Cytology Chapter 6

Cell Theory Why is this considered a “theory”? Light Microscopes Anton Von Leeuwenhoek - Early 1600’s Robert Hooke – 1665 – named “cell” What was he viewing? Three parts of cell theory All living things made of cells Cells basic unit of structure and function All cells come from preexisting cells

Microscopes Video- United Streaming Compound light Limitation is resolution Transmission electron (TEM) – mid 1940’s Scanning electron (SEM) – late 1950’s Discuss similarities and differences Discuss advantages and disadvantages

Cells - An overview Organelles Plasma membrane Nucleus Cytoplasm Compartmentalization of cell functions Plasma membrane Nucleus Cytoplasm Cell wall Eukaryotic vs. prokaryotic

Which cell is which? Let’s draw a Venn diagram

6.2 Membranes What surrounds the cell and its organelles? What are the similarities and differences between the plasma membrane and our classroom walls? What about the cell wall?

Membranes - Structure What type of biomolecules makes up the plasma membrane? Why does this fit structure and function theme?

Phospholipid Bilayer

Membrane Proteins What are some membrane protein functions? (plasma membrane and other membranes) Online Activity 6.3 Construct a Cell Membrane

Membrane Traffic Regulation 6.3 Materials such as water, nutrients, dissolved gases, ions, and wastes must constantly move in two-way traffic across a cell’s membranes. Membrane designed to regulate and control what moves and when it moves!

Diffusion What’s that smell? Define concentration Concentration gradient Equilibrium Can occur across membrane – such as window screen. What does permeable mean? What does selectively permeable mean?

Passive Transport No energy needed – chemicals move down concentration gradient Diffusion – Gases – oxygen and carbon dioxide- through phospholipid bilayer Water can’t move through PL-bilayer – Why?? Facilitated diffusion Help received from proteins Water, some sugars

Contrast diffusion and facilitated diffusion

Osmosis Egg demo Passive transport of WATER Key Terms: “Rules”: Hypertonic Hypotonic Isotonic “Rules”: -tonic refers solute Water flows from hypotonic to hypertonic (from lower solute concentration to higher solute concentration) Link for review of osmosis – hypertonic and hypertonic Link to review semipermeable membrane and osmosis

Review of Cell Transport Interactive Website

Osmosis in Animal and Plant Cells Plasmolysis Turgor pressure

Active Transport ATP required! Nerve cells (Na+/K+ pumps)

Transport of Large Molecules Cells “packages “ invesicles Exocytosis Endocytosis

Introduction: What proportion of a cell is composed of water? What’s the rest made up of?

How is a cell like our school? What types of different things go on in a school? What types of different things go on in a cell? How are they separated?

6.4 The cell builds a diversity of products Nucleus- which room of EHS would the nucleus be? If the cell were as big as our classroom, how big would the nucleus be? http://www.cdli.ca/~dpower/cell/nucleus.jpg

Ribosome and Endoplasmic Reticulum What do ribosomes do? What happens in the Endoplasmic Reticulum (ER)? Rough ER Smooth ER http://micro.magnet.fsu.edu/cells/endoplasmicreticulum/images/endoplasmicreticulumfigure1.jpg

Golgi Apparatus Where in EHS would you find the Golgi Apparatus? How big would it be if the cell were the size of our classroom? What is the function of the Golgi apparatus? http://ghs.gresham.k12.or.us/science/ps/sci/soph/cells/pics/er-golgi1.jpg

Vacuoles, Lysosomes, and other Vesicles Vacuoles usually store undigested nutrients Vacuoles in plants – provide turgidity Some contain colored pigments (not chlorophyll) Lysosomes digest and recycle. Involved in “digesting” phagocytized microbes In some cases commit “suicide” Vesicles are constantly budding from one organelle and fusing with others. Online Activity 6.4

6.5 Chloroplasts and Mitochondria Online Activity 6.5 What is the function of chloroplasts? What is the function of a mitochondrion (pl. mitochondria)? What are the products of each??

6.6 Internal skeleton of cells Cytoskeleton (cyto means “cell”) What are the functions of microtubules and microfilaments? Flagella and Cilia Where do you find each? How do they move the cell? Online Activity 6.6 Cell is a Coordinated Unit!