So, here we have an example problem that says use the words in the word bank that you can see down below right here to fill in the blanks and complete the sentences that you can see down below here. And so notice that the words in the word bank are desmosomes, proteins, tight junctions, water, and barrier. And so this first sentence says that keratin is one of the most abundant and important proteins in the human body. Now, this first blank here has to be filled with one of these words in the word bank. And so, we know that keratin is not going to be a desmosome nor is it a tight junction and of course keratin is not water.

And so, we're between either proteins or barrier here for this first blank. Now, let's stick with proteins for now and we can always make a change later if we need to. So, it is the case that keratin is one of the most abundant and important proteins in the human body. And so because we've used this word in the word bank we can go ahead and cross it off the list. Now, the second sentence says that one of its primary roles is forming the skin barrier.

Now, we know that one of its primary roles is not forming desmosomes nor is it forming tight junctions nor is it forming water. And so, we know that keratin's primary role is to form the skin barrier. And so that's going to be this next blank here. And we can cross it off our list. Now, here the 3rd sentence says, the tight junctions between keratinocytes and the epidermis protect the body from water loss, pathogens, and other harmful substances.

Now, in terms of something this blank here, it's actually going to be water loss since it doesn't make sense to have desmosome loss or tight junction loss but it is going to prevent water loss. And so, water is going to be this 4th blank here. And so we can cross it off our list. And so now that we know that this is going to prevent water loss, this blank right here must either be desmosomes or tight junctions. And of course, recall that tight junctions are going to hold the cells so tightly together that it creates a leak-proof barrier preventing water loss.

And so, this blank here is going to be tight junctions. So, the tight junctions are going to help, are going to fall between keratinocytes holding the keratinocytes really closely together in the epidermis and protect the body from water loss, pathogens, and other harmful substances. And so of course, this means that the final blank here must be desmosomes. And so, desmosomes are also going to be an important connection. And these desmosomes are going to connect keratinocytes very firmly together, and hold them to each other very firmly, providing mechanical strength to the skin.

And so this here concludes this example problem, and I'll see you all in our next video.