Chapter 44 - Gas Exchange and Circulation Pt. 1

Biology 1107 with Abbott at University of Connecticut

About this deck

By: Zach Pierce
Textbook: Biology (Seventh Edition, 7th Edition Hardcover w/ CD INCLUDED)
Created: 2011-10-24
Size: 16 flashcards
Views: 36

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what affects the amount of gas in a solution?

solubility of the gas in water

temperature of the water

presence of other solutes

partial pressure of the gas in contact with the water

Organs of gas exchange

Skin (diffusion)

Gills

Lungs

what makes countercurrent flow in fish gills extremely efficient at extracting oxygen from water?

it ensures that a difference in the partial pressure of oxygen and carbon dioxide in water versus blood is maintained over the entire gas-exchange surface

Describe the movement of air through air passageways to the alveolus

Nose/Mouth --> Trachea --> Bronchi --> Bronchioles --> alveoli

negative pressure breathing

increasing the volume of the chest cavity and thus lowering the pressure which allows for air to be pulled into the lungs

dead space

portions of the air passages that do not have a respiratory surface

how is breathing controlled?

pH detectors in the medullary respiratory center cause the breathing rate to increase in response to exercise

explain how oxygen moves from the alveolus to the blood

diffuses across the wall

does this because the blood has a smaller P_O2 than what the P_O2 is in the alveolus

heme

a nonprotein group that is binder to the four polypeptide chains found in hemoglobin

contains an iron ion that can bind to an oxygen molecule

why is the the oxygen-hemoglobin equilibrium curve S-shaped?

because the binding of each successive oxygen molecule to a subunit of the hemoglobin molecule causes a conformational change in the protein that makes the remaining subunits much more likely to bind to oxygen (*called cooperating binding*)

why is cooperative binding important?

it makes hemoglobin sensitive to changes in the P_O2 of tissues

Bohr shift

shape changes in hemoglobin resulting from a decrease in PH and an increase in temperature cause hemoglobin to be more likely to release O₂ at any given value of tissue P_O2

carbonic anhydrase

catalyzes the formation of carbonic acid from carbon dioxide in water

how is most CO₂ transported in blood?

in the form of HCO₃^- (the bicarbonate ion)

why is the carbonic anhydrase activity in red blood cells so important?

the protons produced by the reaction induce the Bohr shift which makes hemoglobin more likely to release oxygen

the partial pressure of CO2 in blood drops when it is converted to soluble bicarbonate ions which maintains the PP gradient

how does hemoglobin act as a buffer?

when it is not carrying oxygen molecules, it has a high affinity for protons which are present because of the dissociation of carbonic acid

About this deck

By: Zach Pierce
Textbook: Biology (Seventh Edition, 7th Edition Hardcover w/ CD INCLUDED)
Created: 2011-10-24
Size: 16 flashcards
Views: 36

About StudyBlue

“I have used this website for three exams, and I see a huge difference in my test results.”
Naj