RESPOND THOUGHTFULLY TO THIS DISCUSSION POST The Question: How would the use of bacteriocidal, bacteriostatic or bacteriolytic antimicrobial agents differ in their resulting cell counts (total and viable). How would the effects differ regarding the growth curve of the cells? Use examples to support your answer.

The Person's There are 3 different ways antimicrobial agents can affect microorganisms. One way is bactericidal, where the antibiotic can kill all the cells, but the total cell count is still present since the dead cells were not destroyed. That means we can still count the cells on a Petri dish, but the cells are no longer living. The viable cell count goes down, but the total number stays the same after the antimicrobial agent is added. An example of such an agent is penicillin since it binds to biosynthetic proteins involved in peptidoglycan synthesis and thus prevents cell wall formation.
Another way is bacteriostatic when the antibiotic stops bacterial growth. However, if the bacteria aren't all dead before the agent was removed, the bacteria can continue growing as they did previously. That means the cell count and viable cell count are the same. Both lines will follow the same pattern. An example in the text was Triclosan. At high concentrations, it is bactericidal, but at low concentrations, it only inhibits the fatty acid synthesis and thus only bacteriostatic. This doesn't necessarily kill the bacteria; it just inhibits it from growing temporarily until it is removed.
Lastly, there's bacteriolytic, which kills the cell as well as lowers the total cell count. This means the viable and total count both go down when the agent is added. Cell lysis decreases viable and total cell count. Since some bactericidal agents can also be bacteriolytic, penicillin can be used again as an example since it ruptures the cytoplasmic membrane.

Environmental science studies the interactions between the physical, chemical, and biological components of the environment, including their effects on all types of organisms. earth science (also known as geoscience), is an inclusive term for all sciences related to earth (geology, meteorology, oceanogr maphy, etc).  although environmental and earth science cover essentially the same material, environmental science places greater emphasis on the biological realm, while earth science places greater emphasis on the physical realm.    environmental and earth science study the interactions of four major systems or “spheres” (figure 8.6).  the  geosphere  consists of the core, mantle and crust of the earth.the  atmosphere  contains all of the earth’s air and is divided into troposphere, stratosphere, mesosphere, thermosphere and ionosphere.the  hydrosphere  contains all of the solid, liquid and gaseous water on earth, extending from the depths of the sea to the upper reaches of the troposphere where water is found.  ninety-seven percent of the hydrosphere is found in salty oceans, and the remainder is found as vapor or droplets in the atmosphere and as liquid in ground water, lakes, rivers, glaciers and snowfields.  the  biosphere  is the collection of all earth’s life forms, distributed in major life zones known as biomes:   tundra, boreal forest, temperate deciduous forest, temperate grassland, desert, savannah, tropical rainforest, chaparral, freshwater, and marine.although the four systems have their unique identities, there is substantial interaction between them.  environmental scientists study the effects of events in one sphere on the other spheres. for example, a volcanic eruption in the geosphere may cause profound direct and indirect effects on the hydrosphere, atmosphere and biosphere as follows: example 1 (volcano)    on may 18, 1980, mount saint helens, in the state of washington, erupted.  this event altered the surrounding environment, and provided scientists with an opportunity to study the effects of volcanic eruptions on the geosphere, hydrosphere, atmosphere and biosphere.  such studies are vital because volcanic eruptions will continue to occur, and will have increasing impact on humans as people continue to settle lands closer to dormant volcanoes. the following are but a few of the myriad of interactions resulting from a volcanic 

Telophase colchicine is a chemical obtained from plants that prevents the assembly of spindle fibers