3.2 Gas Exchange

• What is the process by which organisms take in oxygen and release carbon dioxide called?

  Gas exchange
• Match the structure of the respiratory system with its function:

  Trachea ↔️ Transports air to the lungs

  Bronchi ↔️ Carry air into the lungs

  Alveoli ↔️ Gas exchange occurs
• Where in the lungs does gas exchange occur?

  Alveoli
• Oxygen is taken in during gas exchange to facilitate cellular respiration.


  True
• The bronchioles are smaller branches of the bronchi that lead to the alveoli
• Gas exchange is essential for cellular respiration and energy production.


  True
• The alveoli are small, thin-walled air sacs that maximize surface area for efficient gas exchange.
• What are the two main methods of oxygen transport in the blood?

  Dissolved in plasma and bound to hemoglobin
• How much carbon dioxide is bound to hemoglobin for transport?

  23%
• 70% of carbon dioxide is converted to bicarbonate ions with the help of carbonic anhydrase
• Gas exchange is essential for facilitating cellular respiration and maintaining metabolic balance
• Match the respiratory structure with its function:

  Trachea ↔️ Transports air to the lungs

  Bronchi ↔️ Carries air into the lungs

  Bronchioles ↔️ Leads to the alveoli

  Alveoli ↔️ Where gas exchange occurs
• Why are the alveoli thin-walled?

  To maximize surface area
• What is the structure of hemoglobin that allows for cooperative binding?

  Tetrameric
• Carbon dioxide is converted to bicarbonate ions with the help of carbonic anhydrase
• What happens to ventilation rate when chemoreceptors detect elevated carbon dioxide levels?

  Increases
• What drives the diffusion of oxygen and carbon dioxide in the lungs?

  Concentration gradients
• Hemoglobin is a tetrameric protein with four heme groups that each bind one oxygen molecule.


  True
• Carbonic anhydrase facilitates the conversion of carbon dioxide to bicarbonate ions for CO₂ transport.


  True
• Steps in the process of carbon dioxide conversion to bicarbonate ions:

  1️⃣ CO₂ diffuses into red blood cells

  2️⃣ CO₂ combines with water

  3️⃣ Carbonic anhydrase converts CO₂ and water to bicarbonate ions

  4️⃣ Bicarbonate ions exit the red blood cells
• Carbonic anhydrase facilitates the conversion of carbon dioxide and water into bicarbonate ions.

  True
• What gas is taken in during gas exchange?

  Oxygen
• The mechanism of gas exchange in the lungs involves diffusion driven by concentration gradients.


  True
• 98.5% of oxygen is transported in the blood bound to hemoglobin
• Cooperative binding in hemoglobin increases its affinity for oxygen.


  True
• Match the chemoreceptor type with its location and stimuli:

  Central Chemoreceptors ↔️ Medulla Oblongata, Cerebrospinal fluid pH

  Peripheral Chemoreceptors ↔️ Aortic and Carotid Bodies, Blood pH, CO₂, O₂