[KAJLogic]

So I got some points off (not the question wrong) for a few of these. So it seems the professor didn't want an accurate answer rather he wanted us to remember what he would say in this situation. Before I continue I want it to be known I actually like this professor and from what I can tell (and I think I am quite good at gauging human interactions) he has no animosity towards me. I am just wondering if any one on this forum can justify my professors decisions outside of it isn't the answer he is looking for. 


The first one I take issue with:

He asked, "Explain how an increase in temperature might allow an enzyme-catalyzed reaction to be MORE efficient. Also explain how an increase in temperature might make it LESS efficient.

My answer, You want molecular movement but not at the expense of the molecular structure (especially the enzyme's).



Next:

Describe TWO ways cells can alter their membrane flexibility.

 I put, the extra cellular matrix can alter flexibility as well as the amount of membrane proteins.




I think I will put just one more

Define the term Electrochemical Gradient

I put, a difference in molecular charge.

[DrCMS]

I'd give different answers to all three questions

Higher temperatures generally lead to faster reactions as more of the molecules have the required activation energy to react.  However high temperature can denature the enzymes.  Your answer is similar but does not give the whys.

I thought cell membrane flexibility would depend on the proteins involved and the cytoskeleton.  i.e. in the cell not outside it.

An electrochemical gradient is caused by a difference in the concentration of charged ions. 
You answer suggests a difference in the size/polarity of the charge rather than a difference in the number of charged species.

[Corribus]

@OP

I agree with DrCMS as well as your professor.  Your answers simply aren't detailed or clear enough to earn full points.  For example, your answer "You want molecular movement but not at the expense of the molecular structure (especially the enzyme's)" is very vague.  You mention "molecular movement" but fail to establish how this relates to reaction efficiency.  Likewise, you fail to explain how "molecular structure" relates to reaction efficiency. 

My advice to students in open ended question is to be sure you address the "why" in addition to the "what".  Yes, membrane proteins impact fluidity, but how, why and in what direction?  This is how you demonstrate adequate understanding of the material.

[Babcock_Hall]

Membrane fluidity can be altered in theory by changing the length of the carbon chains of the fatty acyl groups in membrane lipids or by changing the relative amounts of saturated to unsaturated fatty acids.  The latter effect is seen experimentally in E. coli cells cultured at different temperatures (Table 11-2, Nelson and Cox, Principles of Biochemistry, 5th ed.).  At higher temperature the ratio of unsaturated to saturated fatty acids goes down.  In eukaryotic organisms, cholesterol affects membrane fluidity, but I don't know whether the percentage ever changes.

[KAJLogic]

@DrCMS

I thought cell membrane flexibility would depend on the proteins involved and the cytoskeleton.  i.e. in the cell not outside it.

That isn't the answer he wanted he was moving towards what Babcock hall said; in the professors eye's both me and you were talking about inconsequential changes.

An electrochemical gradient is caused by a difference in the concentration of charged ions. 
You answer suggests a difference in the size/polarity of the charge rather than a difference in the number of charged species.

In what way does, difference in molecular charge, imply anything but a electrochemical gradient?

My advice to students in open ended question is to be sure you address the "why" in addition to the "what".  Yes, membrane proteins impact fluidity, but how, why and in what direction?  This is how you demonstrate adequate understanding of the material.

A correct response to that question that would receive full points is: Saturated or unsaturated fatty acids and cholesterol amount on the membrane. That to you is answering the why? He did not want us to get into answering the why because with the volume of questions it would have taken far too long.

So to recap the only question I could (arguably) have taken a less desirable answer was the fluidity question. As far as being vague I answered the questions that were given. If your just accusing me of not explaining enough I could do the same to anyone who tries to answer these questions, because vague is relative and has no discernible value. This all goes back to the real idea here am I to assume he is trying to lead me to a specific response, or rather, am I to assume he wants me to dig into my knowledge of the cell to spit out an accurate response?

[billnotgatez]

Is there a specific textbook being used in the course?
And does the professor reference it

[KAJLogic]

Yes on both accounts.

[Babcock_Hall]

With respect to membrane fluidity, some cells clearly have the capability to alter the fatty acyl group composition of their membranes in response to temperature.  The proteins that are there have functions, and I cannot see how one could add to or subtract from their number as a response to temperature without other consequences.

What do you mean when you say molecular charge?

[KAJLogic]

I agree babcock looking back your answer makes more sense, but his question wasn't what can a cell do to regulate membrane fluidity. Molecular charge being the charge or a molecules corresponding atoms.

[billnotgatez]

I am sorry for not making it clear
Could we have the titles and authors of the text

[KAJLogic]

Reece Campbell Biology 9th.

[Corribus]

As far as being vague I answered the questions that were given. If your just accusing me of not explaining enough I could do the same to anyone who tries to answer these questions, because vague is relative and has no discernible value.

I am not accusing you of anything. I'm telling you, as someone who has taught college level courses, graded and written exams, and passed many exams, and because you asked, that in my opinion your answers are extremely vague and do not demonstrate mastery of the material, and I would certainly not have given you full credit.  Every professor grades an open ended question differently, of course - because the "degree of correctness" of an answer to such a question is ipso facto subjective.  If you really want to know why you didn't get full credit, the only person who can give you a truly accurate answer is the person who did the grading.  Aside from that, there's no need to be defensive, and stubbornly insisting that your answers are satisfactory - especially out of a fatuous appeal to relativism - isn't going to help you learn how to get better scores on your tests.

[KAJLogic]

I am not accusing you of anything. I'm telling you, as someone who has taught college level courses, graded and written exams, and passed many exams, and because you asked, that in my opinion your answers are extremely vague and do not demonstrate mastery of the material, and I would certainly not have given you full credit.  Every professor grades an open ended question differently, of course - because the "degree of correctness" of an answer to such a question is ipso facto subjective.  If you really want to know why you didn't get full credit, the only person who can give you a truly accurate answer is the person who did the grading.  Aside from that, there's no need to be defensive, and stubbornly insisting that your answers are satisfactory - especially out of a fatuous appeal to relativism - isn't going to help you learn how to get better scores on your tests.

I was never on the defensive I started this thread letting everyone know I have nothing against my professor nor him me. I fail to see how my argument is trivial. What is the point were trying to get to here me getting good scores is that how reality works, or rather a Socratic understanding of the material. Latin, no matter how eloquently used, isn't going to help you get around this simple fact.