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From: shahn@hstbme.mit.edu (Sam Hahn)
Newsgroups: sci.bio
Subject: Re: Quiz time
Message-ID: <6552@husc6.harvard.edu>
Date: 26 Apr 91 21:19:28 GMT
References: <1991Apr24.134105.25827@pa.dec.com>
Sender: news@husc6.harvard.edu
Organization: Decision Systems Group
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The majority of these questions are very poorly worded and could be 
interpreted in a number of ways. Let me play the "devil's advocate" and 
answer some of these questions nonconventionally.

>  A "high-energy bond"
>   a) absorbs a large amount of free energy when the phosphate group is
>      attached during hydrolysis.
>   b) is formed when ATP is hydrolyzed to ADP and one phosphate group
>   c) is usually found in each glucose molecule; that is why glucose is
>      chosen as the starting point for glycolysis.
>   d) none of the above
(D) is the correct answer. (A) is wrong because phosphate groups are not 
attached during HYDROLYSIS. (B) is wrong for the same reason as (A). (C) 
is wrong because more than a single high energy bond is present in 
glucose...furthermore I'm not sure if glucose even contains "high energy" 
bonds. Oxidative phosphorylation derives energy from glucose not because 
it absorbs the energy of bond hydrolysis but because it uses redox 
reactions to alter chemical composition. I'll have to look in my old 
organic chemistry book to see what the bond energy is for C-C and C-O and 
O-H bonds.

> When NAD combines with hydrogen, the NAD is
> 
>   a) reduced  b) oxidized  c) phosphorylated  d) denatured  e) none of 
these
(A) is the answer. The reaction is really NAD+ plus H- yields NADH if I 
recall correctly. What you are really doing is adding one proton and two 
electrons. The net effect is the addition of one electron or the REDUCTION 
of oxidation state. IF THE REACTION IS TAKEN TO BE LITERALLY: NAD plus H 
yields NADH the answer would be (E) since no reduction or oxidation has 
taken place. Clearly no phosphorylation or denaturation has occurred.

> The oxygen released in photosynthesis comes from
>   a) carbon dioxide  b) glucose  c) ribulose biphosphate 
>   d) water  e) atmospheric oxygen
Oh boy, now you are really stretching my recall: Ok, I recall that in 
oxidative respiration, the H20 that is generated comes from atmospheric 
oxygen. Therefore, working in reverse, the oxygen released from 
photosynthesis must come from water or (D).

> Which of the following has the most energy?
>   a) AMP  b) ADP  c) ATP  d) glucose  e) NADPH
BAD BAD BAD BAD question. What does that mean? Does it mean which has the 
most readily accesible energy? Most chemical energy? My interpretation 
would be to use the old E=MC2 routine and say that the largest molecule 
has the most energy. I don't remember the structure of NADPH but I think 
ATP is still larger so I will say (C).

What where the "correct" answers?

Sam