INTRODUCTION TO RESPIRATION
Respiration in Fishes
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Respiration
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Respiration
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Concise Notes
INTRODUCTION
Respiration is a fundamental biological
process that enables living organisms to obtain energy from organic
compounds necessary for their survival.
It involves the exchange of gases
particularly oxygen and carbon dioxide, to provide the necessary energy for
cellular activities.
This energy, stored as ATP (Adenosine
Triphosphate), powers essential life functions.
RESPIRATORY ORGANS AND SURFACES
Ø
Body Surface
o
Organisms like earthworms
and amphibians use their moist skin as a respiratory surface.
o
Oxygen diffuses directly
across the skin into the blood stream, while CO2 moves out.
Ø
Gills
o
Found in aquatic organisms such
as fish
o
Consist of thin, filamentous
structure that increases surface area for gas exchange in water
o
As water passes over the gills,
oxygen is absorbed and CO2 is expelled.
Ø
Trachea
o
Present in insects
o
It is a network of tiny tubes
that transport air directly to tissues
o
The trachea system opens to the
outside spiracles, allowing gas exchange without using the circulatory system
Ø
Lungs
o
Found in mammals, birds,
reptiles and some amphibians
o
Lungs are complex, spongy
organs with alveoli (tiny air sacs) that provide a vast surface area for
oxygen and CO2 exchange
Ø
Stomata
o
Found in plant leaves; these
tiny pores open and close to facilitate gas exchange
o
Stomata allows oxygen to enter
for cellular respiration and release carbon dioxide produced during this
process.
Ø
Lenticels
o
These are small pores found in
the bark of woody plants
o
Lenticels help in gaseous
exchange in parts of plants where stomata are absent
Stomata is present in all green plants due to the fact
that they are necessary for photosynthesis.
Lenticels (which are found in only thick regions of
plants) are found only in old stems and roots of plants.
MECHANISM OF GASEOUS EXCHANGE
Ø Inhalation:
Air enters the respiratory tract, oxygen is
absorbed into the blood stream, and CO2 is transported back to the lungs.
Ø Exhalation:
CO2 is released back into the
environment as a waste product of respiration.
Nostril à Voice
Box (larynx) à Pharynx à Trachea
à Bronchi à
Bronchioles à Alveoli (where respiration takes place)
Summary Notes
- Respiration is the breakdown of complex food substances, mainly glucose, to release energy.
- Aerobic and anaerobic respiration are the two types of respiration. Aerobic respiration involves oxygen, while anaerobic respiration involves little or no oxygen.
- Both aerobic and anaerobic respiration start with glycolysis. This is a process that involves the breakdown of glucose into pyruvic acids. The reaction requires two molecules of ATP to start. The reaction produces four molecules of ATP.
- In aerobic respiration, the pyruvic acid is made to go through a series of reaction called the Kreb's Cycle to yield more energy.
- In anaerobic respiration, the pyruvic acid is converted to either ethanol or pyruvic and with release of small amount of energy.