Gas Exchange
in Animals
Respiration
 All
living things carry out respiration.
Respiration
 All
living things carry out respiration.
 Respiration is the release of energy from
food.
Every cell in your body
performs this complex
cycle!!!
Respiration
 All
living things carry out respiration.
 Respiration is the release of energy from
food.
 This is the process of taking in OXYGEN
Respiration
 All
living things carry out respiration.
 Respiration is the release of energy from
food.
 This is the process of taking in OXYGEN
and giving out CARBON DIOXIDE.
(Opposite with plants…)
Respiration
 All
living things carry out respiration.
 Respiration is the release of energy from
food.
 This is the process of taking in OXYGEN
and giving out CARBON DIOXIDE.
(Opposite with plants…)
 Oxygen has to pass through a MEMBRANE
(like very thin skin which acts as a barrier)
and carried into the cells.
Crossing a Membrane
Respiration





All living things carry out respiration.
Respiration is the release of energy from food.
This is the process of taking in OXYGEN and
giving out CARBON DIOXIDE. (Opposite with
plants…)
Oxygen has to pass through a MEMBRANE
(like very thin skin which acts as a barrier) and
carried into the cells.
In cells, mitochondria (part of the cell) take
the oxygen and release energy. Carbon
dioxide is given out after this.
Part of the cell where
respiration occurs…
Crossing a membrane.
 For
something to cross a membrane, it
must go from HIGH concentration
gradient to LOW concentration gradient.
 http://leavingbio.net/OSMOSIS%20AND%2
0DIFFUSION.htm
Crossing a membrane.
 For
something to cross a membrane, it
must go from HIGH concentration
gradient to LOW concentration gradient.
 EG: there is more oxygen in your lungs
when you breathe in – this oxygen
DIFFUSES across the membrane of your
lung and into your blood stream to be
transported around your body to the rest
of your cells.
So…before we continue…
 Respiration

So…before we continue…
 Respiration
 is the release of energy
from food. (Happens inside your cells!)
So…before we continue…
 Respiration
 is the release of energy
from food.
 Gaseous exchange 
So…before we continue…
 Respiration
 is the release of energy
from food.
 Gaseous exchange  is the movement of
gases across a membrane. (Oxygen from
inside lungs to blood stream!)
So…before we continue…
 Respiration
 is the release of energy
from food.
 Gaseous exchange  is the movement of
gases across a membrane.
 Breathing 
So…before we continue…
 Respiration
 is the release of energy
from food.
 Gaseous exchange  is the movement of
gases across a membrane.
 Breathing  is the PHYSICAL movement
that helps the exchange of gases occur.
(Getting oxygen into our lungs so it can
diffuse into our blood)
So…before we continue…
 Respiration
 is the release of energy
from food.
 Gaseous exchange  is the movement of
gases across a membrane.
 Breathing  is the PHYSICAL movement
that helps the exchange of gases occur.
 DON’T CONFUSE RESPIRATION WITH
BREATHING – IT IS NOT THE SAME THING!
Breathing...
 Refers
to the use of muscles to move
water or air (into lungs or through gills)
Breathing...
 Refers
to the use of muscles to move
water or air (into lungs or through gills).
 This helps respiration efficiency.
Breathing...
 Refers
to the use of muscles to move
water or air (into lungs or through gills).
 This helps respiration efficiency.
 Therefore metabolism can work faster and
there can be a higher level of activity.
Respiratory systems must have…
A
moist surface  gases have to dissolve
in water to pass through a membrane.
Respiratory systems must have…
A
moist surface  gases have to dissolve
in water to pass through a membrane.
 Large surface area  depending on the
size of the animal. This leads to folding
and branching of the surface.
Axolotl…
Respiratory systems must have…
A
moist surface  gases have to dissolve
in water to pass through a membrane.
 Large surface area  depending on the
size of the animal. This leads to folding
and branching of the surface.
 Thin surface  gases can’t diffuse across
thick membranes. These thin membranes
must be protected; think lungs. They are
internal.
Different gas exchange
surfaces
Diffusion across a membrane:
- Protozoa. Organisms so small that all parts
of the cell are close to the water so simple
diffusion across the cell membrane is
enough.
1.
Different gas exchange
surfaces
1.
-
-
Diffusion across a membrane:
Protozoa. Organisms so small that all parts
of the cell are close to the water so simple
diffusion across the cell membrane is
enough.
Jellyfish. Have a central cavity filled with
water and their bodies are only two cells
thick (as above – simple diffusion is
sufficient)
Different gas exchange
surfaces
2. Skin breathers:
- Earthworms. Use skin as respiratory surface.
To keep it moist they secrete a mucus – if
worms dry out, they suffocate.
Different gas exchange
surfaces
2. Skin breathers:
- Earthworms. Use skin as respiratory surface.
To keep it moist they secrete a mucus – if
worms dry out, they suffocate. Earthworms
have a blood system with haemoglobin in a
soluble form to carry the gas to the tissues.