Respiration and Gas Exchange Flashcards
What is respiration?
the process of releasing energy from glucose, which happens constantly in every cell
When does aerobic respiration occur?
When there’s plenty of oxygen available
When does anaerobic respiration occur in humans?
When you do really vigorous excursive and your body can’t supply enough oxygen for aerobic respiration
What is the equation of aerobic respiration?
Glucose + Oxygen = Carbon Dioxide + Water (+ Energy)
C6H12O6 + 6OO2 = 6CO2 +6H2O (+ Energy)
What is the word equation for anaerobic respiration in humans?
Glucose = Lactic Acid (+ Energy)
Can plants respire without oxygen too?
YES
What do plants produce when they respire anaerobically?
And what is the word equation?
ethanol and carbon dioxide
Glucose = Ethanol + Carbon Dioxide (+ Energy)
How do plants exchange gases?
By diffusion
How are leaves adapted for efficient gas exchange?
They are broad - large surface area for diffusion
They are thin - short distance for gases
There are air spaces inside
Lower surface full of stomata
What are the opening and closing of stomata controlled by?
the cells that surround them (guard cells)
Where are the lungs situated?
In the thorax (top part of body)
What separates the thorax from the rest of the body?
The diaphragm
What are the lungs protected by?
The ribcage
What is the ribcage surrounded by?
the pleural membranes
How does air go into your lungs?
Down the trachea, splits into two bronchi, splits into bronchioles, end at alveoli.
Where does the actual gas exchange take place?
In the alveoli
What happens when you breathe in?
Intercostal muscles and diaphragm contract
Thorax volume increases
This decreases the pressure, drawing air in
What happens when you breathe out?
Intercostal muscles and diaphragm relax
Thorax volume decreases
Air is forced out
How can you investigate the effect of exercise?
On breathing rate
Why does exercise increase breathing rate?
Your muscles respire more during exercise and need to be supplies with more O2 and have more CO2 removed
How many alveoli are there in the lungs?
millions
How are alveoli adapted for sufficient gas exchange?
- They have a large surface area
- Moist lining - for gases to dissolve in
- Thin walls ( one cell thick) - short diffusion distances between air and blood
- Great blood supply - maintain a high conc. gradient
- Walls are permeable
How does smoking lead to emphysema?
Damages walls inside the alveoli, reducing surface area for gas exchange
What does the tar in cigarettes damage?
The cilia in your lungs and trachea
They catch dust and bacteria before they reach the lungs and help keep trachea clear by sweeping mucus back towards the mouth
When cilia are damaged, chest infections are more likely
What does tar irritate?
The bronchi and bronchioles, encouraging mucus to be produced, which can’t be cleared well, causes smokers cough and chronic bronchitis
What does the carbon monoxide in cigarettes cause?
It reduces the amount of oxygen the blood can carry.
to make up for this, heart rate increases - can lead to high blood pressure
high blood pressure damages artery walls, increasing risk of blood clots and coronary heart disease
What in cigarettes, are chemicals that can lead to cancer?
carcinogens
