Previously we focused on the bohr effect

And we said the bohr effect tells us that the concentration of carbon dioxide and h+ ions in the blood effects

hemoglobins affinity for Oxygen and what the bohr effect ultimately

does is it increases the amount of oxygen that can be absorbed by the

exercising tissue

And it also increases the amount of oxygen that can be absorbed by the blood from the alveoli of our lungs

now another equally important effect is known as the Haldane effect and the held in effect is really the

opposite the reverse of the bohr effect so remember the bohr effect talks about how the

concentration of Co2 and Hydrogen [effect] hemoglobins affinity for oxygen

but what the held in effect does is it takes the opposite perspective it talks about how the

Concentration of Oxygen inside the red blood cell inside our blood actually affects hemoglobins affinity for carbon

[dioxide] and

h+ ions

Now why is the held in effect actually important well as we'll see in just a moment the [howling] effect actually

promotes it

increases the mouth of Carbon dioxide

that can be released by the

exercising tissue to the blood and at the same time it also increases the number of Co2 molecules that can be absorbed by the

Alveoli of the lungs

from [the] blood plasma and to see

What the hell in effect is and how it achieves this let's begin by taking a look at the following diagram

So let's suppose

I'm moving my arm back and forth and as I move [my] arm back and forth the muscle tissue begins to contract and atp

Molecules aren't being produced by those muscle cells

So this is let's suppose that muscle cell and this is the nearby

Capillary that carries the red blood cells now as these cells are

Exercising they require a greater number of Oxygen molecules to produce the atP

And so inside the red blood cells the bohr effect takes place

The it causes hemoglobin to actually unload and release the oxygen which then travels into those

exercising cells

inside the cells in a process called aerobic cellular respiration

We produce the energy

ATp Molecules now these aTp Molecules are used for muscle contraction

[for] the actin contraction

but the Co2

Molecules a byproduct are produced and these cannot be used in any useful way and so the Co2

Molecules are expelled from the cell and they enter the plot of the blood plasma of the capillary the nearby

Capillary now because Carbon dioxide is nonpolar only a very small portion about 5%

Will actually remain dissolved in the blood plasma

The majority of it the rest of it will enter the cytoplasm of the red blood cell

Now once inside the red blood cell what we have to do is we have to convert the carbon dioxide a non-polar

molecule into a polar form namely [the]

Bicarbonate and that's because we want to be able to dissolve the carbon dioxide in the blood

so the majority of the carbon

[dioxide] in the red blood cell will follow this reaction pathway, so a special enzyme. We call carbonic anhydrase

will combine

Carbon dioxide and water to form the carbonic acid Molecule and then the

Carbonic acid being a good acid it will dissociate into h+ ions and the

bicarbonate ions, and this is where the howling effect takes place

so according to the held in effect if we decrease the

[concentration] of Oxygen in the red blood cells so the mouth of Oxygen decreases because it

travels into [the] tissue that exercising tissue and so as this basically

decreases that increases the affinity [of] hemoglobin for the h+ ions

now if we increase

hemoglobins affinity for HP ion's what that means is the

Hemoglobin will begin to bind the h+ ions and so the concentration [of] these free h+ ions

Will begin to decrease because they will begin to bind to the hemoglobin?

Now what will happen as we decrease?

this H+ concentration

Well by lycia clears principle if we decrease the product concentration that will shift the equilibrium

Toward the right side toward the product side and what that means is as

hemoglobin is binding h+ ions we're going to ultimately produce even more of the

Bicarbonate Ions

And it's these bicarbonate ions that are basically the polar form of these co2

Molecules, and so ultimately the [Halden] effect basically

Increases the number of Bicarbonate ions that we can store and dissolve in the blood plasma

Next to the exercising tissue, so once again

the held in effect the fact that as we decrease the

Concentration of Oxygen inside the red blood plot red blood cell as it leaves it enters our tissue cell

that increases hemoglobins affinity to bind h+ ion

So this is what the housing effect tells us and what the hell in effect. Does is it basically?

shifts the equilibrium

To the right side towards the bicarbonate side and that increases the [number] [of] Co2

Molecules in this form that we can store in dissolve in the blood plasma of the nearby

Capillary now we can also represent this effect graphically

So let's take a look at a following graph the y-Axis is basically the Co2

Content in the blood dissolved in the blood and the x-Axis [is] the partial pressure of the carbon dioxide

In that region in the blood now this relatively straight line the black curve basically

Describes how much carbon the young side we can fit we can dissolve

inside the blood at some given partial pressure of Carbon Dioxide

and notice as we

Decrease the

concentration of Oxygen

inside the red blood cell the hell in effect basically

causes A

Leftward shift in this curve, and so the curve moves into the blue position now. Why is that?

Well, let's suppose that this is [the] partial pressure of Carbon Dioxide

inside the exercising tissue

And so we draw a [straight] line going

Upward now in this [particular] case this line basically did not take into consideration

the held in effect and according to this line

We can only fit this amount of co2 inside our blood

But if we do take the [housing] effect into consideration because we do decrease the oxygen content in our blood

Next to the exercising tissue that shifts the curve this way to the left and so the new y coordinate is

This value here [and] notice that what that means is as the oxygen decreases

We can actually store even more carbon dioxide

Inside our blood

Because of what we discussed just a moment ago

So we see that a drop in the oxygen in the red blood cells next to the exercising tissue actually

causes a leftward shift in the curve which means more carbon dioxide

Can ultimately be stored inside the blood and so the tissues will release?

More of [the] carbon [dioxide] because we can fit more of it into that blood plasma

Now we can also use the held in effect to basically describe how the alveoli of the lungs are able to absorb more

more Carbon dioxide

From the blood plasma so the car of the housing effect can also be used to explain how oxygen

concentration affects carbon dioxide unloading into the alveoli of along

so let's take a look at the following diagram so as always we have the red blood cell and this is the

alveolus of our lung

Now what's happening inside our lungs well inside our lungs the oxygen is moving down its

concentration gradient

From the alveolus and into the red blood cell now by the Haldane effect so again we have this

Haldane effect taking place

and

By this howling effect because we increase the concentration

Of oxygen inside our red blood cell we decrease

hemoglobins ability to bind Carbon dioxide and h+ ions

So as oh to binds to hemoglobin it basically decreases

Hemoglobins affinity for h+ in co2 so these two molecules are now released now as we release carbon

dioxide the Carbon dioxide

will begin to dissolve and eventually will leave the red blood cell and into the alveolus now the

Hemoglobin also releases the h+ ions which bind onto the hemoglobin in this area?

What happens to the h+ ions is they essentially?

recombine with the bicarbonate ions that came from the blood plasma

Remember these bicarbonate ions dissolve into the blood plasma at the same time we have the [C]

The Chloride ions going into the red blood cell that's known as the chloride shift and in here the opposite takes place

These basically move into the cell chloride ions leave the cell and this

Recombines with the h+ to reform the carbonic acid and then that basically breaks down into carbon dioxide

and the carbon dioxide

then leaves the cell and

It enters the alveolus and so we see that the held in effect basically promotes

the amount of Co2 that can be absorbed by the

alveolus

so the red blood cells [near] lungs filled with oxygen [the] rise in oxygen causes them to bind to

hemoglobin which in turn decreases

hemoglobins affinity for carbon dioxide and h+ ions and this stimulates

the unloading of Co2 and h+ ions

From the hemoglobin and eventually from the lungs and it enters the alveolus

And then we expel it in the process of exhalation now

So once again the y-Axis is the content of Co2 in the blood

the

X-Axis is the partial pressure of that co2 and now the partial pressure of Co2 will be smaller than in this case

So we're going to be farther to the left side along the curve because in the lungs we have a lower Co2

concentration than in the tissues and so now we're somewhere here now an

Increase in the oxygen content in our red blood cell next to the lungs

Means we have a rightward shift in our curve

So the black curve now shifts this way and what that means is before

this is how much Co2

Was actually stored in the blood but now this is how much Co2 can be stored in the blood so we have

less Co2

That can be stored and dissolved in the blood now if we can dissolve Co2 in the blood

where can the Co2 go well the only place it can actually go is into the

Alveoli of the lungs, and that's exactly what happens as it moves into the Alveoli

We have the pressure difference that expels that co2 to the outside environment

And this is what the haldane effect is the [Halden] affect promotes the release

of co2 from the tissues to [the] blood and also promotes the release of

Co2 from the blood and to the Alveoli of the lungs