Gas exchange - organisms Flashcards
What is cellular respiration?
A process occurring in all living cells that releases energy in the form of ATP
It involves the oxidation of substrate molecules such as glucose.
What is the waste product of aerobic respiration?
Carbon dioxide
Aerobic respiration requires oxygen to occur.
What is gas exchange?
The process by which gases are exchanged between living organisms and their environment
This includes oxygen uptake and the release of carbon dioxide.
What do plants absorb and release during photosynthesis?
Absorb carbon dioxide and release oxygen
This process occurs during the day.
What factors determine the rate of diffusion during gas exchange?
- Size of the respiratory surface
- Concentration gradient
- Diffusion distance
A larger surface area and shorter diffusion distance increase the rate of diffusion.
How do small, unicellular organisms like amoeba achieve gas exchange?
They have a large surface area compared to volume and a short diffusion distance
This allows sufficient oxygen supply for their functions.
What changes occur in gas exchange as an organism increases in size?
- Smaller surface area to volume ratio
- Greater diffusion distance
Larger organisms cannot rely on diffusion alone for oxygen supply.
What do large, active organisms require for gas exchange?
Specialised organs
They need more oxygen to meet metabolic demands.
What properties do gas exchange surfaces require to maximize diffusion?
- Permeability
- Thin tissue layer
- Presence of moisture
- Large surface area
These properties facilitate the diffusion of gases.
How is a steep concentration gradient maintained for gas exchange?
- Dense network of blood vessels
- Good transport medium of blood
- Continuous blood flow
- Ventilation with air or water
This ensures efficient diffusion of oxygen and carbon dioxide.
