Bicarbonate Buffer System

hi everybody dr. Mikey in this video I want to talk about buffers within the body now buffers resist drastic changes in pH we know that our blood has a pH of between seven point three five and seven point four five that's worth putting up peerage of 7.35 to 7.45 and if the blood pH goes below seven point three five it's becoming too acidic if it goes above is becoming too alkyl in ik that means that the concentration of hydrogen ions which dictates the pH is either going to be too much if it goes in this direction too many hydrogen ions or not enough hydrogen ions if it goes in this direction so what happens in the body is if we don't have enough hydrogen ions we need to make more if we do have too many hydrogen ions we need to reduce it and this is what buffers do they resist these drastic changes in pH all right so for example I want to talk about a quick buffer and a buffer that looks like this h2 co3 what this is called is carbonic acid and you should know that the definition of an acid is anything that can donate a hydrogen ion so that means that this carbonic acid can give us a hydrogen ion now if it does give us a hydrogen ion what are we left with if you take 100 out of this we're left with one hydrogen one carbon and three oxygen which is hco3 and because we stole a positive from this it's left with a negative and this is called bicarbonate ion bicarbonate ion and this is our hydrogen ion again it's the concentration of the hydrogen ion that dictates the pH so what we've got here is this a weak acid which donates a small number of hydrogen ions and leaves us with a weak base now the definition of a base is something that can mop up hydrogen ions it can bind to hydrogen ions which means if that can bind to that this is a reversible equation and so this can also go in this direction now what we have here is a very simplistic buffer system where if we don't have enough hydrogen ions the weak acid will split apart and release hydrogen ions if we've got too many it will bind to bicarbonate and go in that direction now our body utilizes this reaction but with the addition of some other parts for example carbon dioxide and water if you bind carbon dioxide and water have a look there's one carbon there's the one carbon two plus one oxygen is three oxygen to hydrogen two hydrogen if you bind carbon dioxide with water you get carbonic acid so let's write these down just for completions sake carbon dioxide and water alright and that can split itself apart to produce these two so that's reversible as well what we've now drawn up here is something called the bicarbonate buffering system and this is one of the most important biological buffers that we have now let me talk about it in regards to how it actually works all right this end of the equation deals with the lungs this end of the equation deals with predominately the kidneys now this is important because when we look at imbalances in regards to pH we can say if something's wrong here it could be metabolic or kidney caused if something's wrong here then it could be respiratory cause and this is going to be the basis of respiratory versus metabolic acidosis or alkalosis right that's for another lecture but let's think about like this let's just say we do not have enough hydrogen ions in the bond if we don't have enough hydrogen ions the pH is going up right so remember it's a reverse logarithmic equation have a look at my previous video about calculating pH right we don't have enough hydrogen ions how do we create more let's have a look carbon dioxide this is a byproduct of respiration breathe in oxygen our mitochondria utilize that oxygen and it produces ATP water and carbon dioxide and we don't like carbon dioxide we want to breathe it out but in order to go from the cells to our lungs to breathe out it has to go in our bloodstream so when carbon dioxide hops in our bloodstream most of our blood streams water inevitably all our carbon dioxide is going to be buying into that water and it will be producing carbonic acid but because carbonic acid is a weak acid hates itself splits itself apart and produces hydrogen ions which means one way we can increase the concentration of hydrogen ions in our body is through the accumulation of co2 how can we accumulate co2 I'll show you hold your breath if you're holding your breath you're not breathing out and this is what happens some individuals who do not have a high enough concentration of hydrogen ions in their blood they may be holding their breath a little bit their breathing will be different let's think of it flipped what if I have too many hydrogen ions well if we have too many the bicarbonate will mop it up and produce carbonic acid which will then split up and produce water and carbon dioxide so if we are acidic and our pH is too low because we have too many hydrogen ions we're not producing more carbon dioxide which means the patient may breathe more so the respiration can be an indication of the blood pH and you can also see if we don't have enough hydrogen ions it goes in this direction if we have too many it goes in this and this is the bicarbonate buffering system

Channel: Dr Matt & Dr Mike

Views: 235,791

Keywords: bicarbonate buffer system, buffers, biological buffers

Id: tC9EfkOe8IQ

Length: 6min 27sec (387 seconds)

Published: Wed Feb 26 2020