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Researchers Enable Mice To Exhale Fat
destinyland writes "UCLA researchers made a startling discovery: genetic alterations enable mice to convert fat into carbon dioxide.
Mammals digest fats differently than bacteria — so researchers introduced bacteria genes into mouse livers, and 'the excess fat was literally released into thin air.' (One researcher calls it 'an unconventional idea which we borrowed from plants and bacteria.') The research potentially could help treat serious medical conditions including diabetes, heart disease — and of course, obesity."
Why do people think that CO2 = bad? There is a natural carbon cycle. CO2 goes into the air, plants breath it in and breath out O2 while turning the carbon into sugar. Animals eat the plants (and other animals) and use the bonds in molecules containing carbon as a storage for energy. As they use the energy, the carbon goes back into the atmosphere. When things are in relative equilibrium, everything is fine.
The problem with fossil fuels is that there used to be a lot more carbon in the atmosphere, which was absorbed by plants which died and took the carbon with them. When we burn fossil fuels, we are re-releasing this carbon into the atmosphere, changing the balance of things. Except for deforestation and burning of fossil fuels, most other CO2 related activities don't actually change the overall amount of carbon in play. There is no need to be alarmist about this.
The problem with cars running on gasoline is that the carbon in the carbon dioxide they emit used to be stored deep underground. Once it is emitted into the atmosphere as carbon dioxide, about half of it will remain for hundreds of years, thus increasing the concentration of carbon dioxide in the atmosphere.
This is as opposed to the carbon in the carbon dioxide you exhale, which came from plants. The plants got the carbon from carbon dioxide in the atmosphere. Thus, exhaling carbon dioxide does not cause a increase in the concentration of carbon dioxide in the atmosphere.
The carbon cycle... learn it, live it, love it!
What a fool believes, he sees, no wise man has the power to reason away.
I know many fat people who go days on in eating less than a 120lb person, maybe even losing the weight, only to be broken by one binge and rapidly going back to their old ways.
That's because they are doing it wrong. They need to eat exactly what a person of their size should be eating or a teeny bit less, their body will naturally approach the correct weight with a bit of exercise thrown in. By going so they almost certainly binge because their body thinks it is starving.
Yes, this takes. It also works.
Ugh. I get tired of having to explain this. You'd think it'd stick the first dozen times or so, and I wouldn't have to keep repeating myself.
The CO2 from your breath is not the problem. The CO2 from your tailpipe is.
The reason is their source. Carbon from food is ultimately bound via photosynthesis; you either eat the plants or eat the animals that eat the plants. Photosynthesis removes free CO2 from the air and binds the carbon, releasing the oxygen. Any high school student can tell you this.
Every last ounce of CO2 coming out of your mouth, right now as you're reading this, was previously bound up as food, which was living tissue once, which (directly or indirectly) grew via taking CO2 out of the air. It's a closed cycle. Exhaling more CO2 will not result in a net increase in the carbon cycle.
Your tailpipe is different. The hydrocarbons you're burning come from fossil fuels, which have been sequestered from the atmosphere for the past few million years. Burning them does add a net amount of CO2 to the carbon cycle.
Climate change is not about what's in the air, it's about what's no longer in the ground. This is why Biofuels are a solution - the IC engine can be totally identical to one running on fossil fuels, but the hydrocarbons are grown rather than mined.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
*sigh*
Lipolysis -> Beta Oxidation -> Acetyl-COA -> TCA Cycle -> NADH/FADH -> ETC -> ATP -> CO2
It's completely natural and spontaneous in the absence of excess blood sugar.
Well, if I understand what's going on in this process, fat metabolism is occurring because the mammalian cells given the glyoxylate shunt genes don't know how to use them "properly." That is to say, plants, bacteria, and fungi use the shunt to turn fat stores into sugars. A major reason for doing this is because they need to build polysaccharide cell walls. We don't have these, so apparently if we have access to the glyoxylate shunt, we run through it, but get nothing out of it. Indeed, less than nothing- to make the dreaded car analogy, it's like sort of like the hit in fuel economy you take by driving with the air conditioner on- your fuel is powering a second motor, but it's one that doesn't contribute to the car's motion.
In terms of energy usage, the glyoxylate shunt is one of those shortcuts that turn out to take longer in the end- isocitrate molecules that take the detour are broken apart at a net energy cost, then the glyoxylate formed grabs an acetyl-CoA that could have gone to a more productive use, and then returns to the beginning of the Krebs cycle, having accomplished nothing. The shunt steers away from a couple of highly energetically favorable reactions of the Krebs cycle, and runs through one that costs energy.
The Krebs cycle, the metabolic engine, ultimately has to turn more times to produce the same amount of energy, causing it to demand more fuel in the form of acetyl-CoA. In order to meet this need, your body turns to a particularly rich source of acetyl-CoA: the beta-oxidation of fatty acids. To finally answer the parent's first question, this is where negative feedback that regulates the breakdown of fats is likely to take place. You have an enzyme called acetyl-CoA carboxylase whose activity promotes biosynthesis of fat. As the name suggests, the enzyme adds a carboxylate group to acetyl-CoA to make malonyl-CoA, a compound which is a building block of fatty acids, as well as an inhibitor of enzymes that break down fats. If you run low on fats, acetyl-CoA carboxylase should act to prevent further fat metabolism, and promote the production of more. This will hopefully result in an equilibrium between fat synthesis and fat breakdown. I say hopefully because these tidy feedback loops do not always work as well in practice, which is why we have metabolic disorders in the first place.
To answer the parent's second question, genetic modifications that correctly integrate into the host genome can generally be expected to be permanent, and spread through dividing cells. Of course, in the lab, you can add genes into an embryo of very few cells, and expect that as an adult, virtually every cell will have the genes, and even expect that the genes will be passed on to offspring. To add genes to a developed organism however involves infecting cells with a vector (usually a modified virus) that carries the genes. It is unlikely that all cells will be infected, and that all infected cells will properly integrate the foreign genes into the genome, and extremely unlikely that the genes would infect germ-line cells and be passed on. The most likely outcome would be a mosaic individual, of whose cells only some contain the foreign genes.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
Quite literally, we're enhancing our crop yields by burning fossil fuels. It's a minute increase in CO2, and I do mean very small. When compared with all greenhouse gases, it's not even background noise... Fossil fuels do not add to the green house gases in the atmosphere in amounts that we can even measure.
I take it you aren't a scientist? The increase in co2 is a measurable, real increase. There are physicists who measure the atmospheric carbon dioxide levels with great accuracy. Why do you think that that this is not possible?
By their own accords, those who want to see greenhouse gases curtailed, are only talking about 1/20th of a degree in terms of climate change. That number is probably being generous.
Did you miss the G8 meeting a few days ago where the politicians agreed to try and limit warming to 2 degrees? Who are these serious climatologists who predict warming of only 1/20th a degree? Certainly not the IPCC reports.
Increased CO2 = Bigger, better, healthier plant life. Which will equate to more available food for the human population.
Perhaps you would like to study the atmosphere and foliation of Mars to see where this argument fails?
The numbers supporting a huge campaign to combat global climate change just simply do not add up. I hate this issue, because so many people do not look at the numbers, and believe the FUD that we've been taught since we were children. I too believed all of it, up until a couple of years ago. I took a good long look at the numbers, what was being said. Low and behold, I made my own decision, and every time I hear combating carbon emissions, well let's just say whoever said it goes down a few levels on my credibility meter.
Sounds like you've been drinking the "kool-aide", in your magical universe where we can release large amounts of a previously sequestered greenhouse gas into the atmosphere and it has no effect.