respiration
TRANSCRIPT
RESPIRATIONIN
HUMANS
Lesson Objectives
• Define and state:– Aerobic Respiration– Anaerobic Respiration
• Describe the effect of lactic acid in muscles during exercise
What is Respiration?
Respiration Breathing
Inhaling & Exhaling
???
Digestion & Absorption
Starch
MaltoseGlucose
Absorbed into the blood stream
Respiration
Glucose
ATP
Uptake of glucose into cellsRespiration is the
release of energy from food substances
in living cells
• Muscular Contraction
• Protein Synthesis
• Cell Division
• Transmission of Nerve Impulses
• Heat Generation
What do we use the ENERGY for?
Did You Know That?!
Glucose fuels your brain
Your brain cells need 2X more energy than other cells in the body
Adapted from- The Franklin Institute Online
You consume 106cal/hr sitting
in class
Respiration
Aerobic Respiration
Anaerobic Respiration
What do they mean?
Aerobic Respiration• Word Equation
Glucose OxygenCarbon 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.
Anaerobic Respiration
• 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.
Have you ever wondered...Why do we feel
our muscles ‘burning’ when we exercise too
vigorously Lactic Acid
What’s going on in our body??
At restrest
Oxy
gen
upta
ke
Time(min)
Oxygen uptake
Lactic acid in blood plasma
Normal metabolic rate
Lacti
c ac
id in
bl
ood
plas
ma
0 5 15 20 30 45
What’s going on in our body??
rest exercise
Oxy
gen
upta
ke
Time(min)
Oxygen uptake
Lactic acid in blood plasmaInitial stage of exercise
Normal metabolic rate
Lacti
c ac
id in
bl
ood
plas
ma
0 5 15 20 30 45
What’s going on in our body??
rest exercise
Oxy
gen
upta
ke
Time(min)
Oxygen uptake
Lactic acid in blood plasmaplateau stage
Normal metabolic rate
Lacti
c ac
id in
bl
ood
plas
ma
0 5 15 20 30 45
What’s going on in our body??
rest exercise
Oxy
gen
upta
ke
Time(min)
Oxygen uptake
Lactic acid in blood plasmaplateau stage
Normal metabolic rate
Lacti
c ac
id in
bl
ood
plas
ma
0 5 15 20 30 45
Anaerobic Respiration
What’s going on in our body??
rest exercise recovery
Oxy
gen
upta
ke
Time(min)
Oxygen uptake
Lactic acid in blood plasmaRecovery stage
Normal metabolic rate
Lacti
c ac
id in
bl
ood
plas
ma
0 5 15 20 30 45
Anaerobic Respiration
Why is lactic acid formed during vigorous exercise?
Lactic Acid
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 liver Converted to glucose/ energy
10.3 Experiments to investigate
respiration
• 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
• 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
vacuum flask
pea seedsin antisepticsolution
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
Label the parts that involves in breathing
Human Gas Exchange System
1. Air enters through the nose or the mouth
larynx
pharynx
2. Air moves down the trachea
larynx
pharynx
trachea
3. Air enters the left and right bronchi & into the bronchioles
larynx
pharynx
trachea
bronchi
bronchioles
4. Air enters the alveoli
larynx
pharynx
trachea
bronchi
bronchioles
alveoli
Aaahhh-Choooo!!!!
What is in there?!
Mucus
Imagine life without mucus
Gland Cells & Ciliated CellsGland Cell
Ciliated Cells
4. Air enters the alveoli
larynx
pharynx
tracheabronchi
bronchioles
Alveoli
Alveolus
Adaptation of Alveolus for Gaseous Exchange
CO₂
O₂O₂1 cell thick
alveolar wall
Thin film of moisture
Blood capillary
Oxyhaemoglobin
AlveoliAdaptation 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
10.4 Breathing
Mechanism
Pure
Demonstration
Diaphragm Relaxed
Glass tube (bronchus)
Rubber sheet (diaphragm)
Glass tube (trachea)
Balloons (lungs)
Bell jar (thoracic cavity)
Pure
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
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
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
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
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
(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.
Common Misconception
Pure
4. Air enters the alveoli
larynx
pharynx
tracheabronchi
bronchioles
Alveoli
Alveolus
10.6 How is carbon dioxide transported
around the body?
Pure
• 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
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
What’s Wrong!?Effects of Smoking on the Respiratory System
Effects of Tobacco Smoke
Nicotine
Stimulate adrenaline release
↑ Heartbeat & Blood Pressure
(Your heart works harder)
Makes blood clot easily
↑ Risk of blood clots
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
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
Did You Know That?!
46,000 non-smoking Americans die of heart disease due to 2nd hand smoke!!
Diseases caused by smoking
1. Chronic Bronchitis (Long Term)2. Emphysema3. Lung Cancer
Emphysema•Due to persistent violent coughing
lead to breakdown of alveolar wall
•Experience difficulty in breathing
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
Chronic BronchitisGland Cell
Ciliated Cells
Chronic Bronchitis
Lung Cancer
Apart from lungcancer, cancersof the mouth,throat, pancreaskidneys andurinary bladderare also increased
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