Question

List two differences you would expect to see in the composition of lipids in the E. coli membrane when the cells are incubated at 25 ∘C compared to incubation at 37 ∘C.Match the words below to the appropriate blanks in the sentences below it. Make certain each sentence is complete before submitting your answer1 shorter fatty acids2 longer fatty acids3 trans4 cis1. The membranes of cells grown at 25 °C would have _____ with a greater number of ______double bonds compared to the membranes of cells grown at 37 °C.

Answer 1

The membranes of cells grown at 25 °C would have shorter fatty acids with a greater number of cis double bonds compared to the membranes of cells grown at 37 °C.

Step-by-step explanation:

E. coli have developed a response to heat stress called homeoviscous adaptation — they can keep the same fluidity of their cell membranes over a range of temperatures.

They do this by changing the makeup of their cell lipids. At lower temperatures, their membranes have shorter fatty acids with more cis double bonds.

This is a successful strategy because

• Shorter fatty acids have lower melting points and
• cis double bonds hinder efficient packing in a crystal. The smaller London dispersion forces keep the substances liquid and increase membrane fluidity at lower temperatures.