Pulmonary Biochemistry Week 2 Flashcards
What are the three processes for gas exchange?
ventilation, gas exchange across barriers, perfusion or blood flow
The ______ pH is the pH of the blood and is easily measured
intravascular
What is normal pH for the human body?
7.4; range is 7.35 and 7.45
What is the normal [H+] range in the human body?
40 nM, range between 35 and 45 nm
Life is sustainable within what [H+] ranges
16 nM and 16 nM [H+]
Does the intracellular pH equal the extracellular pH?
No, maintain an imbalance on purpose (intracellular is 7, extracellular is 7.4)
True/False: Acid production originates extracellularly
False, intracellular
The concentration of buffers is 3X higher in the ICF than ECF
True
True/False - Protons freely flow across membranes
FALSE - protons are charged and need active exchangers. This is what Na/H and K/H exchanges are for.
Every acid in the body uses the same H+ ions and they are therefore coupled to one another. This is known as the _______
isohydric principle.
If the collecting ducts of the kidney contain urine at ph=5, what is the [H+] differential between normal blood and the described urine?
Normal blood is 7.4. Therefore difference is 10^2.4 = urine contains 252X more [H+] than blood
When are buffers at their highest capacity?
when at highest concentration and their pKas are closer to the working pH (pH of environment)
What are the three main NON-VOLATILE buffers in ECF?
hemoglobin, plasma proteins, phosphates [in order of buffer capacity]. NOT NH4+ BC TOXIC TO BRAIN
What is the volatile buffer system in the in the ECF? Why is it considered volatile?
bicarbonate, because CO2 gas is involved
Which non-volatile buffer has the highest capacity and why?
hemoglobin because of the abundant histidine side chains and high concentration; 20% of capacity!!!
Hemoglobin is found intracellularly. Why is it considered an extracellular buffer then?
It is found inside RBCs which are permeable to H+ ions. Hgb has a rapid impact on ECF and therefore considered an ECF buffer.
_______ is the most plentiful plasma protein
Albumin
At a concentration of 1mM, _____ is not as important of a buffer in the ECF than in the renal tubular filtrate
phosphate
Non-volatile buffers mitigate pH changes due to changes in _______
volatile acid (CO2)
True/False: Bicarbonate system can mitigate pH changes due to changes in CO2 in the ECF
FALSE -BICARBONATE DOES NOT BUFFER INCREASES IN CO2
What is the most powerful buffer of the ECF?
BICARB!
True/False: CO2 can go across membranes freely
True
How is a manometer used to measure mmHg?
Have U-shaped manometer, put vacuum on one side and measure height of column on other side
True/False: Composition (fractional combination of all gases) in the air is the same at any altitude.
TRUE