KS3 LUNGS, GAS EXCHANGE AND RESPIRATION

• What is the primary function of the lungs?

  To get oxygen from the air into blood
• Why do cells need oxygen?

  For cellular respiration to produce energy
• What is the trachea also known as?

  Windpipe
• What happens to air after it passes through the trachea?

  It divides between the two bronchi
• What are the small sacks in the lungs called?

  Alveoli
• How are alveoli adapted for gas exchange?

  They have a large surface area and thin walls
• Why does the thin layer of cells in alveoli increase diffusion rate?

  It creates a short diffusion pathway
• How many alveoli do adults have approximately?

  Hundreds of millions
• What would happen if all alveoli were spread out flat?

  They would cover half a tennis court
• Why are the alveolar walls moist?

  To allow gases to dissolve for diffusion
• What is the concentration gradient for oxygen in the alveoli?

  Higher in alveoli than in blood
• How is carbon dioxide transported in the blood?

  It is dissolved in the blood plasma
• What happens to deoxygenated blood in the lungs?

  It enters the capillaries for oxygenation
• What changes in breathing rate occur during exercise?

  Breathing rate increases
• How do you calculate breathing rate?

  Divide breaths taken by time in minutes
• If you took 42 breaths in three minutes, what is your breathing rate?

  14 breaths per minute
• What is the main topic of the video?

  Respiration
• What is respiration primarily used for in organisms?

  To release energy from glucose
• What are the key features of alveoli that facilitate gas exchange?

  • One layer of thin cells
  • Large surface area
  • Moist walls for gas dissolution
• What type of reaction is cellular respiration?

  Exothermic reaction
• Describe the process of gas exchange in the lungs.

  1. Oxygen diffuses from alveoli to blood
  2. Carbon dioxide diffuses from blood to alveoli
  3. Oxygenated blood is transported to the body
  4. Deoxygenated blood returns to the lungs
• What does cellular respiration involve?

  Breaking apart glucose molecules
• Why is it incorrect to say energy is created during respiration?

  Energy is transferred, not created
• What is aerobic respiration?

  Respiration with enough oxygen
• Where does aerobic respiration occur in cells?

  In mitochondria
• What is the word equation for aerobic respiration?

  Glucose + Oxygen → Carbon Dioxide + Water
• What is the chemical formula for glucose?

  C$_6$H$_{12}$O$_6$
• What is anaerobic respiration?

  Respiration without oxygen
• When do humans perform anaerobic respiration?

  When sprinting and oxygen is insufficient
• What is the word equation for anaerobic respiration in humans?

  Glucose → Lactic Acid
• Why is anaerobic respiration considered inefficient?

  Glucose is only partially broken down
• What is a toxic byproduct of anaerobic respiration in humans?

  Lactic acid
• What is anaerobic respiration in plants and yeast called?

  Fermentation
• What is the word equation for anaerobic respiration in yeast?

  Glucose → Ethanol + Carbon Dioxide
• How is fermentation used in the baking industry?

  Yeast produces carbon dioxide for bread
• How is fermentation utilized in beverage production?

  Yeast produces ethanol for beer and wine
• What are the two types of respiration?

  • Aerobic respiration
  • Anaerobic respiration
• What are the key points about aerobic respiration?

  • Requires oxygen
  • Most efficient energy transfer
  • Occurs in mitochondria
• What are the key points about anaerobic respiration?

  • Occurs without oxygen
  • Less efficient energy transfer
  • Produces lactic acid in humans
  • Produces ethanol and carbon dioxide in yeast
• What are the practical applications of fermentation?

  • Used in baking for light bread
  • Used in brewing for beer and wine