Section 8 - Exchange and transport in animals - Exchange of materials, surfaces, alveoli and respiration Flashcards
What do cells need oxygen for?
Aerobic respiration
How do gases move between cells of an organism and the environment?
How is water taken up by cells? And what is also taken along with it?
Gases move by diffusion
Water taken up by osmosis along with dissolved food molecules and mineral ions
What is a waste product by animals from proteins and how is it removed from the body?
Urea diffuses from cells to blood plasma for removal from body by kidneys
What does an organism’s large surface area:volume ratio suggest?
How easy it is for it to exchange substances with its environment
What is the job of the lungs?
To transfer O2 to blood and to remove waste CO2 from the blood
Where does gas exchange take place in the lungs and how does it occur?
Alveoli
Blood from body arrives to alveoli with lots of CO2, which diffuses from blood to alveoli. O2 from air in alveoli diffuses to blood, where low concentration.
4 ways alveoli are specialised to maximise diffusion of gases?
Moist lining for dissolving gases
Good blood supply to maintain concentration gradients of O2 and CO2
Very thin walls to minimise distance gases have to move
Enormous surface area
What is respiration? Type of reaction and two types of respiration?
Process of transferring/releasing energy from breakdown of glucose
Exothermic reaction
Aerobic and anaerobic respiration
Equation for aerobic respiration in both plants and animals?
Glucose + oxygen –> Carbon dioxide + water
C6H12O6 + 6O2 –> 6CO2 + 6H2O
What causes formation of lactic acid?
Cells respiring without oxygen so glucose isn’t broken down properly
Word equation for anaerobic respiration in animals and equation for plants?
Animals : glucose –> lactic acid
Plants: glucose –> ethanol + carbon dioxide
