Topic 1.2 – Ultrastructure of Cells PART 1 Comparing microscopes Prokaryote structure and ultrastructure

NOS- Invention of Electron Microscope Most progress in biology is due to the invention and improvements to microscopes Compound Light Scopes: Second half of 19th century Larger (> .2 µm) cell structures were now clear and visible Chromosomes (mitosis, meiosis) Mitochondria, chloroplasts Electron Microscopes: Developed in 1930’s, regular use by 40’s and 50’s Clear images produced for objects as small as .001µm Dark green areas of chloroplasts were found to be small stacks of membranes (grana) Mitochondria has intricate membrane structure These structures are called “ultrastructures” because they are so small Other things discovered- Ribosomes, lysosomes, and ER

Picture of Electron Scope http://www.youtube.com/watch?v=8-oCZ_JEgbM Video of crazy images http://www.jeolusa.com/PRODUCTS/TransmissionElectronMicroscopes(TEM)/200kV/JEM-2100F/tabid/208/Default.aspx

NOS- Your turn Discuss how developments in scientific research follow improvements in an apparatus:

Comparing resolutions of Light vs Electron scopes https://www.youtube.com/watch?v=znSQ9A7OPVc Define Resolution: Making the separate parts of and object distinguishable by the eye Light Electron Visible light has a longer wavelength Maximum res is .2µm (200 nm) Limited by wavelength of light which is 400-700nm Making stronger lenses doesn’t help because we cant’ change the wavelength Electron beams have a shorter wavelength Maximum res is .001µm (1 nm) Why do electron microscopes have a stronger resolution at higher magnifications? ans. Electron beams have a shorter wavelength allowing for higher resolution

Prokaryotic Cell Structure http://www.flickr.com/photos/niaid/7316101966 http://salmonellafordummies.weebly.com/ Prokaryotic Cell Structure

What are the characteristics of a PROKARYOTIC cell? No nucleus- DNA is “free floating” in a nucleoid Found everywhere on Earth Cell Membrane Cell wall made of peptiodoglycan Cytoplasm fills entire cell interior NO compartments (compartmentalization) Ribosomes are the only ultrastructure 70S (Svedburg units), smaller than those found in a eukaryote

http://www.wiley.com/legacy/college/boyer/0470003790/animations/cell_structure/cell_structure.swf

70S

70S

70S

http://www.youtube.com/watch?v=gEwzDydciWc

Topic 1.2- Ultrastructure of Cells Part 2: Eukaryotic Cells https://www.youtube.com/watch?v=gFuEo2ccTPA

Label the animal cell below

Eukaryotic cells are complex What does it mean for a cell to be compartmentalized: The cell is divided up into partitions composed of single or double membranes. Organelles are located in these compartments Most important compartment is the nucleus Compartments are known as organelles What are the advantages of compartmentalization? Enzymes and substrates are less spread out making reactions more efficient Damaging substances can be kept within a certain area so they won’t harm the cell Optimum pH for certain processes can be maintained in a specific location Organelles can be moved around within the cell

How did eukaryotic cells evolve?

Note how it ACTUALLY LOOKS in the micrograph

Using your text p21-23 Label and bullet the job and description of the following structures in the diagram: Nucleus- Rough ER-

ER and ribosomes

Organelles con’t…… vesicle Golgi Apparatus- Lysosome- Golgi Lysosome

Organelles con’t…… Mitochondrion- Free ribosomes-

Organelles con’t…… Chloroplast Vacuoles-

Organelles con’t…… Microtubules- Centrioles-

Organelles con’t…. Cilia- Flagella-

Skills: Identifying ultrastructures in a micrograph; Drawing the ultrastructures based on a micrograph Directions: Using the handout provided, you will develop skills identifying and drawing eukaryotic cell ultrastructures

Exocrine Gland of Pancreas Exocrine glands secrete digestive enzymes into small intestine Enzymes are proteins, so which structures would we expect to see a lot of in these cells?

Exocrine gland cell of pancreas - Label the cell

Palisade mesophyll Cell -Label the visible structures

Comparing Eukaryotes and Prokaryotes: http://www.mwit.ac.th/~ooy/e-cell/activity/cell.swf

Label the parts of the plant cell