Attracting Abundance
- 115 -
The Law
Belief - XXVII
We have learnt about the structure of the membrane in the posts on cellular biology. I will make a brief recap and also give more inputs on Integral Membrane Proteins (IMP). This has a purpose.
The cellular membrane comprises of two major chemical constituents: phospholipids and proteins. The phospholipid has a polar phosphate head with two non-polar legs. Remember our analogy of a lollipop with two sticks. (Note: The chemical bonds between the atoms of a polar molecule carry either positive charge and/or negative charge). This polarity enables the polar molecules to attract or repel other polar molecules. Because of their polarity, the polar molecules are water loving or hydrophilic as water molecules are also polar. Similarly, the lipid legs, being non-polar, hate water and are called hydrophobic. The membrane comprises of two layers of phopholipids, stacked one over the other in such a way that the polar heads are exposed to intra-cellular and extra-cellular environment, both of which contain lot of polar substance including water. The non-polar lipid legs are protected from coming into contact with the intra-cellular and extracellular environment by the heads. So any polar molecule will not find access from the cytoplasm to the extracellular environment and vice versa because of the resistance created by the non-polar layer of lipid legs. Had the structure of the membrane been left like this by nature, the cells would have starved and died as no nutrient molecule could have found its way to the cytoplasm as almost all nutrients are polar, and the non-polar lipid layer does not permit trespassing of polar molecules through it. This restriction has one advantage though; it ensures that the inner cell is not bambarded indiscriminately by polar molecules. Nature built in the IMPs in the membrane layer to see that the desired signals and nutrient could flow into the intra-cellular space from the extra-cellular environment and as well flow out from the intra-cellular environment to extra-cellular environment. there are a huge number of proteins in the membrane. Each protein is like a doorway with a bouncer monitoring the doorway. Only those authorized to go in or go out can do so. Also each protein is specific to the type of traffic it permits. A member of audience can not use a doorway meant for entry and exit of the performers. The audience have to go to a separate doorway earmarked for them.
The IMPs are categorized into two types; receptors and effectors. Reecptor proteins are the sense organs of the cell as we have eyes, ears, nose etc as our sense organs. Which receptot protein will sense what type of signal is also specified. Some receptor proteins extentd into intra-cellular to monitor the status of the inner cell environment. Other proteins portrude towards the extra-cellular environment to see what is going on outside the cell. Some receptor proteins sense the physical signals like the presence of molecules of estrogen, histamine, penicillin etc. Some receptors sense the vibrational energy fields such as light, sound, electro-magnetic filed, radio frequency etc. When the receptor proteins sense these signals, the charge carried in the receptor proteins changes due to the signal molecules attaching to the receptor proteins or the energy fields. As the charge of the receptor protein changes, its shape changes and it flexes. Thus the cells are impacted not only by the physical signals but also by invisible energy field. I am a firm believer in the energy field created by though which can influence other substance: physical and subtle. It took time, lots of it, to come to terms with this truth as I too was shackled by the Newtonian physics. Once I realized this truth and applied it, the results were astonishing. To discuss this now will make me go off on a tangent as it requires understanding concepts of quantum physics.
As mentioned earlier receptor proteins provide an awareness of extra-cellular and intra-cellular environment. Cells engage in response to these signals through effector proteins. So receptor proteins sense and effector proteins respond.
As there are different type of receptor proteins foe sensing different signals, so are there different types of effector proteins for differnet types of responses. Transport proteins are one such type of effector proteins which transport molecules and information from intra-cellular space to extra-cellular space and vice-versa through a channel protein. The othe types of effector proteins are cytoskeletal proteins, enzymes which can breakdown or synthesize molecules, etc. The IMPs provide signals that control the binding of regulatory proteins that form the sleeve around the DNA. So the receptor proteins sense signals from intra-cellular and extra-cellular environment based on which the effetor proteins generate responses, one of which is to activate the regulatory proteins which unwinds and reveals the DNA code. This further leads to reading of the DNA codes for making new proteins to replace the worn out proteins. Hence genes do not control their own activity, it is done by environmental signals. Also the cell operations are not controlled by the genes but by environmental signals.
It is the membrane, which inter-acting with the environment, produces intelligent action, and is a likely candidate as the brain of the cell. With this hypothesis, experiments were carried out in which the membrane was removed from the cell. The cell died. If either the receptor proteins or effector proteins are removed, the cell becomes comatose - it becomes brain dead. The cells needs a healthy membrane with both receptor and effector proteins intact.
We have learnt that the number of genes in an organism does not define the organism's evolutionary scale. A higher form of life need no have more genes than a lower form of life. The latest estimate for number of genes in a human being hovers around 19,000 as against 24,000 in a rodent. Evolution is really the story of maximization of receptor-effector proteins, the intelligent units of membrane. Larger the area of the membrane of the cell, more can a cell accommodate receptor-effector proteins, which then imparts greater intelligence to the cell.
It is hypothesized that eukaryote cells have evolved from prokaryote cells. The prokaryote cell is the most primitive form of life on this planet. The membrane of the prokaryote cells also contains proteins but the function these proteins is to discharge the most basic tasks: respiration. digestion, and excretion. With the evolution of the eukaryote cells, these basic functions were pushed down to other organelles inside the cell, thus freeing up area in the membrane for accommodating larger numbers of receptor-effector proteins. Also the size of the cells became larger increasing the surface area of the membrane further which helped in accommodating even larger numbers of receptor-effector proteins.That increased the awareness of the eukaryote cells and also increased their capability for larger number of responses for its survival. However the thinness of the membrane - seven millionth of a millimeter - limited the scope of cells becoming larger beyond a limit to prevent it from bursting. A single eukaryote cell's limit of intelligence was reached. Evolution of higher life forms required greater levels of awareness and more complex responses. The cells found a solution - in probably 3 billion years after the first life on planet - when they decided to form communities and that gave birth to multi-cellular organisms. Initially these communities were loose or shall we say that the cells in the community were less co-operative with one another. As the complexity of functions increased, the cells evolved a new strategy. A group of cells took over the tasks of what the receptor-effector proteins were doing in a single cell by forming a nervous system which served the entire organism. Another group of cells formed the lungs for providing respiration service to the entire organism; this function was carried out by the mitochondria in a single cell. Another group of cells formed tissues and muscles for motility which function was carried out be the interaction of proteins in the cytoplasm in a single cell.
What next? Has the evolutionary ladder peaked with the evolution of life in human form? Or do the cells have more tricks up their sleeve to add the next step to the evolutionary ladder? Only time will tell.
Namaste
See you next time
Prabir
As mentioned earlier receptor proteins provide an awareness of extra-cellular and intra-cellular environment. Cells engage in response to these signals through effector proteins. So receptor proteins sense and effector proteins respond.
As there are different type of receptor proteins foe sensing different signals, so are there different types of effector proteins for differnet types of responses. Transport proteins are one such type of effector proteins which transport molecules and information from intra-cellular space to extra-cellular space and vice-versa through a channel protein. The othe types of effector proteins are cytoskeletal proteins, enzymes which can breakdown or synthesize molecules, etc. The IMPs provide signals that control the binding of regulatory proteins that form the sleeve around the DNA. So the receptor proteins sense signals from intra-cellular and extra-cellular environment based on which the effetor proteins generate responses, one of which is to activate the regulatory proteins which unwinds and reveals the DNA code. This further leads to reading of the DNA codes for making new proteins to replace the worn out proteins. Hence genes do not control their own activity, it is done by environmental signals. Also the cell operations are not controlled by the genes but by environmental signals.
It is the membrane, which inter-acting with the environment, produces intelligent action, and is a likely candidate as the brain of the cell. With this hypothesis, experiments were carried out in which the membrane was removed from the cell. The cell died. If either the receptor proteins or effector proteins are removed, the cell becomes comatose - it becomes brain dead. The cells needs a healthy membrane with both receptor and effector proteins intact.
We have learnt that the number of genes in an organism does not define the organism's evolutionary scale. A higher form of life need no have more genes than a lower form of life. The latest estimate for number of genes in a human being hovers around 19,000 as against 24,000 in a rodent. Evolution is really the story of maximization of receptor-effector proteins, the intelligent units of membrane. Larger the area of the membrane of the cell, more can a cell accommodate receptor-effector proteins, which then imparts greater intelligence to the cell.
It is hypothesized that eukaryote cells have evolved from prokaryote cells. The prokaryote cell is the most primitive form of life on this planet. The membrane of the prokaryote cells also contains proteins but the function these proteins is to discharge the most basic tasks: respiration. digestion, and excretion. With the evolution of the eukaryote cells, these basic functions were pushed down to other organelles inside the cell, thus freeing up area in the membrane for accommodating larger numbers of receptor-effector proteins. Also the size of the cells became larger increasing the surface area of the membrane further which helped in accommodating even larger numbers of receptor-effector proteins.That increased the awareness of the eukaryote cells and also increased their capability for larger number of responses for its survival. However the thinness of the membrane - seven millionth of a millimeter - limited the scope of cells becoming larger beyond a limit to prevent it from bursting. A single eukaryote cell's limit of intelligence was reached. Evolution of higher life forms required greater levels of awareness and more complex responses. The cells found a solution - in probably 3 billion years after the first life on planet - when they decided to form communities and that gave birth to multi-cellular organisms. Initially these communities were loose or shall we say that the cells in the community were less co-operative with one another. As the complexity of functions increased, the cells evolved a new strategy. A group of cells took over the tasks of what the receptor-effector proteins were doing in a single cell by forming a nervous system which served the entire organism. Another group of cells formed the lungs for providing respiration service to the entire organism; this function was carried out by the mitochondria in a single cell. Another group of cells formed tissues and muscles for motility which function was carried out be the interaction of proteins in the cytoplasm in a single cell.
What next? Has the evolutionary ladder peaked with the evolution of life in human form? Or do the cells have more tricks up their sleeve to add the next step to the evolutionary ladder? Only time will tell.
Namaste
See you next time
Prabir
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