What is Hb's fractional saturation when p 50 = 26 torr, n H = 3, and p O 2 = 100 torr, a typical p O 2 in the lungs?

So this practice problem is asking what is hemoglobin's fractional saturation when the p50 is equal to 26 tors, the hill constant is equal to 3, and the partial pressure of oxygen is equal to 100 tors, a typical partial pressure of oxygen in the lungs. And, we've got these 5 potential answer options down below. Now, what I want you guys to notice is that this practice problem is pretty much exactly the same as the previous practice problem. The only real difference is that we're increasing the partial pressure of oxygen from 25 tors in our previous problem up to 100 tors in this problem. And so we'll be able to talk more, about this typical partial pressure of oxygen in the lungs later in our course. But for now because we wanna calculate the fractional saturation we need to use the equation for the fractional saturation of hemoglobin, which is right here and it's pretty much exactly the same as before except we're raising all these components to the power of the Hill constant, which is given to us as 3. So, we have everything that we need up above, so all we need to do is just plug in these variables. And so, again, the concentration of ligand is gonna be the partial pressure of oxygen, which is a 100 tors. So we can put in 100 tors, in the top here and this is gonna be raised to the power of the hill constant which is given to us as 3. So, we can cube this. And then this is all gonna be over again, 100 tors, cubed again, and then we can add this to the k d. And so the k d recall is the same thing as the p fifty. And so, it's going to be 26 tours. And then, of course, we're gonna have to cube this as well, to the power of the Hill constant. And so, now, all we really need to do is, plug all of this into our calculator. So if you do 1 100 cubed divided by the sum of 100 cube plus 26 cubed, you'll get our answer which is equal to about 0 point 98 and this is gonna be the fractional saturation that we were looking for all along, which matches with answer option D. So, we can indicate that D here is the correct answer for this problem. Now, what I want you guys to notice is that there's a much larger increase in the fractional saturation or there's a much larger fractional saturation when we increase the partial pressure of oxygen to a 100 tors. If you compare, this answer with the answer with our previous practice problem. And again, we'll be able to talk more about this idea later in our course when we talk about, the conditions in the lungs and the tissues. So, this concludes this practice problem and I'll see you guys in our next video.

Table of contents

Skip topic navigation

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m