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Nano-Probes Stay Inside a Cell's Nucleus for Days
Roland Piquepaille writes "Researchers from the Lawrence Berkeley National Laboratory (LBL) have developed fluorescent and stable nano-probes which can stay inside a cell's nucleus for hours or even days. According to this LBL news release, this will help biologists to better understand nuclear processes that evolve slowly, such as DNA replication, genomic alterations, and cell cycle control. This research was partially based on previous investigations about quantum dots. Now, the researchers want to tailor their quantum dots, which emit different colors depending on their sizes, to check specific chemical reactions inside nuclei, such as how proteins help repair DNA after irradiation. Read more for other details and references and to see how a nano-sized probe is entering a cell's nucleus."
It's been a long time since my biology classes, but I can't think of any reaction to foreign body inside a cell (at least not in the usual way). A cell hasn't got an immune system of it's own. Of course it has systems capable of expelling foreign/toxic chemicals out of the cell (exocytosis, pinocytosis), but it is altogether different from say your body's reaction to a foreign body. So these microcrystals will probably in some way interfere with the inner working of the cell (it trying to expell it) but they do not neccessarily need to interfere with the actual working of the nucleus.
Uhhh . . . in a word, no. Sounds like the complexity and accuracy a high school biology lecture . .
Mitochodria oxidize Pyruvic acid in a series of steps to convert NAD+ to NADH. This produces CO2 and Acetyl CoA. Acetyl CoA is further oxidized in the Citric Acid Cycle producing more NADH and CO2.
What you may be thinking about is glycolysis . . . which is the breakdown of sugar (typically glucose) into pyruvic acid. This happens in the cytosol OUTSIDE the mitochodria. It is important to note that almost any carbon based molecule in the body can be converted into pyruvate and oxidized in the mitochodria (fatty acids, sugars, amino acids, some nucleic acids, etc.)
NADH is then converted into NAD+ through a mitochodria membrane to convert Adenosine Diphosphate (ADP) to Adenosine triphosphate (ATP) along an inner membrane of the mitochodria.
A more accurate restatement of your post might be:
Mitochodria oxidize pyruvate derived from sugar, fatty acids, amino acids, and other sources to produce NADH. Mitochodria also use NADH to convert ADP to ATP.
See, for instance, the quantum dot company (www.qdot.com). What is new is using a bio tag to direct the dot into the nucleus; such tags ("nuclear localiztion signals") are well known in theliteratrue for proteins, so what is new is that they took qdots and coated them with one of these signals. So, this is an addittion to the large catalog of optical probes that biologiest have.
I work in this field in graduate school and this technology is both old and new. The major problems right now are the toxicity on the cell. The actual probes can be modified or coated to exist within a cell without any major problems but when they breakdown, your body doesn't agree with some of the heavy metals that are released. As far as the word quantum goes, that only refers to the way that the electrons are confined withing the quantum dot. It is what gives the signal that you see. Safer particles are being synthesized and this field in the future will be used for drug delivery as well as real time visualization of cellular functions.