It is about respiration in plants and animals. It is mostly apt for students.

1. RESPIRATION
Done by-:
B.G.S.SNEHA
Class 10

2. BREAK-DOWN OF GLUCOSE BY VARIOUS
PATHWAYS
• First, glucose, a six-carbon molecule breaks down into
pyruvate, a three-carbon molecule. This process takes
place in the cytoplasm.
• There are three different ways by which glucose is oxidized
to provide energy in organisms.
• When this process takes place in absence of oxygen, it is
called anaerobic respiration. Ex-: in yeast.
Ethanol + Carbon dioxide + Energy
(2-carbon molecule)

3. BREAK-DOWN OF GLUCOSE BY
VARIOUS PATHWAYS
• When this process takes place in presence of oxygen , it is
called aerobic respiration. It takes place in mitochondria.
Carbon dioxide + Water + Energy
• Sometimes ,when there is a lack of oxygen in our muscle
cells, another pathway for the break-down of pyruvate is
taken. Here, the pyruvate is converted into lactic acid
which is a three carbon molecule.
Lactic acid + Energy
(3-carbon molecule)
• The build up of lactic acid in our muscle cells during
sudden activity causes cramps.

4. BREAK-DOWN OF GLUCOSE BY
VARIOUS PATHWAYS

5. ATP
• The energy released during cellular respiration is
immediately used to synthesis a molecule called ATP
which is used to fuel all other activities in the cell.
• In these processes, ATP is broken down giving rise to a
fixed amount of energy which can drive the endothermic
reaction taking place in the cell.
• ATP is the energy currency of the cell. The energy released
during the process of respiration is used to make an ATP
molecule from ADP and inorganic phosphate.
• Endothermic processes in the cell then use this ATP to
drive the reactions.
• ATP can be used in the cells for the contraction of muscles,
protein synthesis, conduction of nervous impulses and
many other activities.

6. RATE OF BREATHING IN AQUATIC
ORGANISMS
• Aquatic organisms breathe faster than terrestrial
organisms because the amount of oxygen
dissolved is fairly low compared to the amount of
oxygen in the air.
• Fishes take in water through their mouths and
force it past the gills where the dissolved oxygen is
taken up by blood.

7. HUMAN RESPIRATORY SYSTEM
• In human beings, air is taken into the body
through the nostrils. The air passing through
the nostrils is filtered by fine hairs present in
the passage, called mucus. From here, the air
passes through the throat and then to the
lungs.
• Rings of cartilage present in the throat ensure
that the air passage does not collapse.

8. ALVEOLI
• Within the lungs, the passage divides into smaller and
smaller tubes which finally terminate in balloon-like
structures which are called alveoli.
• The alveoli provide
 a surface where the exchange of gases can take place.
 The walls are richly supplied with blood vessels.
• When we breathe in, air is sucked into the lungs and fills
the expanded alveoli.
• The blood brings CO2 from the rest of the body for release
into the alveoli, and the O2 in the alveolar air is taken up by
blood in the alveolar blood vessels to be transported to all
cells in the body.

9. HAEMOGLOBIN
• When the body size of animals is large, the diffusion
pressure al0ne cannot take care of oxygen delivery to all
parts of the body.
• Instead respiratory pigments take up oxygen from the air
in lungs and carry it to the tissues which are deficient in
oxygen before releasing it.
• In humans, the respiratory pigment is haemoglobin.
• Haemoglobin in present in the red blood cells.
• Carbon dioxide is more soluble in water than oxygen is and
hence it is mostly transported in the dissolved form in our
blood.

10. HUMAN RESPIRATORY SYSTEM