Question

"Homeoviscous adaptation” is the process whereby bacteria adjust the fatty-acid composition of their phospholipids to maintain constant membrane fluidity when incubated at non-standard temperatures. Which of the following would describe the lipid content of cells cultured at 30°C compared with control cells incubated at 23°C?

a. Fatty acids would be more polyunsaturated than in control cells

b. Fatty acids would be, on the average, shorter than in control cells

C. Fatty acids would be identical in composition to those in control cells

D. Fatty acids would have fewer double bonds, than those in control cells

E. Fatty acid content would be similar, but the amount of PE would be decreased

Answer 1

QUESTION-1

ANSWER-D.

Homeoviscous adaptation” is the process whereby bacteria adjust the fatty-acid composition of their phospholipids to maintain constant membrane fluidity when incubated at non-standard temperatures.

The following would describe the lipid content of cells cultured at 30°C compared with control cells incubated at 23°C-

D. Fatty acids would have fewer double bonds, than those in control cells.

EXPLANATION

• Unsaturated phospholipids are liquid at room temperature.
• Saturated phospholipids have no double bonds in them while unsaturated lipids have.
• Here the bacteria are cultured at a higher temperature than the control cells.
• So the bacterial cell would increase their saturated lipid content in order to save themselves.
• So there will be fewer doubles bonds as the saturation level goes up.

GOOD LUCK.