George Palade's research group used the pulse–chase assay to elucidate the secretory pathway in pancreatic cells. If they had instead performed this assay on muscle cells, where would you expect the labeled proteins to end up during the chase? (Muscle cells consist primarily of actin and myosin filaments and have high energy demands for muscle contraction.)

Video transcript

Hi everyone. Let's look at our next problem. The principal protein component of thick maya filaments is blank and the principal protein component of thin maya filaments is blank. Well we've got these two types of maya filaments. And we recall from our content videos that thick maya filaments are made up of around 300 spiral E. Arranged my assassin oops molecules Around 300 of them. The spiral and the thin maya filaments fine here are composed of acting molecules. It's a polymer of globular acting molecules and the niacin and the act and interact together to cause muscle contraction. Uh One little trick to remembering these two and keeping them straight. Um Is that when we think of thick and thin, think thin and acting with that we have sort of resemblance. They're thin and acting so that can help you remember which is which. So let's go through. Andrew choices and find the correct one. We've got choice A. With acting as the thick mile filament and myosin is a thin so that's reversed. So choice A is not our correct answer. Choice B. Has miocene as the component of thick filaments and acting as a component of thin. So there's our correct answer. Choice B. Choice C. List. Troppo mate chosen as the first one with my son is a second while choice delis acting and troponin. Well just to be thorough here, Troppo myosin and troponin are also involved in muscle contraction and interact with these two types of filaments. Um but trump myosin, troponin. Um The troponin actually causes the trouble miocene blocks the binding site where miocene binds to act in it cause muscle muscle contraction. And when calcium binds to the troponin molecules attached this triple miocene, it moves the travel magazine out of the way, exposing that binding site on this thin acting filament, which allows myosin to bind to it and cause muscle contraction. So triple myosin troponin involved in muscle contraction, interact with these micro filaments, but not a component of thick or thin micro filaments, so both C. And D. Are incorrect. So again, principal protein component of thick metal filaments is Choice B. Myosin and the principal protein component of thin metal filaments is acting. See you in the next video.