Hemoglobin is a protein which binds oxygen in the lungs and releases it in the capillaries. Interestingly, your body controls this intake and drop off of oxygen by having different pH’s at the two locations. Instructions: For this presentation, your goal is to walk the audience through how oxygen binds to heme (and if any structural changes occur) along with explaining the binding capacity of oxygen to heme in the lungs and how that differs from that in the capillaries. Also explain how CO2 interacting with water can affect the pH of the capillaries. Feel free to use images from the book or the internet to illustrate your point. Presentations should be around 5-10 minutes.

Oxygen binds with Heme though cooperate binding.This means that as the oxygen molecule binds to the first of the 4 heme groups,it weakened the intermolecular forces, holding the heme group,causing structural change in the Hb molecule.

This  increases the affinity of Hb for more oxygen.Therefore facilitating easy binding of the second oxygen atoms.The 3rd will be faster,while the  the binding of the 4th Oxygen atom is the fastest.This is cooperative binding.

The oxygen binding to the heme group in the lungs at high partial pressure  of oxygen (with low partial pressure of CO2)shifts the dissociation curve for oxygen to the left, so that the heme group  hold oxygen molecule tight and transport this to be released in the tissues. The high  partial pressure and concentration of CO2 at the tissues enable the unloading of Oxygen.This is called Bohr's effects.Here ( tissues) the curves shifts to the right for Hb to unload O2.

When CO2 dissolve in  water in the blood,it dissolves in water in the presence of an enzyme carbonic  anhydrase to form H2CO3. This is unstable and dissociate into H+ and HC03-

The H+ increases the acidity of the blood, and the blood capillaries.Thus it increases the acidity of the capillaries.However, this is mopped by Hb to form heamoglobinic acid.(HHB).Thus it  acts as a buffer.

With the presence of Oxygen, Hb releases oxygen it was carrying to the cells. Bohr' effects

The HCO3- from above diffuses from the blood into the blood plasma, to be carried in solution to the lungs, to release oxygen.CI- from the plasma diffuses back into the blood to balance the electronegativity.This is chloride shift.

Explanation:

i would say it is

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!