 |
|||||||
Intracellular and Extracellular Spaces: Volume and Chemical Control |
|||||||
Multicellular organisms (MCOs), like your body consist of an intracellular and extracellular space both of which are mostly made up of water. By weight, water makes up 60% of the body, 2/3rds inside cells (intracellular fluid (ICF)), and 1/3rd outside cells, (extracellular fluid (ECF)). Not surprisingly, since science assumes the origin of terrestrial life from random chemicals into simple organisms followed by the development of complex ones, took place by the unguided processes proposed by evolutionists, its search for extra-terrestrial life involves finding water.
Not So Fast! To thrive, a MCO must maintain control of the volume and chemical content of its cells (ICF) and extracellular space (ECF). “Chemical content” means the concentration i.e. the amount of a given chemical (like glucose) dissolved in a given volume of fluid (water) in the ICF or ECF. Think of the relationship between volume and chemical concentration as how you control the sweetness of your coffee/tea. The more sugar you put into a given volume of coffee/tea, the higher the concentration and the sweeter it tastes. If it isn’t sweet enough you simply add more sugar to the same volume to increase the concentration. But, if it is too sweet, the only way to lower the concentration is to add more coffee/tea (increase the volume) until it matches your taste preference. This is how chemical concentration and volume relate to each other, whether inside your cup of coffee/tea, or the water inside your body! The same thing applies to the ICF/ECF. The space inside the cells and outside the cells must have the right volume and concentration of chemicals to live and work properly. In a MCO, the chemical content of the ICF is very different from the ECF. This difference must be maintained for proper tissue and organ function, that is, for survival itself. In particular, the ICF has a high concentration of potassium ions (K+ ions) and protein, and a low concentration of sodium ions (Na+ ions). The ECF has a high concentration of Na+ ions and a low concentration of K+ ions and protein. The differences between the volume and chemical content of the ICF and ECF in the human body must be maintained for survival. This means that the mere presence of liquid water (with various chemicals in solution), although necessary for life is not, in and of itself, sufficient for life. To stay alive, MCO life has to have the right amounts of water with the right chemical content in the right places, all the time.
Following the Rules of MCO (Human) Life If cells (ICF) take in too much water, like an overinflated balloon, they expand and die, literally by explosion, because of the physical limits of the surrounding cell membrane. If cells (ICF) don’t have enough water, the reduced volume and increased concentration of chemicals within them causes the metabolic processes to malfunction which results in cell death. If there is too much water outside the cells (ECF), its build-up between them (interstitial space), causes organ malfunction. When this happens in the lungs, it becomes life-threatening, making it harder to breathe, resulting in a major drop in oxygen and rise in carbon dioxide, causing death. If there isn’t enough water outside the cells (ECF) this reduces the blood volume and blood pressure which ultimately compromises blood flow to the tissues and organs, resulting in death.
The Hard Problems Diffusion and osmosis, and the laws of nature that govern them, are two forces which if not accounted for will cause the body to lose control of its ICF and ECF and die.
Hard Problem #1 Diffusion is a passive process of transport across a permeable membrane that allows both the solute and water to pass through. The solute moves from an area of higher concentration to an area of lower concentration until the concentration on both sides of the membrane is the same—the volume of water on either side does not change (see Fig.1).
The ICF has a high concentration of K+ ions and a low concentration of Na+ ions. The ECF has a high concentration of Na+ ions and a low concentration of K+ ions. The cell membrane is the interface between the ICF and ECF. Since the cell membrane is permeable to Na+ and K+ ions (and water) diffusion naturally forces K+ ions to move out of the ICF into the ECF, and Na+ ions to move from the ECF into the ICF. If the force of diffusion is not resisted and allowed to continue to its natural end, the cell will lose control of its chemical content (the K+ ion concentration will decrease too much and the Na+ ion concentration will increase too much) resulting in cell death.
Hard Problem #2 Osmosis is a passive process of transport across a semi-permeable membrane in which water can pass through but the solute can’t. Since the solute can’t move across the membrane, water, instead, moves from an area of lower solute concentration to an area of higher solute concentration until the solute concentration is equal on both sides—the volume of water increases on the side that had the higher solute concentration and decreases on the side that had the lower solute concentration (see Fig. 2)
The ICF has a high concentration of protein. The ECF has a low concentration of protein. The cell membrane, being semi-permeable, allows water to pass through but not most proteins. Diffusion makes K+ ions pass out of, and Na+ ions pass into, the cell The high concentration of protein in the cell also makes water move from the ECF into the ICF. If the force of osmosis is not resisted and allowed to continue to its natural end, water will flood into the cell, it will lose control of its volume and it will die, literally by explosion, because of the physical limits of the cell membrane. If not prevented, this one-two punch of diffusion and osmosis will cause cell/whole body death.
The Innovative Solution Q. What would you have to do if you owned a large boat which was constantly leaking in water? A. Place a bailing pump in it to constantly remove the water or else your boat would sink. This is precisely the type of molecular machine the cells use to maintain control of their volume and chemical content. The cells each have about a million sodium-potassium pumps (see Fig. 3) in the cell membrane. Each sodium-potassium pump is made up of an alpha subunit, consisting of about one thousand amino acids, and a beta subunit, consisting of about three hundred amino acids, all hooked together in a specific order.
Using about one-quarter of the body’s expended energy at rest, these pumps constantly push three Na+ ions out of the cell for every two K+ ions they bring back in, while at the same time preventing water from entering the cell. The million or so sodium-potassium pumps in your over thirty trillion cells are the main reason for the ICF/ECF ratio being 2/3: 1/3. This means that the sodium-potassium pumps are largely responsible for controlling the volume and chemical content of the ICF and the ECF. It’s important to note that if these pumps were to all stop working at the same time, before your body would die from the effect on the ECF, it would die from the effect on the ICF (brain cells).
Evolutionary “Explanations”
Questions
Onward!
|
