3.02 The Cell: Living Machines

Did you know that Rudolph Diesel actually invented the engine with the intention of it running on vegetable oils? If you are interested take a few minutes for a quick Pod trip and listen to this Podcast about Biodiesel fuel:

Technology Make It On Your Time: Biodiesel (27 min. - listen just to the first several minutes and learn what this fuel is and how it is made.)

Yep, it's true. The same olive oil in our Greek salad's dressing can power us and our diesel engine. However, unlike the van's diesel engine, humans can't run on olive oil alone; we need a wide variety of elements, in the form of nutrients, and water, in order for our cells to function and do their work properly.

Carbon   ---   Hydrogen   ---   Oxygen   ---   Nitrogen

These four elements make up the majority of the important molecules in living things. Our van's bio-diesel engine uses heat and pressure to get the olive oil to release its energy, which is a pretty simple process. On the other hand, your body has so many chemical reactions going on right now, we could not even count them. All of these chemical reactions are going on inside the cells that make up your body.

The macromolecules we mentioned earlier

• carbohydrates (sugars and starches)
• lipids (fats)
• proteins
• nucleic acids

are required by living things to maintain an internal balance, or homeostasis, as these reactions take place over the course of each minute throughout the day . They each can provide energy, but they have other functions as well.

The pictures below are interactive. Explore them, by clicking on each term, to learn more about each molecule.

Text-only version

Now that was a feast fit for a king. A whole lot better than hot dogs! I bet I ate from every point on the food pyramid and some points twice. Pull down the van's video screen and watch these clips on Carbohydrates, Lipids, Proteins, and Nucleic Acids. They should help you put all this stuff about molecules and energy together.

Text Version

Carbohydrates (02:10)

Text Version

Lipids: Fats and Oils (00:37)

Text Version

Proteins (01:47)

Text Version

Nucleic Acids (00:59)

In the end, cells are microscopic machines that process carbohydrates, lipids, and proteins to maintain an internal balance and continue life. Let's check out the inside of a cell and see how it works.

Hold on to your hats because the next part of this tour will be amazing! We're going to be some of the first people to visit the newly reopened tomb of the Pharaohs.

Move on to the Travel Log tab to complete the activity.