Bacteria, Viruses, and Cells

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

Bacteria Cells Viruses

Basics Bacteria Cells Viruses Eukaryotes or Prokaryotes Have organelles Many different types and they can be specialized 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 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

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

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

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

How are they transmitted? Bacteria Viruses 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

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

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

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

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

TAKS Question Which of the following cannot metabolize nutrients?

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

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