Question

In humans and many other animals, triacylglycerols are the major form of stored energy. Which of the following statements describe the differences between triacylglycerols and glucose?

A. Glucose is highly redox reactive and therefore must be stored as glycogen to protect the cell.
B. Triacylglycerols are more soluble in water than glucose and therefore easier to break down in the cell.
C. Fatty acids are at a higher reduction state than glucose.
D. Fatty acids yield more energy than glucose for the same number of carbons upon oxidation.

Answer 1

Fatty acids in triacylglycerols are at a higher reduction state than glucose and yield more energy upon oxidation. Glycogen is the storage form of glucose, and triacylglycerols are less soluble in water than glucose.

Step-by-step explanation:

In humans and many other animals, triacylglycerols are the major form of stored energy. Comparing triacylglycerols and glucose, the statement "C. Fatty acids are at a higher reduction state than glucose" is accurate because fatty acids in triacylglycerols have many hydrogen atoms that can be used during oxidation to produce energy. Additionally, the statement "D. Fatty acids yield more energy than glucose for the same number of carbons upon oxidation" is also correct, as fatty acids can produce more energy per carbon atom when they are fully oxidized through beta-oxidation and the citric acid cycle, compared to glucose.

The incorrect statements are A and B. Glucose indeed needs to be stored as glycogen, not because it's highly redox reactive, but to maintain osmotic balance and provide a readily mobilizable form of energy. Triacylglycerols are less soluble in water than glucose, which is why cells store them as droplets, separate from the aqueous environment inside cells.