CHAPTER 4 CELLS

4.1 History of Cell Biology OBJECTIVES: Name scientists who first observed living and non living cells. Summarize research that led to cell theory. State 3 principles of Cell Theory Explain why cells are basic units of life

Discovery of Cells Hooke Leeuwenhook Discovered cells in cork 1st to observe dead cells Leeuwenhook First to observe living cells Described first cells as animulcules

Cell Theory Cell Theory has 3 parts All living organisms are composed of one or more cells. Cells are the basic units of structure. Cells come only from the reproduction of existing cells.

Cellular Basis of Life All living things Have cells Obtain energy Perform chemical reactions Change with time Respond to the environment reproduce

4.2: Introduction to cells Objectives: Describe 3 basic parts Compare prokaryotic and eukaryotic cells Analyze relationship between cells, tissues, organs, organ systems, and organisms

Cell Diversity Cell shape reflects the different functions of the cell. Cells not only differ in the shape but also the size.

Two basic types of cells A. Prokaryotic Cells Do NOT have a nucleus Bacteria B. Eukaryotic Cells Has a nucleus Has organelles

Ribosomes and DNA Has Nucleus No Nuclear Membrane

Cell Organelles Animal Cell Plant Cell

Cell Organelles Plasma Membrane Cytoplasm Nucleus Covers the cell and acts as a barrier between the inside and outside Cytoplasm Fluid inside the cell Nucleus Control center of cell Controls most functions of the cell

Cell Organelles Nucleolus Ribosomes Mitochondria Site of DNA (genetic material) Ribosomes Made of protein Direct construction of protein Mitochondria Powerhouse of the cell Transfers energy

Cell Organelles G. Rough endoplasmic reticulum A. System of flattened sacs B. covered with ribosomes C. produces phospholipids and proteins D. transport system H. Smooth endoplasmic reticulum A. builds lipids (cholestrol) B. Abundant in liver and kidneys C. Detox body

Cell Organelles I. Golgi Apparatus A. Packages materials throughout the cell Lysosomes Contain enzymes Cytoskeleton Microtubules Provide structure Microfilaments Contribute to cell movement

Cell Organelles L. Cilia A. many hairlike structures used for movement Flagella Tail like organelle Assists in movement Tail on human sperm cells Centrioles Organize cytoskeleton for cell division

Cell Organelles Cell Wall Vacuole Chloroplasts Outside plasma membrane Found only in PLANT cells Provides structure Vacuole Storage sac Chloroplasts Used in photosynthesis (green)

Cell WALL

Cell MEMBRANE

Nucleus: control center for the cell

4. Ribosomes: grain like bodies on the ER & in the cytoplasm

5.Endoplasmic Reticulum: (called ER) carry proteins and materials within the cell

6. Golgi Body: receives and packages proteins from ER and distributes around cell and body (mailroom)

7. Cytoplasm: clear gelatinous fluid inside a cell

8. Vacuoles: storage area of the cell Plant has one large vacuole Stores food, waste, & enzymes

9. Mitochondria = powerhouse of the cell; where cell energy comes from.

10. Chloroplasts: ONLY IN PLANTS captures sunlight and produces food for the cell

11. Flagella = used for movement

12. Cilia = used for movement; tiny hair-like structures; found on cells that need to move mucus

COMPARE and CONTRAST Plant and Animal Cells Cell Wall Chloroplasts Large Vacuole Cytoskeleton Nucleus Cell Membrane

Importance of Cell Surface Area What is surface area? The amount of surface for a cell Why is surface area important? When the volume of the cell increases, the surface area increases S.A. limits cell growth because if the cell becomes to large it will not be able to take in enough food and get rid of enough waste