Q: Which of the following equations correctly represents the formation of a triacylglycerol molecule?

$\text{Glycerol} + 3\ \text{Fatty Acids} \xrightarrow{\text{Dehydration}} \text{Triacylglycerol} + 3\ \text{H}_2\text{O}$

Question 1

Which of the following best explains why lipids are efficient molecules for energy storage in cells?

Accepted Answer

They contain a high proportion of C-H bonds, which release energy when oxidized.

Question 2

A patient is diagnosed with a disorder affecting the structure of their cell membranes. Which class of lipids is most likely involved in this condition?

Accepted Answer

Phospholipids

Question 3

Which structural feature distinguishes unsaturated fatty acids from saturated fatty acids?

Accepted Answer

Presence of one or more double bonds between carbon atoms

Question 4

Which of the following equations correctly represents the formation of a triacylglycerol molecule?

Accepted Answer

$	ext{Glycerol} + 3\ 	ext{Fatty Acids} \xrightarrow{	ext{Dehydration}} 	ext{Triacylglycerol} + 3\ 	ext{H}_2	ext{O}$

Question 5

Which lipid class is characterized by a four-ring hydrocarbon skeleton?

Accepted Answer

Steroids

Question 6

A researcher isolates a lipid containing a carbohydrate chain attached to a sphingosine backbone. Which class of lipid is this?

Accepted Answer

Glycolipid

Question 7

Which of the following best describes the amphipathic nature of phospholipids?

Accepted Answer

They have both hydrophilic (polar) heads and hydrophobic (nonpolar) tails.

Question 8

Which of the following is NOT a function of lipids in biological systems?

Accepted Answer

Catalyzing biochemical reactions

Question 9

A mutation prevents the formation of ester linkages in a cell. Which lipid class would be most directly affected?

Accepted Answer

Triacylglycerols

Question 10

Which of the following statements about terpenes is correct?

Accepted Answer

They are constructed from isoprene units and are precursors to vitamins such as vitamin A.

Question 11

Which of the following best explains why unsaturated fatty acids tend to be liquid at room temperature?

Accepted Answer

The presence of double bonds introduces kinks, preventing tight packing of molecules.

Question 12

A cell is observed to have a high concentration of sphingolipids. Which of the following is a likely function of these molecules?

Accepted Answer

Cell recognition and signaling in the nervous system

Question 13

Which of the following best describes the general formula for a saturated fatty acid?

Accepted Answer

$\mathrm{C}_n\mathrm{H}_{2n+1}\mathrm{COOH}$

Question 14

Which of the following scenarios would most likely result in a decrease in membrane fluidity?

Accepted Answer

An increase in the proportion of saturated fatty acids in phospholipids

Question 15

Which of the following is a correct match between a lipid class and its function?

Accepted Answer

Steroids – signaling molecules such as hormones

Question 16

A scientist is studying a molecule with the following structure: a glycerol backbone, two fatty acids, and a phosphate group. Which type of lipid is this?

Accepted Answer

Phospholipid

Question 17

Which of the following best describes the role of cholesterol in animal cell membranes?

Accepted Answer

It modulates membrane fluidity by preventing tight packing of phospholipids at low temperatures.

Question 18

Which of the following is a distinguishing feature of glycolipids compared to phospholipids?

Accepted Answer

Glycolipids contain a carbohydrate chain attached to the lipid.

Biological Macromolecules: Lipids

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