Cellular respiration and photosynthesis are opposing but complementary processes. Cellular respiration occurs in most living organisms and involves the breakdown of glucose and release of carbon dioxide and energy. Photosynthesis exclusively occurs in plants, algae and some bacteria and requires carbon dioxide, water and sunlight to produce glucose and oxygen. Both processes are essential for life - cellular respiration provides energy for organisms while photosynthesis produces the oxygen and glucose needed for respiration.

1. Hasimah Azit

2. Respiration Overview
EXTERNAL
INTERNAL
TRANSPORTATION

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

6. Cellular respiration
Substrate for energy production:
Glucose – obtain from food
Oxygen - from air

7. – Aerobic respiration
– Anaerobic respiration

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

9. 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

14. Chemical reaction for
Anaerobic in muscle
C6H12O6 → 2C3H6O3 + E (150kJ mol−1)
[Glucose] [lactic acid] + Energy

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

17. Comparison
Between aerobic and anaerobic
respiration:
–Place
–Reaction
–Product
–Energy produced

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

19. Insect respiratory structure

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

25. Fish respiratory structure

26. gills

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.

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.

36. Human respiratory structure

37. General structure of
human respiratory system

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.

40. Lung

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.

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.

44. alveolus

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.

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.

51. Gas exchange alveolus

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

53. From cell to blood

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.

56. From blood to alveolus

59. What are differences between
inhaled and exhaled air?

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

61. Resting stage
• Breathing rate = 16 – 18 breaths/minute
• Heartbeat rate = 60 – 80 beats/minute
After activities
• Breathing rate = 30 – 40 breaths/minute
• Heartbeat rate = 120 – 150 beats/minute

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

65. Compare respiration and
photosynthesis