9. • Word Equation
Glucose Oxygen
Carbon
Dioxide Water
Large
amount
of Energy
Definition:
Complete oxidation (breakdown) of food substances
that occur in the presence of oxygen, with the release
of large amount of energy.
Carbon dioxide and water produced as waste products.
10. • Word Equation (In human muscle cells)
Glucose Small amount
of Energy
Lactic
Acid
Definition:
Incomplete breakdown (oxidation) of food substances
that occur in the absence of oxygen, with the release
of small amount of energy
Lactic acid produced as waste products.
11. Have you ever wondered...
Why do we feel
our muscles
‘burning’ when
we exercise too
vigorously
19. Vigorous muscular contraction
Muscles need to respire more
to release more energy
(Glucose + O2 CO2 +
H20 + ↑Energy)
More glucose and oxygen
needed for respiration
Heart pumps faster to
circulate blood around
the body at a faster rate
Increase build-up of CO2
Panting to remove carbon dioxide
& take in oxygen at a faster rate
Insufficient oxygen to meet the
vigorous muscular contraction
Anaerobic respiration occurs in
muscles cells, and lactic acid is
produced
During recovery, lactic acid is
transported to the liverConverted to glucose/ energy
21. • The potassium hydroxide in flask A removes carbon
dioxide from the air entering flask B.
• The limewater in flask B should not turn chalky.
• The air entering flask C does not contain carbon dioxide.
Hence, any carbon dioxide detected in flask D would be
due to respiration by the snails.
Carbon dioxide is a product of respiration
potassium
hydroxide solution
limewater limewatersnails
A B C D
Studying Respiration10.3
22. • The glucose solution that is used was
first boiled and cooled prior to addition
of the yeast cells. Boiling removed the
dissolved oxygen from the solution.
• Due to the limited oxygen available to
the yeast, the yeast undergoes
anaerobic respiration.
• If carbon dioxide is released during the
anaerobic respiration of yeast, the
limewater will turn chalky. limewaterglucose and yeast
suspension
Carbon dioxide is a product of respiration
Studying Respiration10.3
23. vacuum
flask
pea seeds
in antiseptic
solution
thermometer
cotton wool
plug
• The vacuum flask prevents heat from
escaping and entering the area where
the seeds are germinating.
• The cotton wool plug allows gaseous
exchange between the seeds and the
environment.
• The antiseptic solution prevents the
growth of microorganisms like bacteria.
• If heat is produced during respiration,
the thermometer would register a
temperature higher than the surrounding
temperature.
Heat is a product of respiration
Studying Respiration10.3
34. 4. Air enters the alveoli
larynx
pharynx
trachea
bronchi
bronchioles
Alveoli
Alveolus
35. Adaptation of Alveolus for Gaseous
Exchange
CO₂
O₂O₂
1 cell thick
alveolar wall
Thin film of
moisture
Blood
capillary
Oxyhaemoglobin
36. Alveoli
Adaptation of Alveoli: Functions:
a) Numerous alveoli To provide a very large surface area for
gas exchange
a) One-cell thick wall
of blood capillary
and alveolar wall
To allow for rapid diffusion of gases
a) A film of moisture
on inner alveolar
surface
To allow for oxygen to dissolve in it
a) Densely
surrounded by
blood capillaries
To maintain a steep concentration gradient
for continuous flow of gases through
diffusion between blood and alveoli
39. What happens when the rubber sheet is pulled down?
Predict the observations:
• Volume of space in bell jar
increases.
• Air pressure in bell jar
decreases.
• Atmospheric pressure is now
higher than the air pressure
inside.
• Air is forced into the balloons
through the tube.
10.4
Pure
40. Volume of thorax increases:
• Pressure in thorax drops
•Atmospheric pressure (outside) > Thorax Pressure (inside)
External Intercostal
Muscles Contract
Internal Intercostal
Muscles Relax
Ribs swing upwards and outwards
Diaphragm contracts, pulling it down into a flattened shape
Air is forced into the lung.
Inspiration/Inhalation10.4
Pure
41. Volume of thorax decreases:
• Pressure in thorax __________.
•Atmospheric pressure (outside) < Thorax Pressure (inside)
External Intercostal
Muscles _________.
Internal Intercostal
Muscles __________.
Ribs returns to original positions.
Diaphragm _________ and moves __________.
Air is forced ______ of the lung.
Expiration/ Exhalation
relax contract
relaxed upwards
increases
out
10.4
Pure
42. Inspiration
Component of inspired air
• 21% oxygen
• 0.03 % carbon dioxide
• 1% other gases
• 78% nitrogen
• Variable (water vapour
and dust)
• Lower temperature
10.4
Pure
43. Expiration
Component of expired air
• 16% oxygen
• 4% carbon dioxide
• 1% other gases
• 78% nitrogen
• Saturated water vapour.
• Higher temperature.
• No dust particle / little
10.4
Pure
44. (1) During inhalation, the air that enters the lungs
causes the lung to expand.
* During inhalation, the volume of the
thoracic cavity increases, resulting in
a drop in pressure.
The higher atmospheric air pressure
causes air to rush in.
Pure
45. 4. Air enters the alveoli
larynx
pharynx
trachea
bronchi
bronchioles
Alveoli
Alveolus
47. • As the tissues undergo aerobic
respiration, carbon dioxide produced
diffuse into the blood and enters into
the red blood cells.
• In the red blood cell, enzyme
carbonic anhydrase are present to
catalyse carbon dioxide and water
to form carbonic acid.
• Carbonic acid is then converted into
hydrogencarbonate ions, HCO3
-,
which then diffuses out of the red
blood cells.
• Most of the carbon dioxide is
transported as hydrogencarbonate
ions in the blood plasma.
10.6
Pure
48. In the lung, hydrogencarbonate ions ,HCO3
-
diffuse back into the red blood cell, where they are
converted back into carbonic acid, and then carbon
dioxide and water by enzyme carbonic anhydrase.
Carbon dioxide diffuses out of blood capillaries into
the alveoli, and is expelled out when you breathe
out.
10.6
Pure
51. Effects of Tobacco Smoke
Nicotine
Stimulate
adrenaline release
↑ Heartbeat &
Blood Pressure
(Your heart works
harder)
Makes blood clot
easily
↑ Risk of blood
clots
52. Effects of Tobacco Smoke
Carbon
Monoxide
Combines with
Haemoglobin
(Irreversibly)
Forms
carboxyhaemoglobin,
↓ O₂ Transport
↑ rate of fatty
deposit in inner
arterial wall
↑ Risk of coronary
heart disease
53. Effects of Tobacco Smoke
Tar
Carcinogenic
(Cancer causing)
↑ risk of lung cancer
Paralyses cilia of air
passages
Blockage in air sacs
and ↓ gas exchange
efficiency
54. Did You Know That?!
46,000 non-smoking Americans die of
heart disease due to 2nd hand smoke!!
55. Diseases caused by smoking
1. Chronic Bronchitis (Long Term)
2. Emphysema
3. Lung Cancer
56. Emphysema
•Due to persistent violent coughing
lead to breakdown of alveolar wall
•Experience difficulty in breathing
57. Chronic Bronchitis
• Particles in tobacco smoke can cause chronic
bronchitis
– Excessive mucus secreted to trap particles
– But, paralysed cilia cannot function normally
– Airway become blocked
