Page 129 - Knowledge Organiser Yr8 24-25

Knowledge Base: Science 8.3 Breathing and Respiration Year 8
1. Aerobic Respiration
1.1
List three things your body needs energy for
Movement, growth, keeping warm.
1.2
What is respiration?
A chemical reaction that occurs in cells to release energy.
1.3
Give the word equation for aerobic respiration
glucose + oxygen → water + carbon dioxide
1.4
Where in cells does aerobic respiration occur?
In the mitochondria.
1.5
Where does the glucose needed for aerobic respiration come from?
Our food.
1.6
Where does the oxygen needed for aerobic respiration come from?
Oxygen entering our lungs when we breathe in.
1.7
How does the glucose and the oxygen travel round our body to get to every cell?
In our blood.
1.8
Carbon dioxide is a toxic waste product of respiration. How do we get it out of our bodies?
Travels in our blood to our lungs where it is expelled when we breathe out.
2. Respiratory System
2.2
What is the purpose of cartilage in the trachea?
To hold the trachea open and stop it collapsing.
2.3
What does the trachea split into?
Bronchi (which lead into each lung).
2.4
What do the bronchi split into?
Thousands of smaller tubes called bronchioles.
2.5 What is found at the end of each bronchiole? Microscopic air sacs called alveoli.
2.6
What is the function of the diaphragm?
Muscle that moves up and down to move air in and out of the lungs.
3. Gas Exchange
3.1
Which gas diffuses into the blood from the alveoli in the lungs?
Oxygen.
3.2
Which gas diffuses out of the blood into the alveoli in the lungs?
Carbon Dioxide.
3.3
What do we mean by gas exchange in the lungs?
Oxygen diffusing into the blood and carbon dioxide diffusing out of the blood.
3.4
Where in the lungs does gas exchange take place?
In the alveoli.
3.5
What are the three features of the alveoli which makes them good at exchanging gasses?
1. They create a large surface area.
2. They have thin walls that are one cell thick. 3. They have a good blood supply.
2. Respiratory System
2.1
Label the structures of the respiratory system.
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