How many water molecules are produced during the formation of a triglyceride from fatty acids and glycerol?

Question

A.  0
B.  1
C.  2
D.  3
E.  4

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

Gather Content
· What do you know about triglycerides? How does it relate to the question?

Consider Possibilities  
· What other information is related to the question? Which information is most useful?
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

D.  3

Clarify Question
· What is the key concept addressed by the question?
        o The question asks about the number of water molecules produced in a dehydration synthesis reaction.
· What type of thinking is required?
        o You are being asked to analyze a reaction to predict the number of water molecules produced.
· What key words does the question contain and what do they mean?
        o Formation of a triglyceride from fatty acids and glycerol – a triglyceride contains a glycerol backbone with three fatty acids.

Gather Content
· What do you know about triglycerides? How does it relate to the question?
        o Glycerol is a 3 carbon sugar with 3 hydroxyl (OH) groups.  Each of these OH groups reacts with a fatty acid, forming a triglyceride.  In each of these steps a water molecule is released in a dehydration synthesis reaction.  It is dehydration because water is released, it is a synthesis, because you are making triglyceride from glycerol and fatty acids.

Consider Possibilities  
· What other information is related to the question? Which information is most useful?
        o The “tri” in triglyceride refers to the three fatty acids attached to the glycerol.
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Because fatty acids are attached to glycerol through a dehydration reaction, one water molecule is released with each reaction.  Three fatty acids are attached to glycerol to form one triglyceride, so three water molecules would be released.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked you to analyze a reaction to predict the number of water molecules produced. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that this is a dehydration synthesis reaction?  Did you recall that three fatty acids are added to the glycerol?  Did you understand that one water molecule would be released as each fatty acid was attached to glycerol?