1. Unit 2: Cells & Viruses

2.  SB1a. Explain the role of cell organelles for both prokaryotic and eukaryotic cells, including the cell membrane, in maintaining homeostasis and cell reproduction.  SB1d. Explain the impact of water on life processes (i.e., osmosis, diffusion).  SB3d. Compare and contrast viruses with living organisms. Vocabulary & Contents:  Pg 11 Prokaryote / Eukaryote  12nucleus / ribosome  13endoplasmic reticulum / golgi apparatus  14vacuole / lysosome  15mitochondrion / chloroplast  16cell wall / cell membrane  17Venn Diagram: Plant & Animal Cells 10

3. Vocabulary & Contents (continued):  Pg 18 diffusion / osmosis  19facilitated diffusion / isotonic  20hypertonic / hypotonic  21active transport / homeostasis  22Passive Transport Diagram  23virus / capsid  24Venn Diagram: Viruses & Living Organisms

4. The origins of cell study  Individual cells are so small, they are seen in detail only with a :  microscope.

5. The first microscope  Was designed by Anton van Leeuwenhoek in the 1600s.  Really, it was a piece of glass.  In 1665, Robert Hooke used a compound microscope to see cork “cells”.

6. Current Study of Cells: Microscope Technology  Three Types:  Light Microscope (LM)  Transmission Electron Microscope (TEM)  Scanning Electron Microscope (SEM)

7. Current Study of Cells: Microscope Technology  Light Microscope (LM)

8. Current Study of Cells: Microscope Technology  Transmission Electron Microscope (TEM)

9. Current Study of Cells: Microscope Technology  Scanning Electron Microscope (SEM)  insect wing

10. Development of the Cell Theory  Robert Hooke was the first to see and name “cells.”  Two other scientists, Shleiden (studied plants) and Schwann (studied animals), were the first to write that living things are composed of cells.  Their conclusions contributed to what is now called the Cell Theory.

11. Development of the Cell Theory The Cell Theory says:  All living things are made of one or more cells.  The cell is the basic unit of an organism.  All cells come from other living cells.

12. Characteristics of Cells  Two main types: prokaryotes and eukaryotes.  Prokaryotes do NOT have a true nucleus.  Eukaryotes have a true nucleus.  There are other differences as well…

13. Prokaryotic Cell Cell membrane Cytoplasm Nucleus Organelles Eukaryotic Cell Section 7-1 Prokaryotic and Eukaryotic Cells Go to Section:

14. Eukaryotic Cells  Eukaryotic cells have internal membrane- bound structures called organelles.  Organisms that are eukaryotic can be uni- or multi- cellular.  Unicellular organisms are able to carry out all of life’s functions.  Multicellular organisms can have specialization of cell groups (tissues).  Examples: include fungi, amoeba, plants, and animals.

15. Prokaryotic Cells  Prokaryotic cells lack membrane-bound organelles.  They still have DNA, but no nucleus to enclose it.  Examples include: all bacteria.

16. Plant Cell Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Mitochondrion Cell wall Cell Membrane Chloroplast Vacuole Section 7-2 Figure 7-5 Plant and Animal Cells Go to Section: Vacuole Chloroplast Cell Membrane Cell wall Golgi apparatus Mitochondrion Smooth endoplasmic reticulum Ribosome (free) Ribosome (attached) Nuclear envelope Nucleolus Nucleus Rough endoplasmic reticulum

17. Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion Section 7-2 Go to Section: Microtubule Microfilament

18. Animal Cell Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrion Cell Membrane Ribosome (free) Ribosome (attached) Section 7-2 Figure 7-5 Plant and Animal Cells Go to Section: Rough endoplasmic reticulum Cell Membrane Nucleus Nuclear envelope Nucleolus Smooth endoplasmic reticulum Golgi apparatus Mitochondrion Ribosome (attached) Ribosome (free) Centrioles

19. Prokaryotes Eukaryotes Cell membrane Ribosomes Cytoplasm Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Animal Cells Plant Cells Lysosomes Centrioles Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Venn Diagrams Go to Section:

20. Viruses  Non-living strand of genetic material with a protein coat  No organelles  Do not move  Cannot replicate on their own  Size: 5 – 300 nm (nanometers – about 1 billionth of a meter)

21. HIV virus bursting out of white a blood cell

22. Viral Diseases  AIDS (caused by HIV)  Herpes  Measles  Mumps  Chicken Pox, Shingles  Cold  Influenza “the flu”  “Swine Flu”  Warts  Gastroenteritis  Polio  viral meningitis  rabies  Small Pox**  Hepatitis

23. More images of viruses H1N1 virus “Swine flu”

24. More images of viruses Herpes virus Tobacco mosaic virus

25. All about viruses Where did viruses come from?  Possibly parts of cells –Genetic material of viruses is similar to that of cells Viral Structure  Covered by an outer layer of proteins called a capsid  Inside the capsid – genetic material – could be DNA or RNA

26. Viral Infections  Viruses do not have ribosomes or mechanism for making proteins  They cannot function or reproduce on their own  To replicate, viruses must infect host cells –Two types of viral reproduction  Lysogenic  Lytic

27. Lytic Cycle  Host cell makes copies of its own DNA as well as viral DNA or RNA  Invading genetic material instructs the host cell to make more viral protein capsids & enzymes needed for viral replication  With those copies of DNA and protein, new viruses start to form  Host cell lyses or “explodes” and releases thousands of new viruses

28. Lysogenic Cycle  Lysogenic = literally “can initiate a lysis of the cell” but it doesn’t do it right away  Viral DNA inserts into DNA of host cell  DNA stays dormant (it hides/rests) for a length of time  Under the right conditions, the viral DNA is activated and the Lytic Cycle begins  Examples—chicken pox-> shingles, HIV

29. http://www.geocities.com/madokagm/BIOL1551/lecture_notes_Nov_22_files/image002.jpg

30. Fighting Viral Disease  Antibiotics are ineffective against viral infections  The only way to fight a virus is with the immune system by: –Fighting an existing new viral infection –Preventing the severity of viral disease by vaccination: A vaccine is a killed or weakened virus that is injected into a person so their immune system (1) gets a preview of what the virus looks like (2) Can respond quickly so that the virus will not totally infect the person and make them ill

31. Virus Variations & more  Retrovirus –Has RNA instead of DNA –Ex. HIV Virus that causes AIDS  Prions –Proteins that can cause infectious diseases For example: –Mad Cow Disease, Creutzfeldt-Jakob Disease

32. How much do you know?  What is the difference between a virus and a retrovirus?  What type of virus is HIV?  Do prions have genetic material?  Are viruses living? Give one reason why or why not?  Are viruses bigger or smaller than normal cells?  Do antibiotics work against viruses?