2.1 Gas Exchange Systems - uni and multicellular organisms Flashcards
4 components of lungs in order
Trachea
Bronchi
Bronchioles
Alveoli
2 type of cells present in trachea and functions
Ciliated epithelial cell - move mucus out of trachea
Goblet cells - Produce mucus (to trap dirt, particles, debris etc)
What prevents the trachea collapsing
C shaped rings of cartilage
3 Alveoli properties which allow for rapid gas exchange
- Lots of Alveoli
- Good blood through surrounding capillaries
- Thin walls
How does surface area to volume ratio affect rate of gas exchange in organisms
Organisms with a larger surface area to volume ratio have more efficient gas exchange and vice versa
What do larger organisms have that unicellular organism don’t, into order to meet their higher metabolic requirements?
A circulatory system
Where does gas exchange take place in unicellular organisms?
Through surface membrane
As cell size increases what happens to surface area to volume ratio?
SA to V ratio decreases - as surface area is squared volume is cubed. (Volume increases more rapidly than surface area)
What sets up the concentration gradient in a unicellular organisms
- The build up of Co2
How much more ATP (per molecule of glucose) does Aerobic respiration provide than anaerobic
19x
Example of an animal without a specialized exchange surface
Why
- Earthworm
It takes in o2 and expels co2 directory through skin
Gas exchange surface in mammals
Alveoli
What does ventilation help to maintain?
A concentration gradient
What is “partial pressure” used to express?
And what is it measured in?
The concentration of a gas
Kilopascal (KPa)
Explain diffusion of 02 from alveoli into capillaries using partial pressure
- 02 partial pressure in alveoli higher than in capillary
- Concentration gradient drives diffusion
