Theme 4 Part 4 Ph Regulation Flashcards
What does pH affect
What does it need to be
Charge of the protein
Changes shape of the protein
Affect solubility function and enzymatic activity of the proteins
A specific value 6.8-7.7
Has a tight regulation, anything outside range is lethal
Since oxygen concentration is greater in air than in blood what does this mean
Oxygen transfers to the blood
Where is the partial pressure of oxygen greater? In body tissues or in lungs?
Lungs (alveoli)
When you have high oxygen saturation what does this mean
Since it plateaus at a certain point of hemoglobin oxygen saturation, the increasing partial pressure of oxygen (x axis) doesn’t affect the percent of oxygen saturation in hemoglobin
Even with lower partial pressure of oxygen, you still have a high level of oxygen saturation
Good for when breathing fast
When does the steep component of the oxygen saturation and partial pressure curve tell us
Any change of partial pressure in this region results in double or triple yeild of oxygen that are releasing by hemoglobin and go into cells that use it for metabolism
What is involved in acid base (ph) regulation
When co2 is made, it combines with H2O to make carbonic acid
Since carbonic acid is a weak acid, is dissociate into HCO3- (bicarbonate) and H+
The PH regulation involves this dissociated H ion and equilibrium to shift left or right
This is done through buffering systems
What are the three buffering systems
Pulmonary
Renal
Chemical buffering
What is pulmonary buffering
Has to do with ventilation (breathing)
Increased ventilation/decreased can alter the plasma co2 to buffer changes in ph
Occur in minutes
What is renal buffering
Excretion/ diffusion of carbonate (HCO3-) or H+
This takes hours to days
What is chemical buffering
Through the blood plasma
Happens very fast
How does respiration regulate blood levels of carbonic acid in body tissues
First a hemoglobin pigment is carrying oxygen
at this point oxygen is higher in the blood than in the cells, co2 higher in cells
Once co2 is in the blood it combines with water from blood plasma to make HCO3- and H+. The creation of H+ decreases the ph in the blood (more acidic)
The buffer system comes in by hemoglobin binding to this new h ion, so more co2 can come in to the blood without changing the ph too much
How does respiration regulate blood levels of carbonic acid in the lungs
The hemoglobin is carrying co2 back to the lungs.
The hemoglobin releases the h ion then combines with bicarbonate to make co2
Then co2 leaves the blood to go to lungs
What happens during acidosis
Ph decreases so:
Brain and receptors stimulates
Respiration rate increases so co2 goes to lungs
Co2 in blood decrease (co2 leaves blood after forming to make h go down)
H2CO3 in blood decreases
All to make ph increase (less h atoms)
What happens during alkalosis
Ph increases so:
Brain and receptors stimulates
Respiration rate decreases so co2 stays in blood to react with h2o and make h+
Co2 in blood increase (co2 stays in blood to make h go up)
H2CO3 in blood increases
All to make ph decrease (get more h atoms)
How long does take to reach homeostasis in ph for the exrectory system?
Hours to days
