Intro to Biochemistry

What is Biochemistry?

You’ve learned about chemistry. You’ve learned a little bit about biology. Welcome to the glorious interface between the two, where all those molecules, chemical properties, and chemical reactions come together in their greatest starring role: life.

The study of life on a molecular level is biochemistry or molecular biology. They’re actually slightly different fields when you get into the nitty gritty of picking a career, but, for our purposes, the main point is that we’re studying the molecules of life. And that’s a pretty cool idea! When you consider that chemical reactions power cells, which power tissues, which power organs…it’s amazing. What we’ll learn about here is pretty awesome, but it barely scratches the surface. Biochemistry is all about how and why life works, which is at once beautifully simple and mind-bogglingly complex. People make careers of biochemistry because we, as human beings, are very fascinated by, well, human beings.

Check out this video for some motivation:

Biochemistry is especially important to understand in medicine and medical research. Medicine is just a bunch of molecules that we put into our body with the expectation that they will change something. In order to know and predict the effects that this medicine will have, we have to understand the chemical reactions that normally occur in our bodies, how these reactions go wrong when we get sick, and how some molecule that we put into our bodies will fix or change that. Like I said...it’s amazing!

There are many different types of biomedical research going on. One type involves small molecules that are designed to change or fix how proteins behave. We’ll learn more about proteins later on, but they’re basically the molecules that do most of the important things in our bodies:

Another type of biomedical research that doesn’t involve small molecules involves changing or fixing our DNA to correct disease at its origin. One way to do this is through a really cool, relatively new technology called CRISPR/Cas9. You don’t need to understand any of the details of this, but it’s cool to see what new research is going on:

A third type of biomedical research involves engineering antibodies, a protein naturally produced by our immune systems to fight disease, for various medical uses. One involves fighting cancer. Again, you don’t need to understand the details, but it’s amazing to see all of the useful applications of biochemistry:

Biochemistry isn’t just important in medicine, though. It also has huge implications in agriculture, bioenergy, climate research, and even data storage:

It’ll be amazing to see what the future of biotechnology holds! You may even be an important part of creating it.

What Do the Molecules of Life Do?

In this lesson, we’re going to focus on the basics of biochemistry by answering, in pretty general terms, two very important questions: First, what are the key types of molecules in our bodies; and, second, why are they important? By understanding these basics, you’ll be able to start to learn about and understand more advanced processes, such as the ones happening on the cutting edge of biotechnology as shown in the videos above.

There are many different types of molecules in our bodies in all shapes and sizes, from just one atom in size to thousands, and each of those molecules has a purpose. Obviously, we can’t talk about every single molecule in the body here, so we’re going to break them down by category, first by size. We’ll start with a few of the important micromolecules, which literally means “small molecules,” found in living things, and then we’ll our way through the main categories of macromolecules, or “big molecules.”

All these molecules come together to make a sort of cellular factory, where every molecule has an important job to do. We’ll learn more about some of these important jobs as we talk about each molecule, and then we’ll see some examples of these jobs at work when we learn more specifically later in the unit about some of the things our cells actually do. For now, it might be helpful to see a sort of overview of the types of roles these molecules play:

In complex organisms, those cell “factories” turn out to play just one tiny but extremely important role in the overall functioning of the body, which can be compared to an advanced, highly functional society where everyone is doing the job they’re perfect for, communication between these jobs is a breeze, and, together, the cells can do some pretty remarkable things—like make you you. One molecule may seem like nothing in comparison to that grand scheme of things, but without all those molecules doing exactly what they’re good at, not even the simplest forms of life could exist. Tiny molecules are kind of a big deal!

Summary

You should understand:

That complex life has many levels of organization, the smallest being molecules. All of the interesting and complicated things that life does can be traced back to a molecule doing something.
That biochemistry has important applications in medicine, among many other fields.

Learning Activity

Have you ever been curious about how something in your body works? Or heard someone talking about some concept in medicine that you didn’t quite understand? Well, the good news is, the more tools you have in your science arsenal—the better you understand the basic principles—the better you can understand more advanced ideas. And you’re starting to get pretty good at science, now! But, even scientists don’t know everything about every field of science, and are constantly learning new things. So, here’s your chance to learn something new about something that interests you!

Fortunately, especially at your level of learning, there are a ton of amazing resources already out in the world to help you understand new ideas. That way, you don’t have to go digging through all of the really advanced, science-y primary literature by yourself (although that can be really fun too, if you know what you’re doing). For example, there are a lot of great YouTube videos that have been put together that explain relatively advanced concepts on a simple level, such as these TedED videos.

For this learning activity, choose one of these videos—or pick another topic related to biochemistry—that interests you. Then, watch the video and see if it starts to make sense. If not, try looking for a couple more videos or articles on the same topic! If you search the web, keep in mind that some websites are better than others. Those that end in .edu, .org, or .gov are usually the most reliable sources of information. Then, answer the questions below,

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