Measurements of oxygen binding by whole human blood, at 37oC, at pH 7.4, and in the presence of 40mm of CO2 and normal physiological levels of BPG (5 mmol/L of cells), give the following:
PO2 (mm Hg) = 10.6, 19.5, 27.4, 37.5, 50.4, 77.3, 92.3
% saturation (=100 x Theta) = 10, 30, 50, 70, 85, 96, 98
a). From these data, construct a binding curve, and estimate the percent oxygen saturation of blood at
(1) 100 mm Hg, the approximate partial pressure of O2 in the lungs, and
(2)30 mm Hg, the approximate partial pressure of O2 in venous blood.
b). Under these conditions, what percentage of the oxygen bound in the lungs is delivered to the tissues?
Please help me start this out.
No one has helped you because, unfortunately, we are don't have any teachers available for that subject at present.
It looks to me like you should plot the points and draw a smooth curve through them, read off the values of % saturation at 100 mm and 30 mm Hg, and (for part b) take the ratio of the two values, and expfress it as a percent.
Sure, let's start by constructing a binding curve using the given data. We can plot the % saturation on the y-axis and the PO2 values on the x-axis:
PO2 (mm Hg) | % saturation
------------------------
10.6 | 10
19.5 | 30
27.4 | 50
37.5 | 70
50.4 | 85
77.3 | 96
92.3 | 98
Now, we can connect the data points with a smooth curve to get the binding curve.
Next, let's estimate the percent oxygen saturation of blood at 100 mm Hg and 30 mm Hg. We can do this by finding the corresponding % saturation values on the binding curve.
(1) At 100 mm Hg, the approximate partial pressure of O2 in the lungs, we can see from the binding curve the % saturation is around 98%.
(2) At 30 mm Hg, the approximate partial pressure of O2 in venous blood, we can estimate the % saturation to be around 50%.
Moving on to the second part of the question, we need to determine what percentage of the oxygen bound in the lungs is delivered to the tissues.
To do this, we need to compare the % saturation at 100 mm Hg (98%) with the % saturation at 30 mm Hg (50%).
The oxygen bound in the lungs is approximately 98% saturated, while in venous blood, it drops to around 50%. Therefore, the percentage of the oxygen bound in the lungs that is delivered to the tissues is the difference between the two, which is 98% - 50% = 48%.
So, under these conditions, approximately 48% of the oxygen bound in the lungs is delivered to the tissues.
I hope this helps! Let me know if you have any more questions or if there's anything else I can do for you.
To construct a binding curve, we can plot the percent saturation of oxygen (Y-axis) against the partial pressure of oxygen (X-axis). Here are the data points provided:
PO2 (mm Hg) = 10.6, 19.5, 27.4, 37.5, 50.4, 77.3, 92.3
% saturation (=100 x Theta) = 10, 30, 50, 70, 85, 96, 98
Using this data, let's plot the points on a graph:
PO2 (mm Hg) | % saturation
_______________________
10.6 | 10
19.5 | 30
27.4 | 50
37.5 | 70
50.4 | 85
77.3 | 96
92.3 | 98
Now, connect the points with a smooth line to obtain the oxygen binding curve.
To estimate the percent oxygen saturation of blood at certain partial pressures of oxygen, we can read the curve at those points.
a)
(1) At 100 mm Hg, read the % saturation from the curve.
(2) At 30 mm Hg, read the % saturation from the curve.
b) To determine the percentage of oxygen bound in the lungs that is delivered to the tissues, we need to compare the % saturation at the arterial and venous levels (assuming nearly 100% oxygen saturation in the lungs). We can calculate:
Percentage of oxygen delivered = (% saturation in arterial blood - % saturation in venous blood) / (% saturation in arterial blood)
I hope this helps you get started. Let me know if you have any further questions!
To construct a binding curve and estimate the percent oxygen saturation at different partial pressures of oxygen, you can use the given measurements of PO2 and % saturation.
a)
First, plot the data on a scatter plot with PO2 values on the x-axis and % saturation values on the y-axis. Connect the points to create a curve. This curve is known as the oxygen dissociation curve.
Once you have the binding curve, you can estimate the percent oxygen saturation at different partial pressures of oxygen.
(1) To estimate the percent oxygen saturation at 100 mm Hg (approximate partial pressure of O2 in the lungs), find the corresponding point on the x-axis (PO2) and draw a vertical line up until it intersects with the binding curve. From this point on the curve, draw a horizontal line to the y-axis (percent saturation) to determine the estimated percentage of oxygen saturation at 100 mm Hg.
(2) To estimate the percent oxygen saturation at 30 mm Hg (approximate partial pressure of O2 in venous blood), repeat the process above by finding the corresponding point on the x-axis and drawing a vertical line up until it intersects with the binding curve. From this intersection point, draw a horizontal line to the y-axis to determine the estimated percentage of oxygen saturation at 30 mm Hg.
b)
To calculate the percentage of oxygen bound in the lungs that is delivered to the tissues, you need to compare the percent saturation at the partial pressure of oxygen in the lungs (PO2 = 100 mm Hg) with the percent saturation at the partial pressure of oxygen in venous blood (PO2 = 30 mm Hg).
Calculate the difference in percent saturation between the two values and divide it by the maximum possible difference in percent saturation (100% - percent saturation at 30 mm Hg). Multiply the result by 100 to convert it to a percentage.
This will give you the percentage of oxygen bound in the lungs that is delivered to the tissues.