Wajaisha Lab Report
The results above show group wajaisha from class 1a obtained different results compared to my group. Wajaisha’s group used pH 4 and my group also used pH 4. The results that we obtained were after five days we had 35 cells present however wajaisha’s group obtained 42 cells after five days. My group obtained a value of 28000000 per litre and wajaisha’s group obtained 33600000 per litre. Our results may have been slightly different due to us not being able to record the number of cells present on the petri dish clearly. This may have been due to the microscope not having a higher resolution thus affecting the accuracy of the results being obtained. Furthermore, the group MRSA also did the same practical but they used pH 2. The results that they obtained were that there were 45 cells present on the petri dish after five days. MRSA also obtained a value of 36000000 per litre.
Bacteria grow by binary fission and yeast grows by budding but the patterns of growth for a population are the same. There are many phases of microbial growth. These are lag phase which is when the microbe starts …show more content…
getting used to the environment it is in, the exponential phase which is when the cells is in its optimum state of growth and starts to divide via binary fission or budding yeast at its maximum rate, the stationary phase which is where the waste products start to build up and thus hinder growth and the final stage which is the death phase.
Optical techniques can be used to determine the number of cells much accurately by measuring the turbidity.
The amount of light that is scattered is equal to the number of cells. A colorimeter may also be used to determine the absorbance much easily and accurately. This would be at around 400nm – 600nm. A haemocytometer can also be used to count the number of microorganisms present in a culture. This is not the best method to use because it counts all the cells present however some of these cells may be dead thus providing inaccurate results. Viable counts can also be used to determine the amount of living cells in a culture. This method involves the spreading of a culture onto an agar plate. Once the bacterium sits on the nutrient medium it will divide by binary fission to leave 2, 4 and 8 etc until a colony of bacteria is observed. Each of these colonies will represent one
bacterium.
As the temperature increases, the growth of the cells also increases and the chemical reactions start speeding up. However, if the temperature reaches a certain level, the proteins and nucleic acid start to become denatured and thus loose metabolism. Obligate aerobes only grow when there is oxygen present. If there is no oxygen present, then these will not grow. Facultative anaerobes can grow even if there is no oxygen present. However, if oxygen is present then they can respire better and thus grow better.
Bacteria grow by binary fission and yeast grows by budding but the patterns of growth for a population are the same. There are many phases of microbial growth. These are lag phase which is when the microbe starts …show more content…
getting used to the environment it is in, the exponential phase which is when the cells is in its optimum state of growth and starts to divide via binary fission or budding yeast at its maximum rate, the stationary phase which is where the waste products start to build up and thus hinder growth and the final stage which is the death phase.
Optical techniques can be used to determine the number of cells much accurately by measuring the turbidity.
The amount of light that is scattered is equal to the number of cells. A colorimeter may also be used to determine the absorbance much easily and accurately. This would be at around 400nm – 600nm. A haemocytometer can also be used to count the number of microorganisms present in a culture. This is not the best method to use because it counts all the cells present however some of these cells may be dead thus providing inaccurate results. Viable counts can also be used to determine the amount of living cells in a culture. This method involves the spreading of a culture onto an agar plate. Once the bacterium sits on the nutrient medium it will divide by binary fission to leave 2, 4 and 8 etc until a colony of bacteria is observed. Each of these colonies will represent one
bacterium.
As the temperature increases, the growth of the cells also increases and the chemical reactions start speeding up. However, if the temperature reaches a certain level, the proteins and nucleic acid start to become denatured and thus loose metabolism. Obligate aerobes only grow when there is oxygen present. If there is no oxygen present, then these will not grow. Facultative anaerobes can grow even if there is no oxygen present. However, if oxygen is present then they can respire better and thus grow better.