So here we have an example problem that wants us to complete the table that's down below right here. And notice that this table is showing us the environmental levels of glucose and lactose concentrations, cellular levels of glucose, C amp and lactose concentrations. And then in this last column over here, wants us to determine if the lack opera and is being expressed or not based on the indicated conditions. And so we'll focus on one row at a time here, filling out all of the blanks that we see throughout. And so notice that the first row here has glucose environmental levels being hide and lactose environmental levels being high. So, of course, cellular levels of glucose are also going to be relatively high when environmental levels are high as well, and recall that glucose has an inverse relationship with C AMP levels. And so if glucose concentrations are high, then C AMP levels are going to be low now, of course, if lactose concentration levels on the environment, the outside environment are high, that's also going to translate to lactose levels being high, uh, within the cell as well. Cellular levels of lactose will also be high And so I recall that the lack opera is only going to be expressed when glucose is not available, because glucose is going to be the preferred energy source. And the lack operas should be off when glucose is available. And so notice that glucose levels are pretty high here. And so glucose is available for the cell. And so that means that it will be using glucose as the primary source, even though lactose is available. And so the lack opera is going to be off here. Or we can say that no, the lack opera and will not be expressed Now looking over here, we can see again that glucose concentrations are going to be high this time. Lactose levels are going to be low. And so, of course, having high environmental glucose levels is going to lead to having high cellular glucose levels. And so here we can put in high. And, of course, recall that C. Amp has an inverse relationship with glucose. And so if glucose is high, then C amp levels are going to be low. And, of course, having a low lactose, uh, environmental levels is going to translate to having low cellular lactose and again, under these conditions, the lack opera is only going to be expressed when those genes are needed to break down lactose and again. Because glucose is the preferred source, we know that the lack opera is not going to be expressed in the presence of glucose. It's also not going to be expressed in the absence of LAC tips. And so once again here we have some conditions that say the lack opera and will not be on it will be off under these conditions Now. Next, we have the third row here, which is highlighted in yellow, but we're actually going to skip this row and go to the last row here before we actually go to the yellow Rose. So let's skip that row and we'll come back to it here shortly. Let's focus on the bottom row here. And so notice here that glucose concentrations are low on the environment, and so that's going to translate to glucose cellular levels also being low. And we know that C. Amp has an inverse relationship with glucose. And so if glucose levels are low, C AMP levels are going to be high now. Of course, having low. Lactose in the environment is also going to translate to having low lactose intracellular levels or cellular levels. And so should the lack opera and be expressed, or should it not be expressed? Well, notice that glucose levels are low, so glucose is not going to be available as the primary energy source, but also notice that lactose levels are also low. And so the lack a bronze should only be turned on if lactose is available as well. And so because lactose is low here, the lack opera and should not be expressed. And so once again, we have a scenario that is no. And so now we focus on this third column here that's highlighted in yellow, and what you'll notice is that glucose environmental levels are low, but lactose environmental levels are high. Now. Having low environmental glucose levels is going to translate to having low cellular glucose levels, and C AMP once again has an inverse relationship with glucose levels. And so if glucose levels are low, C AMP levels are going to be high. And, uh, again, if lactose is high on the environment, then lactose is also going to be relatively high and the cellular levels, and so we can say hi here as well. And so under these conditions, should the lack opera and be expressed and here we can say yes. The lack opera in should be expressed under these conditions, because glucose is not available to be the primary energy source and lactose is available. And so these are the conditions that are needed to allow for, uh, lack opera and to be expressed, and also notice that the high cellular C AMP levels are going to lead to the lack opera and being expressed. And again, we're going to talk about exactly how C amp impacts the lack opera in our next lesson video. But for now, this here concludes this example problem, completing this entire table down below. And so we'll be able to get some more practice as we move forward. So I'll see you all in our next video