Exploring Bacteria, Viruses, and Cells

1. Bacteria, Viruses, and Cells

2. Bacteria, Viruses, and Cells We are going to discuss the similarities and differences in Bacteria, Viruses, and Cells By the end of the lesson you should be able to explain: • Whether or not they are alive and how we can tell • How they Reproduce • What type of genetic material they contain • And give some examples of each

3. Eukaryotic Cells Bacteria Viruses

4. Prokaryotes Can be beneficial or harmful No internal compartments or membrane systems They are single celled Three basic shapes Bacillus –rod Coccus – round Spirillum – spiral Antibiotics do kill them Segments of Nucleic Acids contained in a protein coat (capsid) Some have an envelope around the capsid Not prokaryote or eukaryote Much Smaller than Bacteria and Cells Variety of shapes Antibiotics do not kill them Only harmful Basics Eukaryotic Cells Bacteria Viruses • Eukaryotes • Have organelles • Many different types and they can be specialized

5. Bacteria Are ALIVE They can metabolize food They do contain Ribsomes to make proteins They can reproduce without a host cell Viruses are NOT ALIVE They cannot metabolize food They have no structures to make proteins (ribosomes) They cannot reproduce without a host cell Are they alive and How do we know? Eukaryotic Cells Bacteria Viruses • Cells are ALIVE • They can metabolize food • They do contain ribosomes to make proteins • They can reproduce without a host cell • Interact with their surroundings

6. Bacteria reproduce by a process called Binary Fission Viruses have 2 possible ways of reproducing Lytic Cycle Lysogenic Cycle How do they Reproduce? Eukaryotic Cells Bacteria Viruses • Cells reproduce • Mitosis – for most cells • Meiosis - for gamete cells

7. DNA and RNA DNA is found in the cytoplasm because Bacteria have no nucleus Round DNA DNA OR RNA, but not both What Type of Genetic Material Do They Have? Eukaryotic Cells Bacteria Viruses • DNA and RNA • DNA Found in the nucleus • Linear DNA

8. Bacteria and viruses are transmitted in much the same way Inhalation Direct Contact Contact with Body Fluids (Blood, Saliva, semen) Contaminated food or water Bite of an infected animal or insect How are they transmitted? Bacteria Viruses

9. Cholera Dental Cavities Strep Throat Tetanus Used in making food and beverages Mycorrhizae AIDS Common Cold Flu Rabies Hepatitis Smallpox Examples Bacteria Cells Viruses • Muscle cells • Nerve Cells • Guard Cells

10. TAKS Question Which of the following is found in both cells and viruses? • A Silica • B Genetic material • C Digestive cavity • D Flagella

11. TAKS Question Viruses differ from bacteria in that all viruses — • F cause insect-borne diseases • G can be destroyed by antibiotics • H have rigid cell walls • J must be reproduced in living cells

12. TAKS Question What process is shown to the left? • A Cellular ingestion • B Pseudopod formation • C Cell wall digestion • D Binary fission

13. TAKS Question Which of the following cannot metabolize nutrients?

14. TAKS Question What is the most common threat to a host organism posed by an invading virus? • A Production of viral fluids in the bloodstream • B Fermentation of acids in the digestive system • C Destruction of cells by viral reproduction • D Stimulation of muscle tone in the heart

15. TAKS Question Which of these does a virus need in order to multiply? • A Chloroplasts from a host cell • B A host cell to provide oxygen for the virus • C New ADP from a host cell • D A host cell to replicate the virus’s DNA