Chapter 2: The Structure of Viruses and Cells

VIRUSES Virus- piece of hereditary material covered by protein that infects & reproduces ONLY inside a living cell – The living cell is called a host cell

VACCINES Vaccine- made from damaged virus particles that can’t cause disease anymore Edward Jenner (1796) - Developed the first vaccine for smallpox

Latent vs. Active Viruses Latent- appear to “hide” inside host cell for a certain period of time, until there is a stimulus – Herpes, mononucleosis, HIV, invading flu, cancer Active- exhibiting symptoms for the disease – AIDS, flu with symptoms

Viral Diseases DiseaseAffected Body PartVaccine AIDSImmune systemno Chicken PoxSkinyes Common ColdRespiratory Systemno Influenza (flu)Respiratory Systemyes HPVCervix (female)yes HerpesSkinno PneumoniaRespiratory Systemyes SmallpoxSkinyes

HIV/AIDS HIV = human immunodeficiency virus AIDS = acquired immune deficiency syndrome HIV is the virus that causes the disease AIDS. HIV is spread through: sexual contact, sharing needles with an infected person, blood & body fluids, infected mother to unborn child

How does temperature affect viruses? Graphing Activity page 37 X axis = Temperature (celsius) Y axis = Viruses (millions)

Things to put in your line graph 1.Title: The Impact of Temperature on the Number of Viruses 2.Label the x and y axis (x is temperature (C); y is number of viruses (millions) ). 3.Intervals for y, each line is 0.05, but just label 0.1, 0.2, etc. (skip two boxes, one line break) 4.Break on x axis 5.Use whole numbers on x axis, start at 36 and skip 5 boxes b/w each number. 6.Put your name in upper right hand corner, include t- chart, degrees C on points (dots), questions answered on back.

Answer the following questions on the back of your graph. 1.What happens to the number of viruses as the temperature increases? 2.Why do we get a fever when a virus is attacking our body? 3.What would happen if one had a virus in his/her body, but his/her immune system did not respond?

Cells Cell: The smallest unit of life. The smallest unit of an organism that can perform all life functions. (grow, reproduce, attain energy and get rid of waste, adaptation)

Cell Theory 1.All organisms are made up of one or more cells. 2.Cells are the basic units of structure and function in all organisms. 3.All cells come from cells that already exist.

Discovering Cells Robert Hooke first observed cells. (1665) He viewed a piece of cork under a microscope and saw small boxes that looked like cells in a monastery. You see this He drew this

Microscopes Simple (1 lens) – Anton van Leeuwenhoek Complex (2 lenses) – Zacharias Janssen Compound Light Microscope