O Bacterial Growth Curve x Hannan - ax E C O https://lindenwood.instructure.com/
ID: 193932 • Letter: O
Question
O Bacterial Growth Curve x Hannan - ax E C O https://lindenwood.instructure.com/courses/30648/assignments/492739&submit; # Apps * Bookmarks D Microsoft Exchange - 0 HP Connected Discussions Grades Stationary People Files Dead Syllabus Quizzes 28 Conferences Collaborations No. of bacterial cells (Log) Log L Proctoru Smarthinking Online Tutoring D Office 365 Purchase Course Materials Lag Time Referencing the figure above, describe the following: 1) what is occurring to the bacterial population during each phase shown in the curve? 2) what is the proportion of living to dead cells during each of these phases, hypothetically speaking? 3) what would be the impact on a subsequent culture if you were to transfer an aliquot of bacteria from each phase to inoculate a sterile broth tube? What would the growth be like in that tube initially? O E 9 DO - C - 2/11/2018 11:22 PMExplanation / Answer
1) In a bacterial growth curve is a sigmoidal in shape which comprises four phases
Lag Phase- THis is an adaptive phase. During this time, the bacteria are adjusting to the environment, growing in size, synthesizing biochemicals, and storing up nutrients
Log Phase- it a growth phase, during this time cell grow at a constant rate and death rate is nearly equal to 0.
Stationary phase- This phase is characterized by no growth zone. Bacteria still grow in this phase but their growth rate is equal to the death rate. this phase occurs due to the depletion of an essential nutrient, and/or the formation of an inhibitory product such as an organic acid. therefore, the number of new cells created is limited by the remnant of growth factor and as a result, the rate of cell growth matches the rate of cell death
Death phase - this is the phase when bacteria die as death rate is higher than the growth rate. this is due to accumulation of inhibitory product such as organic acid, beyond the threshold limit and also complete depletion of aliment needed to support the growth of bacteria.
2) proportion of living cell versus death cell
in lag phase, living cell> dead cell
in log phase, living cells >> dead cells
in stationary, phase living cells = dead cells
in death phase, living cells << dead cells
3) when cells will transfer from lag phase to a sterile broth tube it will have the same sigmoidal curve as it is shown in figure
when cells will transfer from log phase to a sterile broth tube it will have the same sigmodal curve with very short lag phase compare to given figure.
when cells will transfer from stationary phase to a sterile broth tube it will have the same sigmodal curve with slightly long lag phase compare to given figure.
when cells will transfer from death phase to a sterile broth tube it will have the same sigmoidal curve with very long lag phase.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.