F2 - SEM1 - Living things and air - 7.5 Flashcards
Compare exhaled air and inhaled air
7.5 Gas exchange in animals
- nitrogen, noble gases and other gases: same
- oxygen: more in inhaled air
- carbon dioxide: more in exhaled air
- water vapour: more in exhaled air
- temperature: higher in exhaled air
7.5 Gas exchange in animals
Where does gas exhange take place in humans?
7.5 Gas exchange in animals
At the air sacs
7.5 Gas exchange in animals
True or False?
Exhaled air contains more carbon dioxide than oxygen
7.5 Gas exchange in animals
False
Exhaled air contains 4% carbon dioxide and 16% oxygen
How does Tar affect gas exchange?
7.5 Gas exchange in animals
Tar covers some of the surface of the air sacs =>
Reduce the surface area for gas exchange
7.5 Gas exchange in animals
How does Carbon monoxide affect gas exchange?
7.5 Gas exchange in animals
Carbon monoxide reduces the oxygen-carrying ability of blood
=> less oxygen in the air sacs can enter the blood
7.5 Gas exchange in animals
What chemicals in cigarette reduce the efficiency of gas exchanges?
7.5 Gas exchange in animals
- Tar
- Carbon Monoxide
7.5 Gas exchange in animals
What diseases does smoking cause?
7.5 Gas exchange in animals
- Stroke
- Lung cancer
- Heart disease
7.5 Gas exchange in animals
Other than health problems, how does smoking affect us?
7.5 Gas exchange in animals
- ageing of skin becomes faster
- teeth turn yellow
- fingernails turn yellow
- breath smells bad
- hair and clothes carry a bad smell of cigarette smoke
7.5 Gas exchange in animals
How can we test for the water vapour in exhaled air?
7.5 Gas exchange in animals
Breathe onto a dry mirror
Rub the droplets on the mirror with a piece of dry cobalt chloride paper
The paper changes fro blue to pink in the presence of water.
7.5 Gas exchange in animals
What is the purpose of using soda lime in the experiment?
7.5 Gas exchange in animals
Make sure any carbon dioxide tested is given out during the experiment
7.5 Gas exchange in animals
