Respiration and gas exchange Flashcards
(21 cards)
What can you use to detect CO2?
Hydrogen carbonate indicator
How does Hydrogen Carbonate indicator change?
Orange in normal CO2 concentration
Yellow when CO2 concentration increases
Purple when CO2 concentration decreases
An experiment to demonstrate carbon dioxide production by beans
Put dead beans and germinating beans in tubes, and see that only the germinating beans produce CO2
The germinating beans will also produce more heat
How do plants exchange gasses (CO2 and oxygen)?
Diffusion, different concentration gradients
Why does the net exchange of gases in plants rely on light intensity?
Photosynthesis only happens when there’s light available (day), but plants need to respire day and night to live
So at day they make more oxygen by photosynthesis than they use up in respiration. So at day they release oxygen, as well as taking in more CO2
At night they only respire, so they give out CO2 and take in oxygen
How are leaves adapted for efficient gas exchange?
Broad leaves, higher surface area for diffusion
Thin leaves, decreases time for diffusion of gases
Air spaces in leaf, increases surface area and allows gasses to move easier between cells
Stomata allow gases to diffuse in and out, stop letting water out at night to prevent dehydration, controlled by guard cells
Test to see how light intensity effects CO2 production?
Put leaves which have been exposed to different light intensities with hydrogen carbonate indicator, the more light they are exposed to the less CO2 produced
Structure of the lungs?
P32
What’s the thorax?
Top part of your body, separated by diapraghm
What does the ribcage do?
Protect lungs
What does air we initially breath go through?
Trachea
What does the trachea split into two?
Bronchi
After they are in the lungs, what do the Bronchi split in to?
Bronchioles
What do the Bronchioles split in to?
Alveoli
What happens when you breathe in?
Intercostal muscles and diaphragm contract
Thorax volume increases
Pressure decreased drawing air in
What happens when you breathe out?
Intercostal muscles and diaphragm relax
Thorax volume decreases
Pressure increased forcing air out
What happens the more you exercise?
Breathing rate increases, to take in more oxygen for muscles and remove CO2
What happens at the alveoli?
The oxygen diffuses into the blood, which has a low concentration of CO2 after being to the rest of the body. The CO2 is breathed out
What happens when the blood reaches the body cells?
Oxygen diffuses into cells, CO2 diffuses into blood
How are alveoli adapted for gas exchange?
Lots of microscopic alveoli give it a big surface area
Moist lining for gases to diffuse
Thin walls for diffusion
Good blood supply
Walls are permeable
Problems of smoking tobacco?
Reduces size of alveoli, causing emphysema
Tar damages cilia (Hairs on lungs), causing chest infections
Tar irritates bronchi, causing smokers cough and chronic bronchitis
Contains Carcinogens which lead to cancer
Carbon monoxide, reduces the amount of CO2 blood can hold, increasing heart rate, increasing bood pressure, damaging atery walls, increasing chance of blood clots which lead to Coronary heart disease
