Warm Up 2 ... From Prions to Oreos!

QUESTION 1: In your own words, what are prions, and how do they cause fatal brain diseases?

From Beth: q1: A prion is a messed up protein type thing that causes diseases by infecting normal proteins. At least that is what I am getting out of the reading. I don't really understand it.

From Mitzie: q1: Prions are a bad protien that can be deadly. Prions cause fatal brain diseases by tricking the noraml protiens into folding like they do. This is somewhat of a domino effect, when one decides to flip, they all seem to want to change. After the bad protiens, prions, get the good ones to flip they then get stuck in the brain which causes damage.

From Shifty-Eyed Swindler: q1: Prions are abnormal protein that possess the capability to re-arrange the structure of normal proteins. The re-arranged proteins disrupt the brain. This results in literal "dead chunks" of the brain. Since prions are not affected by heat or chemicals, it is impossible for the victim to recover...and their brain slowly deteriorates.

From jmj: q1: Prions are infectious particles, also known as abnormal proteins. These abnormal proteins 'take over' healthy proteins in the brain, literally converting them into 'clone' abnormal protein. These abnormal proteins group together into clumps or clusters of infected proteins, thus eventually 'taking charge' of the brain. They are also able to 'reproduce' with out having to have DNA to form new proteins, thus they are able to reproduce very rapidly with little effort. This is how they spread and also how come they are so fatal. I would presume, though I do not have enough information to be certain, that without healthy proteins in the brain, there is the inability for healthy brain functioning. These prions would eventually take over the brain completely, thus stopping brain activity entirely. In animals they cause diseases such as Scrapie and Bovine Spongiform Encephalopathy (BSE, in humans, Creutzfeld-Jacob Disease and Kuru.

From echo: q1: ...What I don't understand about prions is how an abnormally folded protein causes so much damage--what is it about this 'folding' that is so harmful?

Note from Dr. Marrs : The shape of a protein is VERY important to its function!! With prion diseases, much more research needs to be done; but a study in October 2003 reported that that the process of converting PrP-c to PrP-sc might produce a toxic product or may deplete a that is crucial to brain-cell survival...ie we still don't know a lot!

QUESTION 2: Starch (like bread, pasta) is a glucose polymer that gives us energy, but cellulose, an almost identical glucose polymer, is indigestible. Why do you think that ONE of these almost identical molecules can be digested, while the other can't? Why is cellulose (non-nutritive and indigestible) a very necessary part of our diet?

From Star: q2: A starch is a-glucose that provides our body with energy by converting it to glucose. Cellulose is b-glucose which is indigestable because it provides structural support. QUESTION: Since we don't eat wood, paper, cotton, or insects (well hopefully most of us!), I was wondering how we get this b-glucose in our diet? (besides celery)?

From WL: 2: Both cellulose and starch are both made up of glucose, but differ in their covalent bonding units. Cellulose is bonded in such a way that it is very stable and therefore difficult to be digested by most enzymes. Starch has a very unstable bonding pattern that makes it easily broken down by enzymes. The vegetable and fruit groups are essential parts of our diets, and both of these as well as whole grains, and beans are plants that require cellulose for structural support. When we eat these food groups, we swallow cellulose, but because it is indigestible, it passes through our bodies harmlessly.

From Nicole: q2: I honestly don't know because I could not find the answer anywhere. It does not make sense that a very necessary part of our diet could be non-nutritive and indigestible. How do we get this part of our diet if we cannot digest it? This is quite confusing to me. I was thinking that if you just ate bread and pasta to get the glucose polymer for energy, that it would possibly be okay that we could not digest the cellulost that we need so much. I figured this because the two are so close that they are almost identical. Could you provide feedback regarding this question and cover it in class this week? Please and thank you.

From Jess: q2: In C101 (Chemisty) we are learning about how small changes in atoms/ions can make a large change in the outcome. Such as one form of Chloride is deadly but take away an electron and add sodium then you have salt. Small changes in the make up can lead to very different outcomes.

From Cas: q2: The reason that one of these can be digested and the other can't has to do with bonding. When structures bond in different ways, they form different shapes, some of which ar emore stable than others. In this example, starches form a type of spiral shape, and cellulose forms a straighter shape. The straighter shape of cellulose is more stable then the spiral shape of starchs, and is therefore harder to break down. Cellulose is impossible for humans to break down, and just passes through our digestive systems. The only reason I could really think of for cellulose is that maybe it keeps things moving along down there?

QUESTION 3: Trans fats found in hydrogenated oils have been in the news a lot lately, and have been increasingly implicated in development of heart disease. Why do large food manufacturers like Kraft prefer to use partially hydrogenated oil when baking cookies, cakes, and crackers?

From Dave: q3: Because despite the fact that if everyone dies off from eating their products they will have no customers left, large food conglomorates like Kraft think that preserving shelf life is more important than having a living customer base. Ouch!

From sap: q3: Because the hydrogenated oil helps keep the food fresher by increasing the shelf life. Too bad the side effect is an increase in heart disease.

From Sally: q3: Large food manufacturers us partially hydrogenated oil because it helps the product to keep shelf life longer. The article says that with these "trans fats" crackers can stay fresh and crispy for years. It helps so they can produce more at once and they don't have to stay on a constant schedule. Food can be prepared quick and will stay fresh longer so that it isn't wasted and stores stay in stock longer.

From LG: q3: Trans fats are man-made or processed fats, which are made from a liquid oil. When you add hydrogen to liquid vegetable oil and then add pressure, the result is a stiffer fat, for example, like the fat found in a can of Crisco. Many corporations like Kraft use trans fats because the cause products to last longer on the shelves of grocery stores helping them save money by cutting food cost.

Note from Dr. Marrs: Food companies, especially Kraft Foods NA, are working improve the nutritional profiles of their products, as the current low-carb / low-fat, high diabetes / high obesity consumer market is deciding with their debit cards to purchase less of these products: See today's news: Kraft 6000 jobs crunch: What will happen to Oscar Meyer weenies, Velveeta, Ritz crackers, and of course Oreos!?

In addition, Kraft and other food companies are very sensitive to the legal/medical implications of what they put into their products...because they are concerned about your health, of course..: ) !! For more on options how companies are improving fats and oils for food production, read: Fats and Oils 2000: Challenges and Opportunities)

QUESTION 4 (optional): What do you think of the recent lawsuits about the dangers of trans fats in snack foods? (See "Lawyer Sues Kraft for selling Oreos to Kids"). Comment from any perspective you choose...Kraft, a parent, a child, an oreo-lover, a lawyer! Note: Thanks for all the great responses!

From Dave: q4: I agree completely...if Kraft can make Oreos and all that w/o using trans fatty acids, then there should be legislation that requires them to. There is no reason to create a cookie that is capable of withstanding a nuclear apocalypse. Other foods have expiration dates, and Kraft's foods can also. I think that there is no excuse for ruining the health of consumers for the sake of marginal profit.

From Hunni Bunches: q4: I agree, because it is not right for a big food company to use an ingredient in their product that they know is harmful to our health, just so they can make a bigger profit. They need to be restricted from producing and marketing their product until they take the harmful fat out of the product.

From Laura M: q4: I choose to comment from the perspective of an oreo-lover. It is aggrevating to find out how bad these partially hydrogenated oils are for our bodies and too find out they are in America's favorite sandwich cookie. I think Kraft should change the content of oils in their Oreo cookies and other foods for that matter. If Kraft doesn't change the ingredients in the cookies, they should have to put a warning on the package that alerts consumers to the dangers of these oils and that their product contains a significant amount of them. [Image of America's yummiest and most loved cookie!!]

From yosh: q4: I eat oreos. I love oreos!!! I think the lawsuit is about as retarded as the hot coffee lawsuit against McDonalds. I know that cookies are not the best decision for my health and that is why I limit myself. Parents can do the same for their children. I do not see anything wrong with oreos. I have ate them my whole life and I am just fine.

q 4: I feel pretty torn over this whole idea of sueing food companies. On the one hand, such lawsuits increase public awareness of the dangers of these foods and can maybe bring about change in how these things are sold. On the other hand, at some point consumers have to educate themselves. I do think a warning should be placed on all food containing trans-fat, but lets face it--people would still buy the stuff. When it comes to children though, it's even harder to decide what the best course of action is, what with their limited ability to see the outcomes of their present actions.

From cookie: q4: I take the side of a parent. I do not understand why they would sell great amounts of harmful substances this way. My children do in fact love oreos and I find it a really easy snack to give them. It is hard for me to believe we are feeding our kids something harmful without even knowing it. Had I not read the article I would never have known. I do not like the fact that we are looking out more for the longer shelf life than for the health and safety of our future generation. We buy all kinds of foods that don't last long on the shelves so why can't this be another one? If anything it would be a good idea because you would have to produce more of the product which means you would have to hire more workers. With the economy the way it is now why wouldn't we look at it this way?

From Billy Biology q4: You have to be kidding! This is not a real article, right?? …. I have lived on this earth almost 27 yrs and I have yet to see an oreo jump into a child's mouth. (At what point are the parents going to take responsibility for their childrens actions!?)

From Amber: q4: Like the article said, Oreos have been eaten for 90 years and 450 billion oreos have been eaten. I am not sure that after 90 years anyone would want to stop buying them just because someone ate oreos and now has heart disease. Oreos are my Great Grandfather favorite snack; he is 97 years old and has eaten them almost everyday.