Question

1. Which of the following processes will most likely occur when you transfer a bacterial culture from 37 °C to 10 °C?

a) the bacteria will start synthesizing cholesterol
b) the bacteria will remove cholesterol from their membranes
c) the bacteria will reduce the number of unsaturated bonds in the fatty acid tails of their phospholipids
d) the bacteria will increase the synthesis of phospholipids with very long fatty acid tails and insert these into their membranes
e) the bacteria will increase the synthesis of phospholipids with unsaturated fatty acid tails and insert these into their membranes

2. Following up on question 1, which of the following best describes what would happen to a culture of yeast cells that was shifted from 37 °C to 10 °C?

a) The cells will die because their plasma membrane will be leaky
b) The cells will increase the synthesis of phospholipids with long, saturated fatty acid chains
c) The cells will increase the synthesis of phospholipids with short saturated fatty acid tails
d) The cells will insert more cholesterol into their ER membrane
e) The cells will insert more ergosterol into their plasma membrane
f) The cells will remove phospholipids with unsaturated fatty acid tails from their plasma membrane

Answer 1

Answers with Explanations:

1. Which of the following processes will most likely occur when you transfer a bacterial culture from 37 °C to 10 °C?

The answer is letter e, the bacteria will increase the synthesis of phospholipids with unsaturated fatty acid tails and insert these into their membranes.

Explanation: Bacteria are capable of surviving different types of environments with varying temperatures. When it is exposed to a low temperature, as in the situation above (from 37 °C to 10 °C), it regulates its transition phase. Th cytoplasmic membrane of organisms plays a vital role when it comes to physiological environments.

When it comes to bacteria, their membrane is primarily composed of "phospholipids." It is said that the phospholipids with unsaturated fatty acids have a transition that is lower to that of phospholipids with saturated fatty acids when it comes to temperature. Thus, the bacteria will have to increase the synthesis of phospholipids with unsaturated fatty acid tails and insert these into their membranes. This will help increase the membrane's fluidity, thus allowing it to survive in low temperatures.

2. . Following up on question 1, which of the following best describes what would happen to a culture of yeast cells that was shifted from 37 °C to 10 °C?

The answer is letter b, The cells will increase the synthesis of phospholipids with long, saturated fatty acids chains.

Explanation: The growth of yeast is affected by several factors, naming temperature as one. They are sensitive to temperature, such that they can be killed in water if it reaches a peak of 60°C.

At 10 °C, the yeast will continue its metabolic activity but with low growth rates. Its biological membrane now comes to play its part when it comes to regulation. The growth of temperature is directly related to the degree of the cell's lipid unsaturation. This means that when temperatures are lower, the saturation of lipids is low. So, the cells would most likely increase the synthesis of phospholipids with long, saturated fatty acid chains when the temperature is low.