Biosynthetic reactions

[whawha]

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This is a question from ADA sample practice test

Q. As far as their products are concerned,
all biosynthetic reactions in living cells
result in,

A. a more ordered state, therefore a
decrease in entropy.

B. a more ordered state, therefore an
increase in entropy.

C. energy released in the form of ATP.

D. energy made available for motion.

E. a more ordered state with no
entropy change.

Can somebody explain why the answer is A...? Isn't carbohydrate breaking down into smaller molecules in biosynthetic reactions...? Thank you for your time guys!!!!

 

[bennijai]

Biosynthesis is the formation of complex molecules from simpler ones, which leads to to a decrease in entropy = more ordered state.

But cellular respiration is actually an increase in entropy I believe...hm I'm stumped too..

 

[Extirpator]

plain and simple, biosynthesis is by definition the formation of more complex molecules. so yes, choice A is correct

and as far as respiration goes... the question is only asking about products formed, so yes, as far as I know it is also decreasing entropy

 

[Extirpator]

Isn't carbohydrate breaking down into smaller molecules in biosynthetic reactions...?

breaking down a molecule is not synthesis

 

[bennijai]

That makes sense. Thanks.