Adaptations of the Lungs
Gases are exchanged by this general process.
What is diffusion?
This process involves air moving out of the lungs.
What is expiration?
Each hemoglobin molecule has ____ haem groups, so can bind to that # of oxygen molecules.
What is four?
High partial pressures of ________ reduce the affinity of haemoglobin for oxygen.
What is carbon dioxide?
This factor moves water vapor away from the leaf, reducing the concentration of water outside the stomata of a leaf and increasing the rate of transpiration.
What is wind?
This structure allows gases to diffuse through it.
What is a permeable membrane?
During inspiration, the ________ contracts and moves downward.
What is the diaphragm?
This term refers to the phenomenon where the binding of one oxygen molecule to a haemoglobin molecule facilitates the binding of additional oxygen molecules.
What is cooperative binding (of oxygen)?
The shift of this curve due to carbon dioxide partial pressures is known as the Bohr shift (or Bohr effect).
What is an oxygen dissociation curve?
This factor increases the concentration of water outside the leaf, resulting in a slower rate of transpiration.
What is humidity?
This adaptation of gas exchange surfaces increases the quantity of gas particles exchanged.
What is a large surface area?
This is the volume of air that moves in and out of the lungs in a normal breath.
What is tidal volume?
Because ____________ has a higher affinity for oxygen than adult haemoglobin, it can bind oxygen at the low partial pressures in the placenta.
What is foetal haemoglobin?
The Bohr shift in the lungs moves the oxygen dissociation curve in this direction.
What is left?
These adaptations of leaf structure are pores which allow gases to enter and exit the leaf.
What are stomata?
The _____ secrete a surfactant which prevents the walls from adhering to each other, providing a moist surface for gas exchange.
What are alveoli?
During inspiration, the volume the thorax _____ (increases/decreases), and the pressure in the lungs ______ (increases/decreases)
What is increases and decreases?
Adult haemoglobin has two alpha and two beta chains of polypeptides, while foetal haemoglobin has two alpha and two ______ chains of polypeptides.
What is gamma?
In respiring tissues, this factor causes a Bohr shift.
What is high partial pressures of carbon dioxide?
This adaptation of leaf structure covers the epidermis cells and reduces the evaporation of water from the leaf.
What is a waxy cuticle?
Alveoli are surrounded by an extensive _________, which maintains high concentration gradients for O2 and CO2 between the blood and alveoli.
What is a capillary bed?
This is the greatest volume of air that can be expelled from the lungs after the deepest possible breath.
What is vital capacity?
Carbonic acid dissociates to form hydrogen carbonate ions and hydrogen ions. This reaction is catalysed by __________.
The hydrogen ion binds to haemoglobin, causing a conformational change, which decreases the affinity of haemoglobin for oxygen.
What is carbonic anhydrase?
In addition to low carbon dioxide partial pressure, this factor results in oxygen binding to haemoglobin at high saturation levels.
What is high oxygen partial pressure?
The irregular shape of these cells increases the surface area for gas exchange. These cells are surrounded by air spaces.
What are spongy mesophyll cells?