Bioquímica: ATP, FADH y NADH. Nivel experto para principiantes EN 7 MINUTOS

What’s up friends? How are you? Today we will see another topic of biochemistry.

In the past video we saw a light introduction to biochemistry, and now we already know that food (substrate) is cut, I mean, hydrolyzed, by enzymes. Such food is being cut so that on each step they result shorter and shorter, and by making substrate from large to short, it will produce energy. But how is that such energy is stored?

Where is it stored? To where is it taken so that our body can already use it? Well, today we will see all that.

Well, as I was telling you, here is the food or substrate, so an enzyme arrives and cut it, hydrolyze it, and when cut, food is now in 2 shorter pieces, and this cut produces energy, it gives energy to the cell. This is the cell, so here is the substrate (food), here it is cut in 2 and produces energy, this cut produces energy. The problem is that cell cannot use this energy yet, because that energy can only be used in the mitochondria.

How will energy manage to arrive to the mitochondria (where it does can be used)? Well, it will use 3 types of different transports. They are called “energetic molecules”, and those energetic molecules can be ATP, FADH and NADH.

This energy produced is catched by one of this 3 energetic molecules, and once they have been catched, they bring them to the mitochondria and leave them there, and this is how cells can use energy and can be alive. Their names are: ATP (adenosine triphosphate), FADH (flavin adenine dinucleotide), and NADH (Nicotinamide adenine dinucleotide). The truth is that I do not know the complete names, I just know ATP, FADH and NADH, but it does not matter that you do not know the complete names.

What matters is that you do know their function. These are the energetic molecules that will catch the energy, the electrons (because the electrons are energy that is produced), they will catch them and will bring them to the mitochondria so that they can be utilized. These 3 molecules are around the cell swimming and waiting until energy is produced in order to go there and to catch it and bring it directly to the mitochondria.

So, when they are swimming looking for energy, they still do not have energy because they have not yet catched it, so they are like inactive, and when they catch the energy, they are now like active. So, this is how molecules are read when they are inactive and this is how molecules are read when they are active, I mean, when they catched the energy. When ATP is inactive, one phosphorus is taken away and now it is ‘di’ of 2, adenosine diphosphate, of 2 phosphates, inactive.

And, when it is active, a phosphorus is added and now it becomes adenosine triphosphate. In the second molecule (FAD), when FAD is inactive it does not have 2 hydrogen atoms, and when is active, it does have them. The same in the case of NAD, when it is inactive, it does not have hydrogen atoms and, when it is active, it already have them.

Also, instead of saying ‘on’ or ‘off’, you can say ‘active’ (on) or ‘inactive’ (off), but it is just the same, the point is to understand the idea. So let’s imagine that the molecule is swimming and suddenly it finds the energy (any of the 3 molecules), catches it and by catching the energy, remember that it turns active. Well, when active, passing from inactive to active, is called reduction.

Reduction means gaining of electrons. So, when these molecules catch electrons, they are reduced. Then, they bring them until the mitochondria and there they leave them, they leave those electrons.

And now, the opposite process, I mean, from active to inactive is called ‘oxidation’, when those molecules lose electrons. The same cycle with this energetic molecules occurs too many times. But, why the cell decided to use those 3 molecules to store / pack the energy and bring it to the mitochondria?

Why using these 3 molecules and no other ones of the thousand molecules that exist in the cell? This is a very interesting question. This 3 molecules have something in common, and it is that they have a cyclic structure.

I mean, it is a circle. So, for instance, when an electron arrives to the molecule (this is the symbol of electron), when an electron arrives to the molecule, it enters into it and the nature of the electron is to advance, to move. So, once it is inside, the electron will be looking for an exit and will start jumping to the other electron right here, but it will not be able to exit as it is closed, it is cyclic, so it will jump to the next one, it will neither be able to exit and jump, jump, jump and have an entire lap and the electron just could not exit, it was trapped because the molecule is cyclic.

This jumps given by the electron are called “resonance effect”. This is why the cell, very smartly, uses this 3 molecules to be able to bring its energy to the mitochondria because the electron cannot escape in this way, so it will be able to bring the electron to the mitochondria and release them there. Each one of these 3 molecules catches different amount of energy.

FAD catches 2 times more energy than ATP, and NAD catches 3 times more energy than ATP. So, if we see it this way, 1 FAD equals to 2 ATP molecules, I mean, it catches 2 times the energy than 1 ATP molecule, and NAD catches 3 times more, it equals to 3 ATP molecules. All this is very important because it will help us to analyze metabolic pathways, I mean, how the food that enters our cells are being cut / hydrolyzed, and we will be seeing on which steps of the metabolic pathways is produced ATP, FAD and NAD.

This is going to help us because by making the count of how many ATP, NAD and FAD were produced, we can calculate how much calories is burning our body, because remember that calories equals to energy, and this molecules catch energy. So, when using the energy of this molecules, we are using calories. Well my friends, this is it.

I will keep making more videos of biochemistry so that we have in the channel a complete section of biochemistry videos containing all or almost all metabolic pathways, aiming to understand well all the insight of biochemistry, how do enzymes work, I mean, how do they cut the food / substrate, to which speed do they make it (this is Km and Vmax), we will be learning all that. If you liked this video, you already know to subscribe please. If you have doubts please leave them below and I will try to answer them.

And as you know, do not stop watching more videos!