In this video, we're going to begin our introduction to energy. And so energy is defined as the ability to perform work. And this term work can take on a lot of different meanings, but it's not referring to your homework in this sense. In biology specifically, work is referring to the transfer of energy that causes an overall change. And so, really, energy can be defined as the ability to perform an overall change in a living system. Now in our course, we're going to talk about 2 different types of energy, potential energy and kinetic energy. Now, potential energy is defined as energy that has potential. It is stored energy, and the stored energy is available to do work or to cause an overall change. Now, the second type of energy that you all should know is kinetic energy, and kinetic energy is the energy of motion. So any substance that is moving or is in motion is going to have kinetic energy.
And so let's take a look at our image down below to distinguish between these two types of energy. And so notice on the left-hand side over here, we have this little chart where we have the energy types in the left-hand column including potential energy, the storage form of energy, and kinetic energy, the energy of motion. And then we have examples of each of these types of energy. And so let's start off with the potential energy here. There are different types of potential energy. There are different ways to store energy. So one example of potential energy that is stored is gravitational potential energy. And so gravitational potential energy is going to be when something is going to have a lot of it; it's going to be quite high with respect to something that has gravity. And so for example, a biker that is on the top of a hill, like this biker here which is on the top of a hill, this image of the biker that you see here on the left is really just a screenshot of this image of the biker over here on the right. So a biker that's at the top of a hill is not moving, but it still has high gravitational potential energy. Now, another type of potential energy, of stored energy, is chemical potential energy. And chemical potential energy is when energy is stored in chemical bonds. And a classic example of a molecule that has chemical potential energy is glucose, which is the most abundant and the most common sugar that exists.
Now in terms of kinetic energy, the energy of motion, really all moving objects are going to have kinetic energy, including a biker that is actually coasting or moving really, really fast is going to have kinetic energy. But also, muscle contractions are a form of kinetic energy. So when you flex your bicep or get up to go get a glass of water, those muscle contractions are considered a type of kinetic energy. Now, let's take a look at this image over here on the right-hand side, which is also helping to distinguish between potential and kinetic energy. And so once again, a biker that's at the top of a hill, even though they're not moving whatsoever at the top of the hill, is going to have quite high gravitational potential energy. But as soon as this biker makes a dip in this direction, it's going to start coasting down the hill, moving really, really fast down the hill because gravity is acting on the biker. And so the biker, when it is moving, it is going to have kinetic energy. And so the potential energy is going to be converted into kinetic energy as soon as the biker starts to move. And then when the biker makes it to the bottom of the hill, the biker is going to have low gravitational potential energy because it is no longer at the top of the hill. And so this here concludes our introduction to the 2 main types of energy that we're going to talk about moving forward, potential energy and kinetic energy. And so we'll be able to get some practice in our next couple of videos. So I'll see you guys there.