Unit 1: In and Out
I.RESPIRATION
KC
RC
GC
MYP CONCEPTS
Key concept
Systems
Related
concepts
Global
context
Function,
Interaction
Scientific and
technical
innovation
• Opportunity, risk,
consequences and
responsibility.
Statement of inquiry
The interaction
between processes
and components
impacts the
functioning of a
system.
Cars use petrol as fuel.
It comes to a stop if we
do not put petrol in
the fuel tank.
The petrol provides
the energy that the
car needs to move.
Similarly, all living organisms require
energy if they are to move and carry out the
complex processes of living (this energy is
obtained from food)
THE CONCEPT OF ‘RESPIRATION’ IS
CENTRAL TO ALL LIVING PROCESSES
Respiration is a process which involves a large no. of chemical
reactions that help break down the nutrient molecules such as
glucose in living cells to release energy.
WHAT IS THE DIFFERENCE BETWEEN BREATHING AND RESPIRATION?
•Breathing is only a part of the
respiration process.
•It refers to the intake of air (Taking
in Oxygen) and the letting out of air
(Carbon dioxide) from our body.
7
•One of the energy-producing reactions is
called respiration
•(Respiration is not the same thing as breathing)
•The chemical reactions of respiration take place
in all living cells
•The reaction takes place between oxygen and a
substance which contains carbon. The reaction
produces carbon dioxide and water, and releases
energy
4
plus
an atom of carbon
c
C
a molecule of oxygen
O2
o
o
combine to form a molecule of carbon dioxide
CO2
One example of respiration in ourselves
2.
The lungs absorb oxygen
from the air
2.The stomach and
intestine digest food.
One of the products
is glucose
4
RESPIRATION
Glucose and
oxygen react to
produce energy
for muscle
contraction
1.
15
Air taken in
1.Food
3.The
taken in
blood stream
carries glucose and
oxygen to the
muscles
5 Carbon dioxide
is carried to the lungs
by the blood
8
 The carbon-containing substances come
from FOOD.
 The oxygen comes from the AIR (or
water).
 The energy is used to drive other chemical
reactions taking place in cells.
 One example of this is the release of
energy in muscle cells to make them
contract and produce movement.
An example of an Energy producing
reaction in living organisms:
C6H12O6
sugar
(glucose)
+
6O2
oxygen
6CO2
carbon
dioxide
+
6H2O
water
energy
Energy use in muscle contraction
11
shoulder blade
The blood stream brings
food and oxygen to the
muscle cells. Respiration
occurs in the cells and
releases energy which……
upper arm
bone
lower arm bones
12
…….makes the muscle contract
and pulls the
lower arm up
CAN YOU THINK OF MORE USES OF ENERGY ?
Four Respiration Processes
1) Breathing (ventilation): air in and out of the
lungs.
2) External respiration: gas exchange
between lung and blood
3) Internal respiration: gas exchange
between blood and tissues
4) Cellular respiration: oxygen use to
produce ATP, carbon dioxide as waste
16
Question 1
What is the most important point about
respiration?
(a) it uses oxygen
(b) It produces energy
(c) It produces carbon dioxide
(d) It needs food and air
17
Question 2
In which part of the human body is
respiration most likely to be occurring?
(a) The lungs
(b) The heart
(c) The muscles
(d) All of these
21
Answer
Correct
22
Answer
Incorrect
TASK
• Work in groups of 4 to complete the given
table.
Breathing While at
rest
Number of
breaths
per
minute
After brisk After
walking
running
Answer the following question based on the Task
• Which activity resulted in more number of
breaths per minute? (Resting, brisk walking or
running?)
• Discuss in your groups why do you think the
activity resulted in more number of breaths
per minute ?
Two types of Respiration
• Aerobic
• Anaerobic
Aerobic Respiration:
• Aerobic respiration is a process that requires
oxygen.
• Oxygen helps to break down the food
molecules (glucose) to give rise to carbon
dioxide and water.
• A lot of energy is produced during aerobic
respiration.
• During aerobic respiration only one molecule of
glucose will produce about thirty-eight energy
units.
How is this different from Combustion?
Combustion (burning):
Fuel + Oxygen  Carbon Dioxiode + Water + energy
Aerobic Respiration:
Glucose + Oxygen  Carbon Dioxide + Water + energy
5
The reaction between carbon and
oxygen also releases energy in the
form of heat and light (flames).
Living organisms get their energy from
reactions like this (but not reactions
which are violent enough to produce
flames)
6
CO2
energy release
source of carbon
oxygen
source of
carbon
Anaerobic Respiration
23
• Anaerobic respiration is a term used for the
respiration that occurs without the use of
oxygen.
• It also produces energy but in very less amount
and without oxygen present.
• During Anaerobic respiration one molecule of
glucose will produce only 2 energy units.
Anaerobic respiration in Humans can be
represented by the equation:
• Glucose
Lactic acid + Energy
• Anaerobic respiration happens in humans during
rigorous exercise like push ups, sprinting, weight
lifting etc.
• However it leads to lactic acid accumulation which
results in cramps in the body.
• We therefore breathe in a lot of oxygen to
breakdown the lactic acid (that has been
produced as a result of the anaerobic respiration.)
• Anaerobic respiration in Microorganisms like
yeast and bacteria.
• Glucose →Energy+ Ethanol + Carbon dioxide
32
Black grapes growing in a vineyard
Yeasts are added to crushed grapes to produce wine.
Beer fermenting
Yeasts added to malted barley to produce beer.
34
Dough rising
The yeast is mixed
with the dough
After 1 hour in a warm
place the dough has
risen as a result of the
carbon dioxide
produced by the yeast
36
37
The ‘holes’ in the
bread are made by
the carbon dioxide
bubbles.
This gives the
bread a ‘light’
texture
TASK: Answer the following questions:
1. How is Respiration similar and different from
combustion?
2. Draw a table differentiating between Aerobic and
Anaerobic Respiration.
3. How do humans respire differently from yeasts?
4. Complete the following word equation for Anaerobic
respiration in Yeasts
Glucose
+
+ Energy
AEROBIC AND ANAEROBIC RESPIRATION
Anaerobic respiration
Aerobic respiration



Aerobic
respiration
uses  When a person is doing very fast or powerful
oxygen to oxidise glucose and exercise the blood cannot immediately supply
produce energy.
enough oxygen so another sort of respiration
occurs.
The equation for the oxidation of  This converts glucose into energy without the
glucose is:
need for oxygen and is known as anaerobic
respiration.
C6H12O6 + 6O2 → 6CO2 + 6H2O +
Energy released
The reaction is:
Glucose + Oxygen → Carbon Glucose → Energy released (2units) + Lactic
dioxide + water + (Energy released
acid
38units)
 The lactic acid builds up in the muscles.
Here are a few examples of
High lactic acid concentrations are painful
common types of aerobic 
exercise if a steady pace is and felt as cramp.
maintained.
 Examples of anaerobic exercise are:





Swimming
Cycling
Rowing
Jogging
Cycling
–
–
–
–
Sprinting
Weightlifting
Push ups
Pull ups
THE RESPIRATORY SYSTEM:
Components of the Upper Respiratory
Tract:
Upper respiratory tract function:
• Allows air to enter (and go out) through the nose or mouth.
• The nasal cilia (nose hair) in the nose, acts like a filter keeping
dust and dirt away from the nasal passage. It also moistens
and warms the incoming air.
• The air then passes into the pharynx (A funnel shaped
passageway located right behind the mouth) The pharynx is
part of both the digestive and respiratory system.
• Air then passes into the Larynx (the voice box) where speech
sounds are produced. It is the upper portion of the trachea
and connects the pharynx with the trachea.
• When we eat, a flap -- the epiglottis -- flops down to cover
the Trachea (windpipe) so that food doesn't go down the
windpipe
• .
A clearer view of the epiglottis
• http://www.youtube.com/watch?v=hc1YtXc_8
4A&feature=related
TASK:
• Draw the diagram below and label only the
upper respiratory tract in your note books.
• Read the article (only the 1st page) and write
down the functions of the upper respiratory
tract.
• Click below for article
http://kidshealth.org/parent/general/body_basi
cs/lungs.html#
Components of the Lower
Respiratory Tract
• The Trachea, or windpipe, is a tube that connects
the pharynx and larynx to the lungs, allowing the
passage of air. C- shaped cartilaginous rings around
the trachea protects it and maintains the airway.
• The trachea then divides into the right and left air
tubes - Bronchi (One bronchus). The bronchi allows
the movement of air in and out of the lungs.
• The bronchi then branch out into smaller bronchi
which braches into even smaller tubes called
bronchioles
• The bronchioles end in tiny air sacs called the
alveoli where the exchange of oxygen and
carbon dioxide happens.
TASK:
• Complete labeling the diagram given on slide
46 (Lower respiratory tract) in your notebooks.
• SKIT ON ‘PATH OF OXYGEN’
MECHANICS
OF
BREATHING
Stand up and feel your ribs! Can you feel these
movements when you breathe in and out?
Breathing in = inhalation
•
•
•
•
Diaphragm is lowered
Rib cage is raised
Chest volume increases
Pressure in chest
decreases
• Air enters the lungs to
equalise the pressure
Inhalation
Breathing
Breathing Out = Exhaling
• Diaphragm is raised
• Rib cage is lowered
• Chest volume
decreases
• Pressure in chest
increases
• Air leaves the lungs to
equalise the pressure
Exhalation
Test yourself!!
• Explain how the
diaphragm and the
intercostal muscles work
together to let air into
the lungs
• Write a paragraph using
the words in the box
• 5 minutes
Diaphragm
Contracts
Moves down
Intercostal muscles
Ribs
Up & out
Increases
Decreases
Volume
Pressure
Air
Enter
Test Yourself: Model Answer
• The diaphragm contracts and moves down. At
the same time, the intercostal muscles
contract moving the ribs up and out. This
increases the volume and decreases the
pressure in the lungs. This decrease in
pressure forces air to enter the lung.
• Give yourself a mark out of 5