Q: Things discussed in the past couple days are finally
sinking in, and one question that has come to mind is related to the
nitrogen cycle. Your notes (and the book) have the terms "nitrate
reduction" and "denitrification". I am not clear on the difference
between nitrate reduction and denitrification. Both seem the same to
1. They can produce the same products when reduced (nitrous oxide, and then nitrogen gas).
2. They both can be seen in dissimilative pathways, except I also notice that nitrate reduction can be assimilative as well.
A: Is there a difference in the use of the terms "nitrate reduction" and "denitrification"?
Nope ... just a matter of different perspective ... when nitrate is removed from the environment (denitrification) it is done via nitrate reduction.
Q: I was studying the various links from your lecture
notes. I came across a confusing question: The website linked to
"Cyanobacteria" claims that they are the oldest fossils found at 3.5
1. How can that be possible given that they do oxygenic photsynthesis?
2. My notes say that the fossils found 3.5 Ba more resembled the purple-sulfur bacteria. This would make more sense since they do anoxygenic photosynthesis.
A: I took a look at the web page you're referring to, and you're absolutely right ... there's a problem here! At first I thought that the author of the page was just a poor writer, but careful analysis of the sentence structure makes me think the problem is that they are poorly informed. It would be correct to say that the some of the oldest known fossils appear to be filamentous bacteria with morphology similar to that of the cyanobacteria, but they wouldn't be very similar to current-day cyanobacteria if so (they would be anaerobic, for starters). You can safely ignore these people, because they are wrong on both the points you mention above before they even get out of their first paragraph. Too bad :>(
I'm sorry about this ... I'll take that link off my web page!
Thanks for bringing it to my attention :>)
Here's a timely article that relates to Environmental Applications topics that we will be discussing next Monday.
BUSH SLASHING AID FOR E.P.A. CLEANUP AT 33 TOXIC SITES
from The New York Times
WASHINGTON, June 30 The Bush administration has designated 33 toxic waste sites in 18 states for cuts in financing under the Superfund cleanup program, according to a new report to Congress by the inspector general of the Environmental Protection Agency.
The cuts, imposed because the cleanup fund is hundreds of millions of dollars short of the amount needed to keep the program on schedule, mean that work is likely to grind to a halt on some of the most seriously polluted sites in the country, confronting the surrounding communities with new uncertainty over when the work will resume, how quickly it will proceed and who will pay for it.
Among the sites that for now would receive less money in some cases, none are a manufacturing plant in Edison, N.J., where the herbicide Agent Orange was produced, several chemical plants in Florida and two old mines in Montana. The report to Congress is the first public listing by the environmental agency of where it intends to cut Superfund spending. It was provided to The New York Times by Democrats on the House Energy and Commerce Committee who oppose the cuts.
Q: Hello! I just need a clarification about the reading
assignments... if there are major topics that were not covered in
class will we be responsible for the information in detail? Or is
this additional information to help us with the subject matter and
the notes are the thing to mainly focus on?
A: I tend to test over what I present in class, Melody, so it is best to use the text as a reference.
Q: How many points do I have, and what is my current
A: Check out the Evaluation web page for the grade distribution guidelines, then check out your current points and estimated grade.
Q: What is the best way to study for this course?
A: Check out the Study Tips and do what they tell you. The tip about using writing to integrate diverse ideas and synthesize them into your own working model is my favorite. Another very helpful approach is to thoroughly familiarize yourself with the material, then discuss it with other students to help you look at it from different viewpoints to make sure you understand it and that you have not just memorized the information.
Q: Exactly how useful is the textbook to us in studying for
this class? I find it a little hard to read, and it seems like
everything we need to know can be found on the study guides. Is it
best to use the textbook as a reference?
A: The textbook is a very important reference, because it will allow you to go beyond the lectures and the study guide on many topics, thus allowing you to better develop your knowledge base and your understanding of microbiology. As I indicate on the Study Tips web page, it would be a mistake to think that memorizing the study guide is sufficient for success in this course. After you have memorized enough material to have a significant knowledge base, you need to use it as a "jumping-off" point for developing a deeper understanding of microbiology, especially from a conceptual and process-oriented viewpoint. Only when you have mastered this process will you be able to truly understand microbiology such that you can use it for the rest of your life. That, of course, is what a real education is all about. Interestingly enough, as you progress through the semester, one way to gauge your progress is to note how much easier it becomes to read the textbook. Happy synthesis and integration! Q: What will the questions be like on the exams?
A: Check out the Sample Questions for some tips and mind tweaks.