Bacteria & Viruses

Learn about bacteria and viruses: their structures, how they work, and how we fight them with medicine.

Structure of Bacteria Label the parts of a typical bacterium. Your choices include: DNA cytoplasm ribosome pili flagellumRemember the program will count off if you misspell or use proper forms of capitalization. Be sure to refer to the choices. flagellum DNA ribosome cytoplasm pili Characteristics of Bacteria Match the characteristic to its description. Pili hairlike structures that help bacteria stick to surfaces Flagellum long whiplike structures that allow bacteria to move Capsule thick covering that protects cells from drying out Bacterial Processes Match the characteristic to its description. Conjugation a way for cells to transfer DNA Fission a way for cells to divide and produce two identical cells Nitrogen Fixation the use of bacteria to convert atmospheric nitrogen into usable compounds Decomposition the use of bacteria to break down dead organisms into useful molecules Bacterial Disease Bacteria can enter your body through a cut, the air you breathe, or the food you eat. Some bacteria make you sick by damaging tissue, while others cause illness by releasing toxins. Antibiotics are medicines that work by preventing bacteria from building cell walls or interrupting the production of proteins. Unfortunately, many types of bacteria are now resistant to antibiotics and are difficult to treat. Bacteria can also be killed by pasteurization, which is a process of heating food to temperatures that kill most harmful bacteria. Viruses A virus is simply a strand of DNA or RNA surrounded by a layer of protein. Viruses do not have all the characteristics to be considered a living organism, and must be inside a cell to replicate. Once viruses enter a cell they can either be active or latent (inactive). Once active, the virus takes control of the host cell and replicates, which ultimately destroys the host cell. Copies of the virus are then released into the host organism, where they can infect other cells. One way to fight a virus is to acquire immunity, which means your body has made special proteins called antibodies that attach to the virus and prevent them from attaching to a host cell, making it useless. Another way to prevent viruses is through the use of vaccines, which trigger the production of antibodies with the use of deactivated pathogens. Bacteria vs. Viruses Sort each description to the column that is the most appropriate. Bacteria prokaryotic living treat with antibiotics mostly beneficial can increase genetic diversity with conjugation Uses the asexual reproduction binary fission to reproduce Viruses non-living can be inactive for years mostly harmful only prevented with immunity (acquired or by vaccine) sometimes treated with anti-viral medications Replicates by the aid of a host