Animal and Plant Gas Exchange
How animals and plants get the gases they need
ANIMAL SYSTEMS There’s two types of respiration that animals do. One is breathing, the other is cellular. Plants do the cellular one, but not the breathing one.
What’s the diff?? Internal Respiration AKA cellular respiration! Mitochondria O2 is converted into CO2 Glucose is converted into ATP This happens in the cells!
What’s the diff?? External Respiration Breathing in and out O2 is sucked in by the
nose and mouth O2 travels to lungs
where the blood trades it for CO2
CO2 is breathed out as a waste from Cellular Respiration!
Structures of Respiratory System
Nose and Mouth Breathe in and out
Trachea Air flow travels
through this tube Lungs
Alveoli (air sacs) are the sight of gas exchange
Breathing
So what’s the point?
Function: To breathe in O2 (for
cellular respiration) To exchange O2 for
CO2 To get rid of (breathe
out) CO2
SO…. We do external respiration (breathing) to have reactant gas (O2) for internal respiration (cellular respiration) and to get rid of the waste product (CO2)
How does gas exchange work in Respiratory System?
Tiny blood vessels called capillaries bring blood around the alveoli sacs to exchange gases
What do we need to breathe for?
OXYGEN intake! CARBON DIOXIDE
removal! We have to breathe
so that we can do cellular respiration!!!!
What happens to the CO2 we get rid of???
THINK…PLANTS duh!
RECAP
Questions
What is the difference between the respirations?
Why do we need to have Oxygen?
What happens to the CO2 we breathe out?
What structures actually do the gas exchange?
AND THE BIG QUESTION…
Do you think plants have a way to do gas exchange?
Do you think it works the same way??
Plant System Gas Exchange
PLANTS DON’T BREATHE!!!!
They do cellular respiration, but not the lung one!
They need to have a way to get CO2 and get rid of O2
The Answer??
A LEAF!!
What’s in a Leaf?
Leaf cross section
What’s in a Leaf?
Instead of a mouth for breathing, leaves have stomata
Pores in the underside of the leaf for gas to flow in and out
Also for water to leave!
Stomata
Also called stoma Holes in the leaf Guarded by cells that
control how wide the pore is (Guard Cells)
Important for gas movement
AND WATER loss!
Transpiration
Plant sweating On wet days, the
cells are swollen with water and they bend, opening the stomata pore
On dry days, they are thin and straight, closing off the stomata pore
But why would it ever close?
Plants lose too much water if they stay open
But they don’t get enough CO2 in if they’re closed….hmmm
So when would be a good time for them to be closed?
How does gas travel in a plant?
Travels through the spongy mesophyll to get to the palisade mesophyll (where photosynthesis occurs)
So what’s the point?
Why do plants need CO2?
Why do they need to get rid of O2?
What happens to the O2?
What else is ‘leafing’ out of the plant besides O2?
Gas Travel
So the respiratory system in animals is for gas exchange….
How does this compare to the plant system?
What do these both need gas for?
A COMPARISON
Explain how the respiratory system in animals is comparable to the gas exchange system in plants.
Make sure you look at structures, functions, importance.
Work as a group.