Final answer:
It is likely to see a replacement of stearate by oleate in bacterial membranes when the culture is moved from 37°C to 25°C, as this maintains membrane fluidity in colder temperatures. E. coli is known to adapt its membrane lipid composition to ensure survival in different environmental conditions.
Step-by-step explanation:
When the bacterial culture growing at 37°C is transferred to a culture room maintained at 25°C, it is likely to observe the gradual replacement of stearate by oleate in the membrane phospholipids. This change increases the proportion of unsaturated fatty acids like oleate, which contributes to maintaining membrane fluidity at lower temperatures. The presence of unsaturated fatty acids with their “kinks” helps prevent membranes from becoming too rigid and susceptible to rupturing in a cold environment, whereas saturated fatty acids would lead to a denser and more solid membrane structure.
Organisms, including E. coli, demonstrate homeostasis by adapting their membrane lipid composition in response to environmental temperature changes. Hence, to analyze this adaptation, one would:
- Analyze the data to calculate the ratio of unsaturated (U) to saturated (S) fatty acids in the plasma membrane.
- Graph the ratio U/S versus growth temperature to visualize the relationship.
- Explain the response of E. coli to the environmental temperature by discussing the impact on membrane fluidity and organism survival at various temperatures.
Understanding the relationship between temperature and the composition of the cell membrane is crucial for many biological applications, including ensuring the correct incubation conditions for bacterial cultures in laboratory settings.