CharonY

This is depends largely on the context of the talk. In lectures it is ok, in short presentations (as indicated above) it is a waste of time and generally frowned upon. Unless you have a brilliant hook of sorts. But even then a rhetorical question may be more appropriate.

Well, again, contagious and pathogenic are two different aspects. Almost all bacteria (except extreme specialists) can spread to a given extent, and are therefore by definitionem contagious. Yet they do not necessarily cause harm. If your hand is sterile and you touch any surface you will get bacteria on it. There, transmittance happened. You won't usually get sick, though. The bacteria just has to be able to grow on the given surface (in this case, skin). And also again, there is hardly anything that can be considered a pathogenicity factor that is shared by all pathogens (if we want to limit it to diseases). The routes of infection and persistence that bacteria employ are simply too varied. Of course one can have a bit of a circular argument instead. Pathogenic bacteria share traits that enable them to infect, overcome immune response, and cause disease . I think one of the few common things I can think of are toxins of some sorts, though they are very diverse in nature (and are just commonly labeled toxins due to their ability to cause harm) and not all pathogens are known to produce any of them.

OK, that makes more sense. Note that I am not an expert in this field, but assuming that he/she meant an antibody staining after fixation, there is no real way to confirm origin as (afaik) the recycled proteins do not undergo any specific and detectable modifications. Additional experiments are needed and may either include disruption of recycling pathways or tracking the internalization of (labeled) surface proteins. For instance, if the protein in question is not stably localized in the membrane, one could label it shortly (e.g. with an antibody), wait until it vanishes and check for the re-appearance of the antibody on the surface after re-incubation.

Yupp, precisely.

Well, in a way by trying to be vague you inadvertently made a false statement. Ie "combining" molecules usually would be a reference to anabolic pathways, which is the opposite to what is happening with glucose. It would be more correct if you had worded it as "breaking down"- both are not normally used, but for a layman they make somehow sense and are not really wrong. I just had to point that out as I was unable to pass up the irony in your post

Actually I prefer to have everything on a slide, but it has to be very short so I can skim through it in a few seconds and then concentrate on the talk (as part of the audience) or to remind me what I am going to talk about and in which context (as speaker). Personally I dislike things popping up. I prefer a slide to be static (with very few exceptions). Talk to the audience and do not stare on your screen, notes, whatever. Rather use the points on the slide to remind you what you want to talk about. Practice your talk! Stay in time and allow some for discussion. As a student or sometimes even postdoc showing nerves is expected, just do not overdo it.

Well, if we talk about proper wording, glucose does not yield ATP by combining it with other molecules... To be precise, the yield varies with how the complete oxidation is conducted and how the created reduction equivalents are used for oxidative phosphorylation. The substrate level gain is easy to assess, however the oxidative phosphorylation is based on estimates as the ATP generation is based on the creation of a proton gradient to power the ATP synthetase. The often cited 36 (or even 38) ATP is likely a bit of an overestimation.

Also the context of the question is important. It sounds like a highschool question, which expect a dumbed down answer. Even for that the question is pretty lousy, though. Contagious just means transmissible (and not, as iNow correctly mentioned, the means of transmission). Essentially all bacteria that are able to live on a given vector are transmissible. This includes non-pathogenic bacteria. Just think about it. How do you get your normal bacterial flora? Now if the question is what are common characteristics of contagious pathogenic bacteria, things are complicated. Short answer is that there is likely no common trait exclusively shared by all pathogens that are not present in non-pathogenic one. Many pathogens are specialists in one way or another and quite often pathogenicity factors are elements that are also found in non-pathogenic bacteria, but it makes them pathogenic in conjunctions with yet another factor.

Sorry, maybe it is just the lack of caffeine in my blood system, but you are not making terrible sense to me right now. First you started off with (my bold) and now it is not based on microscopic observation but based on... what? Also the main question is still not clear to me. Evidence for e.g. localization can be based on different techniques, of which some are considered more definite than others. Thus the actual technique in question is significant.

It is true, though.

First, how did you detect the protein in the first place? Fluorescence tagging? Antibodies? Second, what precisely is your question? Whether it is a membrane associated or integral membrane protein versus co-purified membrane fraction?

You would only get around a third of all characters in an average newspaper, though.

Uh Pangloss? Being literate usually requires the knowledge of 3 to 4000 characters.

Use the BLAST programs. Generally searching for 100% matches has only limited value in real analyzes, hence alignment programs as BLAST are used.

Well essentially the answer is there, a virus is a mobile genetic element requiring a cell to propagate. Hence, it cannot predate cells.

Actually it is always the complementary base. That is A pairs with T (or U) and G with C (and vice versa). So if the DNA sequence on the strand to be transcribed ist ACTG the RNA sequence would read UGAC. The whole system works unidirectional (5' to 3') so towards the 5' is considered up and the reverse downstream. Also in addition to the actual start codon the mRNA also contains more sequences that are not transcribed into a protein but are necessary for transcription (i.e. ribosomal binding site).

The first thing you need to get is that RNA is just transcribed DNA. Ie the sequence is complementary to the DNA strand getting transcribed. Now, the promoter is a specific DNA sequence upstream of the actual part of the DNA that gets transcribed into RNA. Essentially it is a regulatory element to which an enzyme, the DNA dependent RNA polymerase, together with certain other factors, bind in order to create the complex that does the actual transcription from DNA to RNA. It is often also the target for regulatory elements that enhance or reduce the binding efficiency of the complex and thus regulate the transcription rate.

Actually you should just start off reading a few articles (even Wikipedia) about DNA and RNA and the very basics. The problem is that you base your assumptions on a very inaccurate guesstimations and any info given right now will probably just lead to confusion at best.

I am just wondering, does it make sense here to make a distinction of natural science and other sciences? In most discussion here science is equaled with natural sciences. Obviously there other branches including the humanities which are also claimed to be sciences but often use different methodologies. And there are gray areas in which those overlap, for instance psychology and in some cases (e.g. case studies) even medical sciences.

Precisely. Natural selection is not something that has a function. It is just something that happens. The outcome is just that different phenotypes happen to have different reproductive success. And in retrospect we call whatever happened, natural selection. Incidentally it also explains why immortality is not universal. A simplified view is that more varied and complex the tissue of an organism becomes the harder it is to control cell replication in a way that avoids negative effects (e.g. as manifested by cancer). Hydras as well as unicellular organisms have a very simple arrangement and have little trouble to be virtually immortal. Yet the complex structures of e.g mammals allows them to use different ecological niches than the simple organisms. Longevity also does not increase fitness, if the time frame of possible reproductions is not equally enhanced. Except, of course, in social animals and maybe even some other situations in which one promotes the fitness of closely related individuals.

Nope. The only measure of fitness is the amount of offspring you create that in turn are able to create offspring. Also you will have to consider that direct competitors are usually those that try to fill the same ecological niche and not those that hunt each other. If an organism utilizes the niche more efficiently by and creates more offspring they are fitter, regardless whether they are stronger or smarter. Cockroaches are a prototypical example. They are hardly the smartest critters on earth and clearly do not overpower much, but if they beat the heck out of a lot of animals in filling (urban) ecological niches.

It would help if you could state what you are interested in and what type of macromolecules.

Actually I think stupid in this regard is a good choice as it reflects the transition from student to scientist. As a student there are (apparently) answers to all questions. Or at least you job is more or less to memorize them. However this stops when you start doing science. You think it is daunting and a challenge if you already stopped being in the frame of mind of a student. But if you still are, you will assume (and I can tell you, a lot of students do) that there has to be an (easy) solution. But not getting the answers, which they assume that they should be around, makes them feel... well, stupid.

Though it would be more accurate to call them social democratic as socialists may be interpreted in the Marxian sense (you know, dictatorship of the proletariat). In the US the terminology is often fuzzzy in that regard.

Also by far not all possible chemical reactions have been mapped out yet. Chemistry is not only about identifying elements, but more importantly it deals with interactions.