3. ENERGY REQUIREMENT
FOR:
• Muscle contraction
• Active transport
• Transmission of nerves
• Formation of new organelle
• Cell division
• Maintain body temperature
4. Cellular respiration is the
process in which energy-rich
molecules such as glucose are
converted into energy usable for
life processes
5. • The process occurs in gradual
steps that result in the conversion
of the energy stored in glucose to
usable chemical energy in the
form of ATP
• Waste products (CO2 + H2O) are
released through exhaled air,
sweat and urine
8. Aerobic respiration
• Aerobic respiration requires oxygen in
order to generate energy.
• 36 ATP molecules can be made per
glucose
• reactions take place in the mitochondria
10. Chemical equation:
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy
released (2898 kJ/mol)
glucose + oxygen carbon dioxide +
water + E
11. • Activities like sprinting require
levels of energy that are greater
than the body can produce with
the aerobic (with oxygen)
metabolism.
• For these activities, the body
relies on anaerobic (without
oxygen) processes.
Anaerobic respiration
12. • Lactic acid is a byproduct of
anaerobic metabolism.
• It builds up to high levels within
the muscles and eventually leads
to fatigue during these high
intensity activities.
13. Anaerobic respiration
• In the absence of oxygen
• Glucose undergoes a process of
fermentation.
• in the cytoplasm
• In human cells the waste product is
lactic acid.
• 2 ATP are produced during anaerobic
respiration per glucose
15. • Lactic acid will build up causes fatigue
• Fast and deep breathing – supply extra
oxygen to :
– breakdown lactic acid into CO2 and H2O
– Converted back to glycogen
• The amount of O2 needed = oxygen debt
16. Anaerobic in yeast
• In yeast, the waste product is ethanol and
carbon dioxide
• Discuss:
– The important of ethanol and carbon dioxide
production for human
18. Characteristic of
respiratory surfaces
• Large surface area for gas exchange
• Thin respiratory surface, one layer
epithelial cells that allow oxygen and
carbon dioxide to exchange.
• respiratory surfaces must be moist, gases
can only cross cell membranes when they
are dissolved in water or an aqueous
solution
20. Tracheal system
• spiracles - openings on the sides of the thorax
and abdomen
• usually one pair of spiracles per segment
• The tracheae are invaginations of the cuticular
exoskeleton that branch throughout the body
with diameters from only a few micrometers up
to 0.8mm.
• The smallest tubes, tracheoles, penetrate cells
and serve as sites of diffusion for oxygen and
carbon dioxide
28. Fish gills
• The gills of bony fishes are covered by an
operculum. They are four in number with
intervening gill slits
• Branches of the afferent and efferent branchial
arteries pass out to the tip of a gill filament on
each side. A rich capillary network, cross-
connecting these branches and at right angles to
them, occupies each lamella.
• the water flows directly opposite to the flow of
blood in the lamellar capillaries.
29.
30.
31. Amphibian
• Frogs have three respiratory surfaces :
– skin:
• Frogs can breathe through their skin while they are
in wet places.
• They can also exchange gases between the blood
vessels in it, and with its outer environment.
• There are also mucus glands in the skin, these
keep the skin moist.
• Their skin absorbs a lot of dissolved oxygen from
the surrounding atmosphere.
32. – the thin membranes lining its mouth and
pharynx.
– the lungs.
• Adult frogs have poorly developed lungs. Their
lungs are used on dry land while the frogs are
active.
• Gas exchanged by the lungs is used to make the
vocal cords vibrate. They are located in the larynx,
and are necessary for the sound generated by a
frog.
33. • The frog inhales and exahales
– When the frog breathes, the air enters the
mouth. The floor of the mouth drops, and the
external nares open.
– The floor of the mouth rises and falls in a
rhythmic pattern. These movements are
interrupted by a rapid expansion and
contraction of the sides of the body wall at
less frequent intervals.
– At rest, frogs usually breathe through the
lining of the mouth. This process only fills the
lung occasionally.
39. • The lungs are large, lobed, paired
organs
• in the thoracic cavity
• Thin sheets of epithelium (pleura)
separate the inside of the chest
cavity from the outer surface of
the lungs.
• The bottom of the thoracic cavity
is formed by the diaphragm.
41. • Bronchi are reinforced by cartilage ring to
prevent their collapse
• They are lined with ciliated epithelium and
mucus-producing cells.
• Bronchi branch into smaller and smaller
tubes known as bronchioles.
42.
43. • Bronchioles terminate in grape-like sac
clusters known as alveoli.
• Alveoli are surrounded by a network of
thin-walled capillaries.
• Only about 0.2 µm separate the alveoli
from the capillaries due to the extremely
thin walls of both structures.
46. Ventilation
• the mechanics of breathing in and out
• inhalation,
– muscles in the chest wall contract,
– lifting the ribs and pulling them, outward
– diaphragm at this time moves downward
enlarging the chest cavity
• Reduced air pressure in the lungs causes
air to enter the lungs.
47. • Exhalation
– muscles in the chest wall relax,
– lifting the ribs and pulling them, outward
– diaphragm at this time moves downward
enlarging the chest cavity
• Increased air pressure in the lungs causes
air to exit the lungs.
48.
49.
50. • Diffusion is the movement of materials
from a higher to a lower concentration.
• The differences between oxygen and
carbon dioxide concentrations are
measured by partial pressures.
• The greater the difference in partial
pressure the greater the rate of diffusion.
52. Gas exchange
• Partial pressure of oxygen in alveolus is
higher than in alveolar blood capillaries
• Oxygen from the air dissolve in water
[moist] at alveoli lining and diffuse in blood
• Oxygen binds to hemoglobin in red blood
cells to form oxyhaemoglobin.
• Oxyhaemoglobin is carried to all body
cells by blood circulation
54. Carbon dioxide - transported from
the body cells back to the lungs as:
• 1 - bicarbonate (HCO3) - 60%
– formed when CO2 (released by cells making
ATP) combines with H2O
• 2 - carbaminohemoglobin - 30%
– formed when CO2 combines with hemoglobin
(hemoglobin molecules that have given up
their oxygen)
• 3 - dissolved in the plasma - 10%
55. • Carbon dioxide diffuses in the opposite direction,
from capillary blood to alveolar air.
• Partial pressure of carbon dioxide in the blood is
higher than in the alveoli
• Carbon dioxide diffuse out to the alveoli
• Exhalation follows, to get rid of the carbon
dioxide and completing the cycle of respiration.
60. Regulatory mechanism
• After vigorous exercise the rate of
respiration increase and heartbeat
increase
– To supply more oxygen to the muscle
– To eliminate more carbon dioxide from the
muscle
62. • Vigorous exercise = concentration in the blood
CO2 increase
• CO2 dissolve in water forming carbonic acid
• pH blood drop
• Detected by central chemoreceptor in medulla
oblongata
• Nerve impulse send to respiratory centre
• Resp. cen. send impulse to intercostal muscle
and diaphragm
• Ventilation increase
Regulatory mechanism of O2 and CO2
63. CO2
Water
Carbonic acid pH
Central chemoreceptor
[medulla oblongata]
Respiratory centre
Intercostals muscle diaphragm
Ventilation faster CO2 eliminate faster
Detected by
Impulse send
Impulse send
64. Respiration in plant
• Occurs all the time
• In daylight photosynthesis produces plenty
of oxygen
• Used by plant in respiration processes
• At night O2 from atmosphere is used for
respiration
