While different types of bacterium have varying diets, they all require nutrients to provide energy. Energy is necessary to fuel work inside the cell. Many bacteria use the carbon, nitrogen, phosphorus or sulfur from their nutrient source to produce energy.
These elements are broken down during cellular respiration to make a coenzyme called adenosine triphosphate, which transports that chemical energy to places within the cell that are consuming energy.
Some bacteria get their energy from sunlight using unique metabolic methods. Scientists who grow bacteria in a laboratory use concentrated growth media containing readily available carbon, nitrogen, sulfur and phosphorus along with many vitamins and minerals. They choose different media depending on the preference of the bacterium they wish to grow.
Approximately 70 percent of a bacterial cell is composed of water. Complex multi-cellular organisms, such as humans, can ingest their own water. Single-celled bacteria lack that ability, so they must rely on finding enough available water in their environment to through their cell membranes.
Many bacteria can survive for extended periods without moisture, but without it they can't grow and reproduce. Outside of nutrients and water, each species of bacteria has a specific environmental preference.
Bacteria can live in hotter and colder temperatures than humans, but they do best in a warm, moist, protein-rich environment that is pH neutral or slightly acidic. There are exceptions, however. Some bacteria thrive in extreme heat or cold, while others can survive under highly acidic or extremely salty conditions. The state of Florida neither endorses links nor approves of links to external sources. External links are made available for the convenience of the internet user.
The state of Florida takes no responsibility for a link's operation or content. M endel's M other shows you -- how bacteria grow. The results of each of your investigations should be recorded as a table a Table of Results. In these tables you should indicate the name of the microbe being studied, the temperature growth, and make an accurate record of either the growth data growth curve , or the value of the generation time generations per minute , as required. The logatithmic value of the generations per hour should also be recorded on your table of results.
The results of each investigation should then be presented as a graph. The horizontal axis of the graph should be the intervals of the different temperatures at which the microbes were grown. The vertical axis should represent the logarithmic value of the generations per hour determined for that sample. This is called a Arrhenius plot. The shape of these graphs or plots is characteristic for each species of microbe, but each organism will show an optimum temperature where growth proceeds most rapidly, and as the temperatures either exceed, or fall below that optimum, growth slows down.
Above or below the maximum and minimum permissive temperatures, all growth stops. Each investigation is carried out under a specific set of growth conditions. A species of microbe is chosen first. It is then necessary to chose a temperature. Use the thermometer sliding scale to set the chosen temperature. The value chosen will appear in the box. In some investigations you will need to record the entire growth curve data on extreme right , but for most investigations you only need to record the "generations per minute" and "log.
Record all the temperatures and all the values where you see that the microbial species could grow at all. It is not necessary to record those values that occur when there is not microbial growth.
0コメント