5.5: The lungs & gas exchange
What are the tiny blood vessels that surround the alveoli?
Capillaries
What does the nose do to the air before it enters the lungs?
It warms and moistens the air.
What type of respiration takes place when muscle cells do not have enough oxygen?
Anaerobic respiration
During which type of exercise is anaerobic respiration especially useful?
Short, fast/intense exercise, such as sprinting.
Where in the cell does aerobic respiration take place?
Mitochondria
What is the process in the lungs where oxygen in the air is exchanged for carbon dioxide from the blood?
Gas exchange
What is the function of the cartilage rings around the trachea?
They hold the trachea open so it can breathe easily.
What substance is broken down during respiration to release energy?
Glucose
How much energy is released from each glucose molecule during anaerobic respiration?
Less energy is released per glucose molecule than during aerobic respiration but more quickly.
What are the two waste products of aerobic respiration?
Carbon dioxide and water
What are the tiny air sacs where gas exchange takes place?
Alveoli
What are the two tubes that branch from the trachea and lead to the lungs called?
Bronchi
What is the waste product of anaerobic respiration in muscle cells?
Lactic acid
What process uses oxygen to release energy from food in a controlled way inside cells?
Aerobic respiration.
Write the summary word equation for aerobic respiration.
Glucose + oxygen → carbon dioxide + water (+ energy)
What are the specialised cells lining the bronchi called, and what do they help do?
Ciliated cells; they move mucus and trapped microorganisms out of the lungs.
What do the bronchi divide into inside the lungs?
Smaller tubes called bronchioles.
During gas exchange, oxygen and carbon dioxide move by diffusion. Where does each gas move?
Oxygen: alveoli → blood.
Carbon dioxide: blood → alveoli.
What gas is needed for aerobic respiration?
Oxygen
Explain why cells need aerobic respiration.
It releases the energy stored in food so cells can use it for processes such as growth, movement and repair.
Why are there millions of alveoli in the lungs?
To provide a large surface area for gas exchange.
What is the function of the pleura around the lungs?
It produces a liquid that reduces friction, making it easier for the lungs to move as you breathe.
Write the word equation for anaerobic respiration in muscle cells.
Glucose → lactic acid + energy
Why do you continue breathing hard after you stop exercising?
Your body needs extra oxygen to remove/break down the lactic acid in your muscles.
Explain what diffusion is and describe the direction in which particles move during diffusion.
Diffusion is the net movement of particles from an area of high concentration to an area of low concentration.