Eukaryotes, Prokaryotes, and Virus

1. Eukaryotes, Prokaryotes, and Virus Section 7.1 Pg. 176-180 Section 18.1 pg. 489-492

2. The Cell Theory • Robert Hooke an English scientist is the one who came up with the cell theory. • Cell theory (3 parts) • All organisms are composed of one or more cells • The cell is the basic unit of organization or organisms • All cells come from preexisting cells

3. Two Basic Cell Types • Prokaryotes: unicellular organisms, such as bacteria, composed of prokayotic cells. Prokaryotic cells lack internal membrane-bound structures

4. Two Basic Cell Types • Eukaryotes: unicellular or multi-cellular organisms, such as yeast, plants, and animals, composed of eukaryotic cells, which contain a true nucleus and membrane-bound organelles.

5. Two Basic Cell Types • Eurkaryotic cells contain membrane- bound structures called organelles. • Each organelle has a specific function for cell survival. • Example: Nucleus, mitochondria, and Golgi apparatus

6. Viruses • Definition:disease-causing, nonliving particles composed of an inner core or nucleic acids surrounded by a capsid. • Examples • HIV • Influenza • Common Cold • Polioviruses • Rabies viruses

7. Viruses • Not considered living • Don’t carry out respiration • Don’t grow • Don’t develop • Can replicate (copy themselves) by using a host cell. • Host cell is any cell which viruses can replicate

8. Viral Structure • Contain • Inner core of nucleic acid, either RNA or DNA • Outer coat of protein called capsid. • The DNA and RNA contains instructions for making copies of the virus. • The protein arrangement in the capsid determines the virus’s shape, which determines how the virus infects the cell.