In this health video you will learn the energy source of cells.
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Raena Morgan: Hi, I'm Raena Morgan with iHealthTube, talking with Dr. Rapaport today. Dr. Rapaport, could you talk to us about ATP? Dr. Eli Rapaport: I started getting interested in the role of ATP or intracellular inside the cell signals that affect cell proliferation in cancer. The common thought at that time was that extracellular signals had to be stable compounds, such as polypeptide hormones, such as insulin, for instance, or steroid hormones like cortisol. Intracellular signals, such as ATP have to be labile or metabolically labile. In other words, they are not stable, they degrade and reform, degrade and reform. Raena Morgan: Isn't ATP about energy, the energy in the molecules. Dr. Eli Rapaport: Exactly, exactly, exactly. Now, ATP is the energy currency of the cell. It's the major energy source of the cell. Raena Morgan: Would you repeat that because that seems vitally important. Dr. Eli Rapaport: Yes. Well, it is energy and energy equates with ATP, biological energy equates with ATP and we'll show later how ATP's produced inside the cells. Raena Morgan: So it was Dr. Eli Rapaport: But inside the cell, ATP is the major energy source. Raena Morgan: That's what ATP is; it's the major energy source in the cell. Dr. Eli Rapaport: Right. In addition, ATP is capable of utilizing its energy to form chemical bonds, to activate a whole variety of chemical agents, so they are capable of carrying on further reactions and to allosterically effect the reaction of other proteins. When you say allosterically and we'll go through this theme ATP interacts, or binds to molecules to other proteins, and thereby affects the activity of these other molecules. Raena Morgan: And that's what we need to know the general public, we need to know about how the energy works in our system and this is what ATP is. Dr. Eli Rapaport: Right. Now, the big advances in ATP came in about 1980s. At that time, people began to discover that ATP has a major, major activity outside the cell extracellularly by interacting with specific receptors. Just to give you an idea, there are now eight receptors that have been identified for the 2 it's called 2X receptor for ATP and seven 2Y receptors, they differ in their mechanism. So there are at least 15 receptors for ATP. Now, it gets a little bit more complex. ATP is comprised of 3 specific chemical modalities. One is the adenine base, the other one is the sugar, the ribose. Together, the adenine base and the sugar are called adenosine, which is also a major player both intracellularly and extracellularly. Now the third component are the three phosphates. The energy in ATP is in the chemical bond between the second and third phosphate the beta to gamma bond. This, as I said, this energy can be converted to the formation of other chemical bonds or converted to mechanical energy, such as in muscle action. Raena Morgan: Okay, Dr. Rapaport. We'll come back and we'll visit more about this complex, but very exciting subject. Thank you very much. I'm Raena Morgan with iHealthTube.