Section 4 - Respiration and Gas Exchange P1 Flashcards
What is respiration?
Respiration is the process of transferring energy from glucose, which happens constantly in every living cell
Can energy produced by respiration be used by cells?
No, so the energy is used to make a substance called ATP
What does ATP do?
ATP stores the energy needed by many cell processes
-when a cell needs energy, ATP molecules are broken down and energy is released
What are the two types of respiration?
aerobic
anaerobic
What is aerobic respiration?
Respiration when there’s plenty of oxygen available
-it’s the most efficient way to transfer energy from glucose
For aerobic respiration how many ATP molecules do you get from one glucose molecule?
32 ATP molecules per molecule of glucose
What is the word equation for aerobic respiration?
glucose + oxygen -> carbon dioxide + water (+ energy)
What is the balanced symbol equation for aerobic respiration?
C₆H₁₂O₆ + 6O₂ -> 6CO₂ + 6H₂O
When you do vigorous exercise and your body can’t supply enough oxygen to your muscles for aerobic respiration, what happens?
Even though your heart and breathing rates increase as much as they can
-your muscles have to start respiring anaerobically as well
For anaerobic respiration how many ATP molecules do you get from one glucose molecule?
2 ATP molecules per molecule of glucose
-much less efficient
What happens during anaerobic respiration?
- the glucose is partially broken down
- lactic acid is produced
- lactic acid builds up in the muscles and gets painful and leads to cramp
What is the word equation for anaerobic respiration in animals?
glucose -> lactic acid (+energy)
What is the word equation for anaerobic respiration in plants?
glucose -> ethanol + carbon dioxide (+energy)
What indicator can be used to show the presence of CO₂?
hydrogen-carbonate indicator
-changes colour from orange to yellow in the presence of carbon dioxide (acidic)
Describe an experiment for how you can prove that respiration releases carbon dioxide:
- soak some dried beans in water, they will start to germinate (will respire)
- boil some another bunch of dried beans, this will kill them (won’t respire) (act as the control)
- put the same amount of hydrogen-carbonate into two test tubes
- place a platform of gauze in each test tube and put the beans on it
- put a bung on the test tubes and leave for an hour
- look at the change in colour of the indicator (germinating beans indicator will be yellow)
Describe an experiment for how you can prove that respiration releases carbon dioxide:
- soak some dried beans in water, they will start to germinate (will respire)
- boil some another bunch of dried beans, this will kill them (won’t respire) (act as the control)
- put the same amount of hydrogen-carbonate into two test tubes
- place a platform of gauze in each test tube and put the beans on it
- put a bung on the test tubes and leave for an hour
- look at the change in colour of the indicator (germinating beans indicator will be yellow)
Describe an experiment for how temperature change produced by respiration can be measured:
- soak some dried beans in water, they will start to germinate (will respire)
- boil some another bunch of dried beans, this will kill them (won’t respire) (act as the control)
- add the beans to a vacuum flask (leave some air in)
- place a thermometer in and seal with cotton wool
- record the temperature of the flasks daily for a week
- repeat
- flask with alive beans will rise in temperature
How are waste products from photosynthesis and respiration released?
Photosynthesis waste product: OXYGEN
Respiration waste product: CARBON DIOXIDE
-released through stomata on the underside of leaves
What is your thorax?
the upper part of your body
What separates the thorax from the lower part of the body?
the diaphragm
What are the lungs surrounded by?
Pleural membranes
-protected by the ribcage (intercostal muscles run between the ribs)
What is the journey which air which you breath in goes on?
- in through the trachea
- down a bronchus (trachea splits into two bronchi)
- down a bronchiole (bronchus splits into bronchioles)
- into an alveoli, where gas exchange takes place
What happens in your thorax when you breath in?
- intercostal muscles and diaphragm contract
- thorax volume increases, this decreases the pressure, drawing air in
What happens in your thorax when you breath out
- intercostal muscles and diaphragm relax
- thorax volume decreases, this increases the pressure, forcing air out
Describe an experiment for how to investigate the effects of exercise on breathing rate:
- sit still for 5 mins,then measure heart rate for 1 min
- do 4 mins of exercise and measure your heart rate again
- repeat and work out the mean results (could try other people to compare results)
Why does exercise increase your breathing rate?
- your muscles respire more
- so they need more oxygen and need more carbon dioxide removed
- so your breathing rate increases
Describe an experiment for how to investigate the effects of respiration on the release of carbon dioxide in your breath:
- set up two boiling tubes with lime water in connected by pipes, and a mouth piece
- breath in and out on the mouth piece several times
- as you breath in tube A has air drawn from the room and therefore the limewater is still clear
- as you breath out tube B turns cloudy as your breath contains carbon dioxide produced in respiration
What gas exchange happens in the alveoli?
- blood passing the alveoli has just returned from the rest of the body so it has lots of carbon dioxide in
- oxygen diffuses out of the alveolus into the red blood cells, carbon dioxide diffuses out of the blood plasma into the alveolus
What gas exchange happens when blood reaches other parts of the body?
- oxygen is released from the red blood cells into the body cells
- carbon dioxide diffuses out of the body cells into the blood, where it is carried back to the lungs
How are alveoli specialised for gas exchange?
- huge number of them(microscopic) - large surface area
- moist lining for gases to dissolve in
- thin walls (one cell thick) - short diffusion distance
- great blood supply - to maintain high concentration gradient
- walls are permeable -gases diffuse easily
What diseases can smoking cause?
- emphysema
- chest infections
- chronic bronchitis
- coronary heart disease
- cancer
How can smoking cause emphysema?
- smoking damages the walls inside the alveoli
- reducing the surface area for gas exchange
How can smoking cause chest infections?
- tar in cigarettes damages cilia
- cilia are essential for catching dust and bacteria in mucus in the trachea
- also sweep mucus back towards the mouth
How can smoking cause chronic bronchitis?
- tar irritates the bronchi and bronchioles
- this encourages mucus to be produced, which can’t be cleared well by the damaged cilia
How can smoking cause coronary heart disease?
- carbon monoxide in cigarette smoke reduces the amount of oxygen the blood can carry
- to make up for this heart rate increases, leading to increased blood pressure
- high blood pressure damages artery walls making blood clots more likely
How can smoking cause cancer?
tabacco smoke also contains carcinogens (chemicals that lead to cancer)
