most UK carotic cells contain an organel known as the mitochondria now the number of mitochondria found in any given cell depends on the type of cell we are talking about some cells contain thousands of mitochondria while some cells contain only one now mitochondria are basically membrane enclosed organel that are responsible for forming the majority of the energy that is used by the cell and we form the energy the cells form the energy in the form of chemical molecules known as ATP or Denine triphosphate now because of this because the mitochondria produces the majority of the energy that the cell uses we commonly refer to the mitochondria as the nuclear power plant of our cell because it produces the energy that basically Powers the different types of processes that take place within our eukaryotic cells as well as within that eukaryotic multicellular organism now there's a theory known as the symbiotic theory that basically States or describes the way that we obtained the way that eukariotic cells obtained that mitochondria so it's believed that eukariotic cells essentially engulf some type of procaryotic cell such as a bacterial cell and then eventually that bacterial cell developed into our mitochondria and this theory is known as the symbiotic Theory so basically there is a symbiotic relationship between the eukariotic cell and our procaryotic system that eventually became our mitochondria now what exactly are some other functions of our mitochondria so other notable functions of the mitochondria organ now include programmed cell death known as eposis calcium signaling as well as cellular differentiation so what exactly is eposis so eposis is basically the ability of the mitochondria to release some type of molecule that essentially kills off our cell and this is similar to the way that nuclear power plants can melt down and cause lots of dam damage so you can imagine in the same analogous way the mitochondria which is the nuclear power plant of our cell can basically lead to cell death now when exactly would this be useful well when we discuss embryology we're going to see that the way that we form our fingers on the hand is a result of the fact that our mitochondria is capable of killing off that cell and that process is eposis so the way that we're able to basically create our five fingers is a result of eposis now what exactly is calcium signaling well basically the outer membrane of our mitochondria can associate with the membrane of the endoplasmic reticulum and that creates different types of important signaling Pathways using calcium now cellular differentiation is another important Concept in embryology so we'll talk about that when we get to embryology it's basically the ability of mitochondria to direct the differentiation of cells from an undifferentiated cell to a differentiated cell such as for example a muscle cell or a nerve cell now what exactly is the structure of a single mitochondrion so each mitochondrion consists of two phospholipid bylayer membranes one is called the outer membrane so we have the outer membrane as well as an inner membrane now notice that the inner membrane creates these infolds and these infolds are known as chrisy and the reason we create these infolds is to increase the surface area of our inner membrane to basically be able to fit many more proteins into our inner membrane because proteins in the inner membrane are very important as we'll see in just a moment now the space between the outer membrane and the inner membrane is known as the intermembrane space or the per mitochondrial space and finally the innermost space within our mitochondria the space that is basically below our inner membrane is known as the mitochondrial Matrix and that is also a very important region as we'll see in just a moment that's the location where the crep cycle also known as the citric Cycle takes place so let's begin by basically looking at every single one of our structures and see why each structure is important let's begin with the outer membrane now the outer membrane is a phospholipid bilayer it's basically the same type of membrane that is found around that cell so the outer membrane is a phospholipid bilayer and it contains a protein lipid composition that is very similar to the protein lipid composition of the plasma membrane of the cell now the outer membrane also contains special type of large integral proteins proteins that span the entire outer membrane known as porin and these porn can basically um allow certain types of small molecules to pass through via the process of facilitated diffusion so down the electrochemical gradient without using any type of energy source so for instance these large integral proteins can allow the molecule called pyruvate as well as nadh to pass through our outer membrane so when we discuss the process of glycolysis when we basically break down glucose we produce the molecule pyruvate as well as nadh and pyruvate and nadh can basically be broken down further inside the mitochondrial Matrix so it's very important for these molecules to actually be able to pass through the outer membrane with ease and that's exactly why we have these proteins called porins that act as carrier proteins and transport these molecules into our intermembrane space now let's move on to our intermembrane space so also known as the per mitochondrial space this is the region between the outer membrane and our inner membrane this is this region here shown by this Arrow now since the outer membrane is permeable to small ions and molecules that implies that the con conentration of the ions and molecules in a cytool is the same as the concentration of these small molecules and ions inside the intermembrane space now even though the outer membrane is permeable to small molecules and ions it's not permeable to large proteins and so the types of proteins we'll find in a sinuso is different than the type of proteins we'll find in our intermembrane space now let's move on to our inner membrane the inner membrane is arguably one of the most important structures within our mitochondria so the inner membrane contains a much higher protein concentration than the outer membrane and it is impermeable to essentially all our ions and molecules and because of that it contains a multitude of proteins that act as integral prot proteins to basically carry the molecules from our intermembrane space into the mitochondrial Matrix for example the nadh molecule that can easily pass through the poring integral proteins found on our outer membrane cannot pass through our inner membrane and a special type of protein that uses ATP has to basically carry that NAD Mo NAD D molecule from our intermembrane space into that mitochondrial Matrix where it is then basically broken down to produce the ATP molecule to basically create the electrochemical gradient and produce our ATP molecules so we see that our inner membrane is impermeable to essentially all ions and molecules and contain a multi proteins that shuttle molecules into and out of our Matrix now it also contains a series of proteins known as our electron transport chain or Etc and this these are the series of proteins that are basically responsible for setting up an electrochemical gradient between the Matrix and our intermembrane space for our ATP synthes uh protein to basically create that ATP molecule that we use as our energy source now let's move on to our mitochondrial Matrix so the mitochondrial Matrix is this area here and it contains the majority of the proteins found in our mitochondria and most of these proteins basically act as enzymes in our citric acid cycle in the crep cycle which basically involves the breaking down of pyruvate using our molecule acetal co-enzyme a as well as other things to basically create our ATP molecules with the help of the electron transport chain now the mitochondria also contain or the mitochondrial Matrix also contains the mitochondrial DNA along with the mitochondrial RNA