The Use of Radioisotopes: Study with Video Lessons, Practice Problems & Examples

Radioisotopes are unstable atoms that release radiation, crucial for cell biology. They help monitor molecules by attaching to them, allowing scientists to determine their quantity, location, and movement within cells. Techniques like gel electrophoresis can visualize these molecules, revealing different bands that indicate size or type. This method is essential for studying proteins, DNA, and other biological materials, enhancing our understanding of cellular processes and interactions.

Radioisotopes

Hi. In this video, I'm going to be talking about radioisotopes. So you may be asking the question, why are we talking about radioisotopes in a cell biology class? But it's because radioisotopes are used by cell biologists to monitor molecules in a variety of different ways. So first, let's refresh what radioactive isotopes are. They are atoms where the nucleus is unstable. That means they can release radiation. There are 3 types of radiation that can be released: alpha, beta, or gamma particles, and they each result in a loss of slightly different things, such as protons, neutrons, electrons, or photons. And this is much more for chemistry, I'm just putting it here so you kind of get the idea in case you run across it in your textbook. But, you know, this is much more chemistry-based than cell biology. However, cell biologists can use different types of techniques to detect isotopes and biological materials. Things like cells, some types of gels that biologists run, or filters that they use to examine proteins, molecules, DNA, or whatever they use. And so, they're super important in cell biology because these radioactive isotopes can be attached to specific molecules. You can do that yourself in a laboratory, or you can actually purchase them from companies that sell materials to laboratories. There are pretty much most small molecules and a lot of proteins you can just buy with this radioactive isotope on it. Scientists use this to determine the quantity of molecules in a cell, determine the location of molecules in a cell, and even follow the movement in real time of a molecule in the cell. You can do it over time or in response to a chemical. So you can see that there's a variety of different uses for these radioisotopes. An example of this is if we have this molecule, it kind of looks like DNA, but you can imagine it being anything. And it has this isotope on it here, these like red stars. And then you can run that on a variety of different materials that scientists use. This one's called a gel, and there are videos on that in case you're wondering what that is. You can see that there are obviously these different bands. Each of them is going to represent something different, either a different size or a different DNA or protein, or molecule. And depending on what the experimental setup is, that could tell you a lot about the quantity of that molecule, the location of that molecule, how that molecule responds to different changes in the cell. So radioactive isotopes or radioisotopes are an extremely important cell biological tool. So with that, let's now move on.

Which of the following types of radiation results in the loss of an electron?

• A. Emission of alpha particles
• B. Emission of beta particles
• C. Emission of gamma particles

Which of the following characteristics can a radioisotope NOT determine?

• A. The quantity of molecules in a cell
• B. The location of molecules in the cell
• C. The size of a single molecule in the cell
• D. The movement of a molecule in the cell

Here’s what students ask on this topic:

What are radioisotopes and how are they used in cell biology?

Radioisotopes are unstable atoms that release radiation due to an unstable nucleus. In cell biology, they are used to monitor molecules by attaching to them. This allows scientists to determine the quantity, location, and movement of these molecules within cells. Techniques like gel electrophoresis can visualize these molecules, revealing different bands that indicate size or type. This method is essential for studying proteins, DNA, and other biological materials, enhancing our understanding of cellular processes and interactions.

How do radioisotopes help in determining the quantity of molecules in a cell?

Radioisotopes help determine the quantity of molecules in a cell by attaching to specific molecules. When these radioactively labeled molecules are run through techniques like gel electrophoresis, the resulting bands can be visualized and quantified. The intensity of these bands correlates with the amount of the molecule present. This allows scientists to measure the concentration of various molecules, such as proteins or DNA, within the cell, providing valuable insights into cellular functions and processes.

What types of radiation can radioisotopes release and what do they signify?

Radioisotopes can release three types of radiation: alpha, beta, and gamma particles. Alpha particles consist of two protons and two neutrons, beta particles are high-energy, high-speed electrons or positrons, and gamma rays are high-energy photons. Each type of radiation signifies a different form of decay and energy release. While this is more relevant to chemistry, understanding these types helps in comprehending how radioisotopes can be detected and used in biological experiments.

How can scientists visualize molecules labeled with radioisotopes?

Scientists can visualize molecules labeled with radioisotopes using techniques like gel electrophoresis. In this method, the radioactively labeled molecules are run through a gel, which separates them based on size or type. The gel is then exposed to a detector that can sense the radiation emitted by the isotopes, producing an image with bands. Each band represents a different molecule or fragment, allowing scientists to analyze the quantity, location, and interactions of the labeled molecules.

What are some practical applications of radioisotopes in cell biology research?

Practical applications of radioisotopes in cell biology research include tracking the movement of molecules within cells, determining the quantity of specific molecules, and identifying their locations. For example, radioisotopes can be used to study protein synthesis, DNA replication, and metabolic pathways. By attaching radioisotopes to molecules of interest, researchers can monitor these processes in real-time, providing insights into cellular functions, interactions, and responses to various stimuli.