFIC FUNCTIONS 12. REMOVAL OF METABOLIC WASTES 13. PROCESS BY WHICH ORGANISMS MAINTAIN A STABLE INTERNAL ENVIRONMENT 14. PROCESS BY WHICH ORGANISMS PRODUCE NEW ORGANISMS OF THEIR OWN KIND 15. THE SUM TOTAL OF ALL THE CHEMICAL REACTIONS OCCURRING WITHIN THE CELLS OF AN ORGANISM 19 SOME NOTES! •The smallest known cells are a group of tiny bacteria called mycoplasmas. •It would require a sheet of about 10,000 human cells to cover a head of a pin. •Each human being is composed of more than 75,000,000,000,000 cells. 20