 So the amazing melanocyte goes through the process of melanogenesis to make melanin. But that's not the end of the story. The production of melanin doesn't really do anything because the melanocyte actually packages the melanin. So it goes through melanogenesis, produces, goes through that whole cellular mechanism, produces melanin, and then if you take a look at this image that I have, you can see that we have all the keratinocytes. We have the melanocyte. It's that octopus looking cell at the bottom of this image. And if you look super close, you can see little dots in here, and those those are dots of melanin. Those are dots of the pigment. The melanocyte produces the pigment and then packages the pigment into little vesicles full of melanin, and those guys are called melanosomes. I'm gonna go ahead and just label like, look, here's one right here. This is a melanosome. Melanosome, like isosome. It's just a vesicle but filled with melanin. Tell me. Great opportunity to review. How do you think who is responsible for packaging the melanin into these melanosomes? Who would you say like, okay, you do that job? My first thought is the Golgi apparatus, right? That pancake structure, that pancake organelle, that was connected to the rough endoplasmic reticulum. So I also would think, oh, I bet the rough endoplasmic reticulum might have a role in packaging melanin. I'm not positive about that because I don't think the ribosome has a role in melanogenesis that process. That's facilitated not by a ribosome, but facilitated by the enzyme tyrosinase, right? Are you with me? But I bet the Golgi body plays a role in packaging up the melanin and making a little bubble. And then if you had a bubble of melanin and you wanted that to get to the outside, what kind of process might you go through? How about what kind of transport might you go through to get one of these melanosomes from to make a melanosome for the keratinocytes to grab? I'm going exocytosis home, kids, and I know exocytosis dumps product out, but there are also strategies where the whole vesicle could be ending out. They actually are not positive how the melanosome ends up in the extracellular fluid and no longer in the melanocyte. But these melanosomes, then, not only do they get produced by the melanocyte, they get engulfed by the keratinocyte. You tell me. What strategy are you going to use if you are a keratinocyte, and you're like, dude, like this guy right here. I want a little bit of that melanosome inside me. I want to decorate with some melanosomes. How are you going to get a vesicle of melanin into your insides? That would be endocytosis. Do you agree with that? Endocytosis. Just endocytose that melanosome, and now you have this bubble of melanin inside your cytoplasm. I'm just going to label this keratin site just for a perspective. So you remember that this is what we're talking about. And these keratinocytes basically yumpsulize these bubbles of melanin. And that melanin, then, as they the keratinocytes continue on their conveyor belt of death to the surface where they are dead, they contain the melanin pigment. So we now know that inside our keratinocytes is melanin that was produced by the melanocyte, and we have some sense of how this process might take place. In the next section, we're going to talk about why do- oh because I want to tell you this. I'm telling you this and I'm writing it down loud and proud. I'm going to tell you this fact that is going to be a puzzle in your brain. All humans have the same number of melanocytes ha ha. I love telling you things that are surprising. That is not what I would expect. Because why? Is that what you would expect? I can visualize melanosomes doing their thing, but I would assume that to make more melanosomes, we would need more melanocytes. Nope. Everybody has the same number. All of us have the same number of melanocytes. There is variation in skin color though, isn't there? So let's talk about how that comes about what changes? What is different about our melanocytes that results in different colors of skin?