Exchange and Transport in animals

• What is aerobic respiration?

  Respiration in the presence of oxygen
• What is the overall equation for aerobic respiration?

  C$_6$H$_{12}$O$_6$ + 6O$_2$ ⟶ 6CO$_2$ + 6H$_2$O
• What are alveoli?

  Tiny air sacs in the lungs
• How are alveoli adapted for gas exchange?

  Large surface area, good blood supply, thin walls
• What is anaerobic respiration?

  Respiration without oxygen
• What are the products of anaerobic respiration in animals?

  Lactic acid is produced
• What are the products of anaerobic respiration in plants?

  Ethanol and carbon dioxide are produced
• How does anaerobic respiration compare to aerobic respiration?

  Less energy is formed than in aerobic respiration
• What is the aorta?

  The artery carrying oxygenated blood from the heart
• What is an artery?

  A blood vessel carrying blood away from the heart
• What is the structure of artery walls?

  Thick layers of smooth muscle and elastic fibres
• What are bicuspid valves?

  Valves between the left atrium and left ventricle
• What is blood composed of?

  Red blood cells, white blood cells, platelets, plasma
• What are capillaries?

  Thin, narrow blood vessels connecting arteries and veins
• What is the function of capillaries?

  Site of exchange of substances between blood and tissues
• What is cardiac output?

  Volume of blood pumped out of a ventricle in one minute
• How is cardiac output calculated?

  Cardiac output = heart rate × stroke volume
• What is cellular respiration?

  An exothermic reaction releasing energy from organic compounds
• What is the circulatory system?

  The transport system in animals
• What is a concentration gradient?

  The difference in concentration between two areas
• How does concentration gradient affect diffusion?

  The greater the gradient, the faster the diffusion rate

  
• What is diffusion?

  The net spreading out of particles from high to low concentration
• What is diffusion distance?

  The distance substances must diffuse
• How does diffusion distance affect diffusion rate?

  The smaller the distance, the faster the diffusion rate
• What is a double circulatory system?

  A system where blood flows through the heart twice
• How does blood flow in a double circulatory system?

  Blood is pumped to lungs, then to the body
• What is an erythrocyte?

  A type of blood cell that carries oxygen
• What is the function of haemoglobin in erythrocytes?

  Enables transport of oxygen and carbon dioxide
• What is an exchange surface?

  A surface over which materials are exchanged
• What does Fick’s law state?

  Rate of diffusion is proportional to surface area

  
• What factors affect the rate of diffusion according to Fick's law?

  Surface area, concentration difference, membrane thickness

  
• What is heart rate?

  The number of times the heart contracts in one minute
• What is lactic acid?

  The product of anaerobic respiration in animals
• What effect does lactic acid have on anaerobic respiration?

  It inhibits anaerobic respiration and causes cramp
• What is a lymphocyte?

  A type of white blood cell that produces antibodies
• What is a multicellular organism?

  An organism consisting of more than one cell
• Why do multicellular organisms require an exchange surface?

  They have a small surface area to volume ratio
• What is a phagocyte?

  A type of white blood cell that engulfs pathogens
• What is the function of plasma in blood?

  It carries red blood cells and nutrients
• What are platelets?

  Small fragments of cells involved in blood clotting