Respiration and Gas Exchange - GCSE Flashcards
what do you need to keep your body moving?
energy
where does energy come from and how is it released?
comes from food and is released by respiration
what is respiration?
the process of turning glucose into energy, which happens constantly in every cell
where does energy happen in our body?
in every cell in the body
what is another way of respiration to transfers energy?
by heat (that is why running makes you hot)
what is the energy transferred by respiration used for?
it is used to make a substance called ATP
what does ATP do?
it stores the energy needed for many cell processes
what happens when cells need energy?
ATP molecules are broken down and energy is released
what are the two types of respiration?
aerobic and anaerobic
what is an experiment to show that respiration transfers energy by heat?
(there are 7 steps)
1) soak dried bean in water for a day or two. They will start to germinate (little sprouts will come out of them). Germinating beans will respire
2) boil a similar-sized, second bunch of dried beans. This will kill the beans and make sure they can’t respire. The dead beans will act as your control
3) add each set of beans to a vacuum flask, make sure there’s some air left in the flask (so the beans can respire aerobically)
4) place a thermometer into each flask, seal the top with cotton wool
5) record the temperature of each flask daily for a week
6) repeat the practical, using the same mass of beans each time
7) the beans are well-insulated in the flasks, so when the germinating beans respire, the test flask’s temperature will increase compared to the control flask
what is aerobic respiration?
it is what happens when there is plenty of oxygen available. It is the more efficient way to turn glucose into energy
what does the word aerobic mean?
with oxygen
what does aerobic respiration produce?
it produces lots of ATP, 32 molecules per molecule of glucose
what is the type of respiration you are using most of the time?
aerobic respiration
what is the word equation of aerobic respiration?
glucose + oxygen -> carbon dioxide + water (+ energy)
what is the balanced equation of aerobic respiration?
C6 + H12 + O6 + 6O2 -> 6CO2 + 6H2O
what is anaerobic respiration?
when you do vigorous exercise your body can’t supply enough oxygen to your muscle for aerobic respiration (even though your hear rate increases as much as they can). This type of respiration DOES NOT need oxygen
what does the word anaerobic mean?
without oxygen
which respiration is not the best way to convert glucose into energy?
anaerobic respiration, it releases less energy per glucose molecule than aerobic respiration (just 2 molecules ATP are produced)
what happens in anaerobic respiration?
glucose is only partially broken down and lactic acid is also produced
what happens with lactic acid in anaerobic respiration?
builds up in the muscles, meaning it gets painful and leads to cramps.
what is the word equation of anaerobic respiration?
glucose -> lactic acid (+ energy)
what else other than animals do anaerobic respiration?
plants
how do plants do anaerobic respiration?
they respire without oxygen too, but they produce ethanol and CO2 instead of lactic acid
what is the word equation of anaerobic respiration in plants?
glucose -> ethanol + carbon dioxide (+ energy)
how can you show that living organisms produce CO2 as they respire?
by using a hydrogen-carbonate indicator
when using a hydrogen-carbonate indicator how do you know if there is any presence of carbon dioxide?
when the orange solution changes colour to yellow
how does an experiment of carbon dioxide production by some beans work?
(7 steps)
1) prepare one set of germinating beans and one set of boiled beans (the control)
2) put the same amount of hydrogen-carbonate indicator into two test tubes
3) place a platform made of gauze into each test tube and place the beans on this
4) seal the test tubes with a rubber band
5) leave the apparatus for a set period of time (e.g an hour)
6) during the time the CO2 produced by germinating beans should have an effect on hydrogen-carbonate indicator -> it will have turned yellow
7) the control tube will have stayed the same
what is diffusion?
the movement of particles from places where there are lots of them to places where there are fewer of them
when plants photosynthesise they use the CO2 from where?
the atmosphere
when plants photosynthesise they produce O2 as what?
as a waste product
when plants respire what do they use?
O2 (oxygen)
when plants respire what do they produce as a waste product?
CO2
how are waste products lost in plants?
they are lost through little holes in the underside of leaves called stomata
what does the respiratory system allow you to do?
it lets you breathe in and out
where are the lungs found in?
the thorax
what is the thorax?
the top part of your body
what is the thorax separated by? and from what?
it is separated by a muscle called diaphragm from the lower part of the body
what are the lungs surrounded by?
by the pleural membranes
what are the lungs protected by?
by the ribcage
what muscle runs between the ribs?
the intercostal muscles
the air you breath in goes through where?
the trachea
when air has passed through the trachea, how does it get to the lungs?
through tubes called bronchi (each one is a bronchus), one going to each lung
the bronchi split into progressively smaller tubes called what?
bronchioles
the bronchioles end at where?
small bags called alveoli
what happens in the aveoli?
it is where gas exchange takes place
describe the lungs diagram
handmade flashcard 20
why do you need oxygen in your bloodstream?
to supply your cells for respiration
what do you need to get rid of from your blood?
carbon dioxide
how do you get rid of carbon dioxide?
by breathing in and out
what happens when you breathe in?
5 steps
1) air goes in
2) intercostal muscles pul ribcage and sternum up and out
3) thorax volume increases
4) diaphragm flattens out
5) this decreases pressure, drawing air in
what happens when you breathe out?
1) intercostal muscles and diaphragm relax
2) diaphragm moves up
3) air is forced out
when you exercise what happens to your muscles cells?
they respire more
what do you muscles cells need more and what do they produce when you exercise?
- they need more O2
- they produce more CO2
why does your breathing rate increase when you exercise?
it increases to help deliver more oxygen to cells and to remove the waste CO2
how do you investigate the effect of exercise on breathing rate?
(4 steps)
1) first, sit still for five minutes. Then count for one minute the number of breathes you take
2) now do five minutes exercise and when you stop, directly count your number of breaths for a minute
3) repeat the steps above, and work out the mean (average) results for resting and after exercise
4) could also ask other people to do the same experiment to have even more reliable results
what could be the control variables for the investigations of the effect of exercise on breathing rate?
- time spent on exercise using stopwatch
- temperature of the room using an air conditioning or a thermostat
how do you investigate the release of carbon dioxide in your breath?
(4 steps)
1) set up two boiling tubes as in the diagram on the right. Put the same amount of limewater in each
2) put your mouth around the mouthpiece and breathe in and out several times
3) as you breath in, air from your room is drawn in through boiling tube A. This air contains very little carbon dioxide so the limewater this tube remains colourless
4) when you breathe out, the air you exhale bubbles through the limewater in boiling tube B. This air contains CO2 produced during respiration, so the limewater in this boiling tube turns cloudy
how can you tell carbon dioxide in the exhaled tube air was from respiration?
the lime water remained clear and not cloudy (like it did on the inhaled one)
what carries gas exchange in the body?
alveoli
what is the process of gas exchange?
3 steps
1) blood passing next to the alveoli has just returned to the lungs from the rest of the body, so it contains LOTS of carbon dioxide and very little oxygen. Oxygen diffuses out of the alveolus into the blood. Carbon dioxide diffuses out of the blood into to the alveolus to be breathed out
2) when the blood reaches body cells, oxygen is released from the red blood cells and diffuses into the body cells
3) at the same time, carbon dioxide diffuses out of the body cells into the blood. It is then carried back to the lungs
what gives the lungs an enormous surface are?
the huge number of microscopic alveoli
what is in the alveoli for gases to dissolve in?
moist lining
how thick are alveoli walls and why?
they are one cell thick (very thin walls), so that gases don’t have far to diffuse
why do alveoli need to have a great blood supply?
to maintain high concentration gradient
why are alveoli walls permeable?
so that gases can diffuse across easily
what can smoking severely affect?
your lungs and circulatory
FUMAR MATA - Marcela 2021
how does smoking damage your lungs?
it damages 3 important things
- it damages inside the alveoli, reducing the surface area for gas exchange and leading to diseases like emphysema.
- the tar in cigarettes damages the cilia, which leads to chest infections
- tar also irritates the bronchi and bronchioles, encouraging mucus to be produced which can’t be cleared very well by damaged cilia, causing smoker’s cough and chronic bronchitis
how does the cilia help?
these little hairs along with mucus, catch a load of dust and bacteria before they reach the lungs. The cilia also help keep the trachea clear by sweeping mucus back towards the mouth
what is cilia?
little hairs in your lungs and trachea
what does carbon monoxide in smoke reduce?
the amount of oxygen the blood can carry
what happens when carbon monoxide has reduced the amount of oxygen that the blood can carry?
to make up for the lost oxygen, the heart rate increases which leads to an increase in blood pressure
what does high blood pressure do?
damages the artery walls making the formation of blood clots more likely, this increases the risk of coronary heart disease
what is the effect of the chemical called carcinogens in tobacco?
it causes cancer
