Chemistry: What Are Fossil Fuels?

This week in Chemistry, we are taking a little trip away from your text book and are going to study something out of ~Chapter X~.....

What's Chapter X, you ask? It's a chapter that I built myself so that you can learn a little more about hydrocarbons - how we get them, how we use them, and how they affect us. By the end of the chapter, you will know more about alternatives to using hydrocarbons also.

To start off, go to this link: What are fossil fuels?

Use the website that comes up to answer the questions on your class handout.

Chemistry, Energy and You

In Chemistry this week, we're talking about energy, and when we talk about energy, a lot of times, we're talking about heat (energy flowing from one place to another). You are also learning that the energy needed to raise the temperature of a substance, like water, is called a calorie.

Wait a minute. I thought calories had to do with food?

Well, calories are related to food. You just use the word "calorie" a little differently. When the "calorie" is associated with caloric intake, you are actually referring to the heat (energy) released from the chemical reactions that take place in your body when you eat food and then break the bonds between all of those little molecules in your food. So if a particular food has a lot of "calories", that means that more heat can be released by breaking its bonds than other foods. The amount of energy that can be released is not to be confused with whether or not the food is good for you. A candy bar may have a lot of calories, but it has few nutrients that you actually need and has lots of stuff in it that you don't need. It also gives you the kind of energy that gets used up really quickly, but leaves you with oils and fatty materials that hang around in your body a long time.

All of the activities you do during a 24 hour period require different amounts of energy. Running, for example, requires a lot more energy than jus sleeping (which does require energy, by the way.) So because different people have different energy requirements, that means that a healthy diet varies depending on who you are.

In class, I want you to go to the USDA's food pyramid website and find MyPyramid Tracker (on the right side menu). We're going to do three things: 1) Calculate your caloric intake. 2) Calculate your Energy Requirements. 3) Compare the two.

To do this, scroll down to "Check it Out" and click there. You can register as a user for free later if you want to use the tools you're about to see on a regular basis.

Now fill in your information about how tall you are, etc. This will help the tracker identify how many calories you use for any given activity.

Click on "Proceed to Food Intake." Here, you can type in foods that you eat on a normal day. To find your food on the list, type it in, hit "Search" and select what you want from the list that appears. Click "add" for each food.

When you are happy with your list of foods for one day, click on "Select Quantity." Now you can tell the Tracker if you would normally eat an entire pizza or just one slice (big calorie difference!). When you are finished with that, click "Save and Analyze."

Now you have two options. Choose the first on - "Calculate DG Comparison," which will compare your intake to what is healthy. Take a look around.

Now scroll back to the top of that page and find the little sphere labeled as "Physical Activity Entry." Choose the "Standard Option" when asked. Now you are going to make a list of what activities you perform on a daily basis. To choose from a complete list of activities instead of thinking them up on your own, you can click on the "Select" button and choose from the detailed list that shows up. Add each activity you want and when you are finished, "Select Duration."

Now is the hard part - make those activities fit in a 24 hour period. When you are finished and everything adds up to 1,140 minutes' worth of activities, tell the Tracker to analyze your activities. Choose the to calculate your physical activity score. This is your energy requirement for one day.

Now go back to the spheres at the top of the page again and choose the one that says "Energy Balance." This will compare the amount of calories you need to what you actually take in on a typical day.

How do your numbers compare? People who take in fewer calories than they need will lose weight as they bodies get the energy they need from anywhere they can get it - usually fat reserves in the body. People who are taking in more calories than they need tend to gain weight because their bodies make the executive decision that just in case a famine occurs in the near future, all of that energy ought to be saved. The energy gets saved as fat, which is not that big of a deal if you live somewhere were famines occur. The problem is that in the U.S., famines don't occur too terribly often. Food is pretty readily available for most folks here and a lot of that food has a high caloric content. A great deal of U.S. citizens live pretty inactive lives (not like you guys, who have practice before school, go to school, go to athletics, go to practice after school, then go home and work some more), eat out all the time, and eat a lot every time they eat. Not good.

Put this data in your science journals on the same page as your estimated caloric requirements that you calculated in class.

As I mentioned earlier, this tool is available to anyone, is free and if you register (also free) you can use this tool to track your intake and needs on a daily basis. You can also find information about what a healthy diet should look like for you based on your energy requirements. Pretty cool, huh?

Fall in Love with Science

Valentine's Day is just right around the corner, and whether that makes you feel warm and fuzzy inside or feel like swearing off of all major holidays, you can't help but notice that love has some strange affects on people. Loss of appetite, a racing heart, blushing, sweaty palms, lack of sleep, giddiness, bursts of energy, and the complete inability to think about anything else except the object of your affection are all the typical symptoms of falling hard for someone. Did you know that these symptoms aren't just cliche ways of describing someone in love, but are actually real reactions to chemicals in your body that are released in response to finding a possible mate?


From biology class, you know that the survival of a species depends on successful pairing between individuals of that species. And your body ensures that you're interested in the survival of your species by pumping out hormones that make you feel good about carrying the species on. Don't believe me?


That intense interest in that significant other person initially comes from the hormones estrogen and testosterone (both hormones are released in both sexes). Then when the giddiness at the very sight of that person, flushed skin and sweaty hands - that's hormones like dopamine and norepinephrine at work. Do those names sound familiar? If they do, it's because we talked about both of them during Drug Free week this past Fall. Dopamine is the hormone that your body sends out every time you do something that needs to be encouraged, like eating, getting exercise, and promoting survival of the species in general. It's also the hormone that switches pathways in the brain when addictive drugs enter a person's body.


When both dopamine and norepinephrine (the hormone that makes your heart race) work together, then you get all of those other lovely side effects, such as sleeplessness and that loss of appetite that your friends make fun of you for. The two hormones' combined efforts, along with altered levels of serotonin, also lead you to focus on that person above all other things around you. These hormones even affect the pathways in your brain that you use when you judge what kind of a person someone is. If those pathways get suppressed, you have a hard time seeing that person's faults (anyone ever heard that "love is blind?")





By the way, eating chocolate actually stimulates a similar hormonal response in your brain, which might explain the Valentine's Day tradition of buying, giving and eating chocolate.


For folks who are going the distance in their relationship, some of these intense and exhausting symptoms we've just discussed might feel like they're fading. Science backs that up too. People who are in long term relationships have shown higher levels of hormones like oxytocin and vasopressin. These two hormones are associated with building bonds between people, and are also known for interfering with hormones like dopamine and norepinephrine, so now all of that skipping of meals, being oblivious to a person's faults, and sweaty palms fade away. But don't worry - even though the rush that comes with crushing on someone might fade, a hormones called endorphins pick up where dopamine lets off. Endorphins are feel-good hormones too, and they also make a person feel peaceful, happy and secure.


Like it or not, Valentine's Day is quickly approaching, but now you know the science behind the celebration. Whether you've got a valentine or not, if you think about it, your body is pretty smart when it comes to making sure your species lives to see another generation. Pretty cool, huh?

(By the way, the information and diagram in this post came from an article at How Stuff Works, by Lee Ann Obringer. )

Math Shmath

Did you ever get the feeling that Chemistry feels an awful lot like Math class?

Even though you might feel a little lost in the midst of all of those complicated stoichiometry problems sometimes (check out the cartoon above by Sidney Harris), the cool part is science concepts are built on more branches of study, all tied together, than almost any other subject matter. Think about it - the ideas we discuss in chemistry are also often tied to:

• biology, agriculture, and earth science (chemistry explains why we see the things we see in around us),


• physics (think particle motion, kinetic energy, pressure, temperature - sound familiar?),


• history (remember that science builds on itself),


• english (anyone who ever wrote a lab report knows that you those research projects in english really do have a purpose),


• technology (technology provides the tools we use in science and, and science, in turn, helps us create better technology),


• health (chemistry is involved in medicines and their reactions in your body, for example),


• and yes, you guessed it, math.

What all of this means is that it's not hard to find some part of science that you like, even if science itself is not your favorite subject. And what that means, is that when you start thinking about careers and fields of study outside of high school, organizations that are closely related to science, (like NASA, museums, chemical companies, etc.) depend on a really wide range of people with wide ranges of interests and skills to meet the goals they have for their organization. It also means that almost any job you choose is going to involve science, one way or another.

So next time you are in science class and you start to think about saying that "you're never going to use this" - think again. Science is everywhere, my friends, and there's no escaping it! :)

"When we try to pick out anything by itself, we find it is tied to everything else in the universe. "
-John Muir (1838-1914) U. S. naturalist, explorer.