VEGANGELICA

Hi kayleigh,

Toretorden gave a good description of how we are, each of us, a community of cells that grow as they do by following the instructions that are their DNA molecules, with the environment having some impact on how the instructions are used.

My interest in life and how it works inspired me to study biology. You get a feeling for "how humans (living organisms) actually work" by studying general biology, anatomy, cell biology, and biochemistry, and then chemistry and physics. Usually students start with biology, then take physics, then chemistry, but may not get to really feel or see how the information combines to give a deeper understanding of how life works until they get to biochemistry (and enzymology). I feel biochemistry, the chemistry of life, really shows best on a fundamental level how our bodies use food energy to keep themselves and their processes going.

I get really excited about the topic of how we work! For example, do you recall that inside your cells are small oval structures, the mitochondria, which allow your cells to transfer some of the energy of food into the energy of a type of molecule (ATP) that cells use to drive cell processes? This process requires oxygen, and is essentially like a controlled fire. When you mix wood, oxygen, and a spark, you get fire. In us, the food that we eat is what gets "burned," but the body doesn't release all the energy as heat. Instead, a lot of the energy is bound up as chemical energy...the energy that is in the bonds holding one atom to another.

Also, something else fascinating is that our cells have mitochondria because long ago one of our (free-living) ancestor cells engulfed (but did not digest) a free-living bacterium, according to the theory of endosymbiosis (which is accepted as fact because of all the evidence).

So, we humans (and other animals) are like a slow, controlled burning fire...and we are partly bacterial in origin! Weird and wonderful.

I love the way we living beings are like one gigantic organism that stretches through time, like a growing vine, where only the tips of the branches remain alive. Each of us feels like a separate being, but in fact is actually just the present-time manifestation of this giant organism (life) that began billions of years ago.

I don't worry about what will happen to the universe far in the future...but I definitely think about it. Learning about what science predicts gives me a sense of perspective...and a sense of sadness for those organisms who will probably evolve on other planets far in the future and, due to the universe's expansion, will not be able to see and learn as much about the universe and its origins as humans can now.

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