Question

1. What is the approximate hemoglobin O2 saturation of a blood sample that contains 10 g Hb/100 ml blood and has an O2 content of 10 ml O2/100 ml blood (ignore physically dissolved O2)? Show work

2. About 40% of Ca2+ in the blood is bound to plasma proteins, such as albumin. The [Ca2+] in Bowman’s Capsule is ~ 3 mEq/l, whereas its concentration in the plasma is ~ 5 mEq/l. Why the difference in [Ca2+] between these two compartments? Show Work

3.If the protein in the glomerular filtrate was 0.005 g/100 ml and none of it was reabsorbed, how much protein would be excreted per day, assuming a normal GFR of 180 l/day? Show Work

Answer 1

1) Hemoglobin carries oxygen in the blood and myoglobin stores oxygen in the muscles. They do this by binding eeversibly with oxygen, which forms a weak bond with with the iron(II) ion in heme. The binding of oxygen does not change the oxidationstate of the iron ion2+ therefore Hb and myoglobin are oxygenated rather tahn oxidized. the oxygenated products are known as oxyhemoglobin and oxymyoglobin.

Oxygen saturation of hemoglobin

the binding of oxygen to hemoglobin is a cooperative process. The abilty to bind oxygen is increased by the initial binding of the first oxygen molecule. The first oxygen molecule binds with low affinity, but increases the binding affinity of further oxygen molecules. This results in a sigmoidial or s- shaped saturation curve. The ability of Hb to bind or release oxygen depends on the partial pressure of the oxygen. When the pO2 is high each molecule molecule of Hb can carry its maximum of four oxygen molecules. As the blood circulates around the body, the blood experiences lower levels of partial presasure.At low pO2 the Hb releases some of the oxygen it is carrying. An increase in tempreture reduces the affinity of Hb for oxygen. Therefore Hb more readily releases oxygen at higher tempretures in the cells during high metabolic activity such as excersice.

Ans 2) In the glomerulus there is a mebrane that acts as a filter. When blood blows through the capilleries of glomerulus, beacause of pressure all the substances present in the plasma except the proteins are filtered into bowmen's capsule. protein contain highly albumin which is very heavy molecular weight.This filtrate contain not only the metabolic wastes but also many essential substances like glucose, amino acids whcih are required by the body.

Many essentials substances from the fluid are removed by the cells lining the tubule and returened to the blood. this is known as tubular reabsorption. It is the movement of sustances out of the renal tubules. substances reabsorbed are water, glucose and other nutrients, and sodium and other ions. In plasma is the straw colored liquid composed of 92% water in which the blood cells are suspended.plasma transport materials needed by cells and materials that must be removed from cells: various ions i.e, Na+ , Ca2+, HCO3 etc.

Ans 3) During one minute the total volume of filtrate by all the nephrons in both the kidneys together is 125ml. This is known as glomerular filterate rate. Out of this 125 ml/mim, only about 1ml/min will be excreted as urine.So when filtrate passes through renal tubules, not only the composition of filetrate gets altered, there will be an enormous decrease in the volume((99% volume). Because of this reason, in a normal person the total volume of urine excreted/day is about 1 to 1.5 litres.