3. Respiration is one of
the important
processes in our
body? So what is
Respiration? What is
anaerobic and aerobic
respiration?
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4. Objectives
◎ Differentiate aerobic from anaerobic
respiration.
◎ Explain the major features and sequence
the chemical events of cellular respiration.
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7. Cellular Respiration
◎ Cellular respiration is a set of metabolic
reactions occurring inside the cells to
convert biochemical energy obtained from
the food (mostly glucose) into a chemical
compound called adenosine triphosphate
(ATP)
◎ The process can be conveniently divided
into two categories based on the usage of
oxygen, namely aerobic and anaerobic
respiration.
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10. Aerobic Respiration
◎ Aerobic respiration is the aerobic
catabolism of nutrients to carbon dioxide,
water, and energy, and involves an electron
transport system in which molecular
oxygen is the final electron acceptor.
The Chemical Equation for Aerobic
Respiration is given below:
Glucose (C6H12O6) + Oxygen 6(O2) → Carbon-
dioxide 6(CO2) + Water 6 (H2O) + Energy (ATP)
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11. Aerobic Respiration
◎ The 2900 kJ of energy is released during
the process of breaking the glucose
molecule and in turn, this energy is used to
produce ATP – Adenosine Triphosphate
molecules which are used by the system for
various purposes.
◎ Aerobic Respiration have 4 different stages:
○ Glycolysis
○ Formation of acetyl coenzyme A
○ Citric Acid Cycle
○ Electron Transport Chain
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13. Aerobic Respiration
Glycolysis
◎ It is the primary step of aerobic
respiration is glycolysis and takes place
within the cytosol of the cell. During the
glycolysis process, the glucose
molecules are splitting and separated
into two ATP and two NADH molecules,
which are later used in the process of
aerobic respiration.
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14. Aerobic Respiration
Formation of Acetyl Coenzyme A
◎ The second step in aerobic respiration is
the formation of acetyl coenzyme A. In this
process, pyruvate is oxidized in the
mitochondria and 2-carbon acetyl group is
produced. The newly produced 2-carbon
acetyl group binds with coenzyme A,
producing acetyl coenzyme A.
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15. Aerobic Respiration
Citric Acid Cycle
◎ The third step in aerobic respiration is the
citric acid cycle, which is also called the
Krebs cycle. In this stage of Aerobic
respiration, the oxaloacetate combines
with the acetyl-coenzyme A and produces
citric acid. The citric acid cycle undergoes a
series of reactions and produces 2
molecules of carbon dioxide, 1 molecule of
ATP, and reduced forms of NADH and
FADH.
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16. Aerobic Respiration
Electron Transport Chain
◎ This is the last step in aerobic respiration.
In this phase, the large amounts of ATP
molecules are produced by transferring the
electrons from NADH and FADH. A single
molecule of glucose creates a total of 34
ATP molecules.
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17. Anaerobic Respiration
◎ Anaerobic respiration is a type of cellular
respiration where respiration takes place in
the absence of oxygen.
◎ The process is also called fermentation
◎ In the absence of oxygen, the glucose
derived from food is broken down into
alcohol and carbon dioxide along with the
production of energy.
Glucose → Alcohol + Carbon dioxide + Energy
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18. Anaerobic Respiration
◎ Anaerobic respiration is also used by multi-
cellular organisms, like us, as a temporary
response to oxygen-less conditions.
◎ Heavy or intensive exercise such as running
demands high energy. Limited supply of
oxygen – body resort to anaerobic respiration
to fulfil the energy demand.
◎ Muscle Cramps? Blame anaerobic respiration.
Partial breakdown of glucose, due to lack of
oxygen, produces lactic acid and the
accumulation of lactic acid causes muscle
cramps. Glucose → Lactic acid + Energy 18
21. Activity 1
By pair, try to make table listing the
differences between Aerobic and
Anaerobic Respiration. Write your answer
in a yellow paper. Rubrics: content 10,
coherence - 10
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23. Difference
◎ The primary difference between aerobic
and anaerobic respiration is the presence
or absence of oxygen during the processes
◎ However, it is a misconception that
humans and other multicellular organisms
use only aerobic respiration. This is
disproven by the fact that our muscles,
during vigorous exercises, undergo
anaerobic respiration, where lactic acid is
produced as the waste byproduct instead
of carbon dioxide.
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Metabolism refers to a set of chemical reactions carried out for maintaining the living state of the cells in an organism. These can be divided into two categories:
Catabolism – the process of breaking molecules to obtain energy.
Anabolism – the process of synthesizing all compounds required by the cells.
Therefore, respiration is a catabolic process, which breaks large molecules into smaller ones, releasing energy to fuel cellular activities
Glycolysis is an anaerobic process
as advised, hot shower after heavy sports relieves the cramps as it improves blood circulation in the body, which in turn enhances the supply of oxygen to the cells.
Anaerobic respiration produces a relatively lesser amount of energy as compared to aerobic respiration, as glucose is not completely broken down in the absence of oxygen.
