respiration and gas exchange Flashcards
what is respiration
the process of transferring energy from glucose which happens constantly in every living cell
what is the energy transferred by reparation used to make
ATP, stores the energy needed for cell process
aerobic respiration word equation
glucose + oxygen –> carbon dioxide + water
aerobic respiration symbol equation
C6H1206 + 6O2 –> 6CO2 + 6H2O
when does aerobic respiration occur
when there is plenty of oxygen
anaerobic respiration equation
glucose –> lactic acid
when does anaerobic respiration occur
when your body cant supply enough oxygen to your muscles
how efficient is anaerobic respiration
releases much less energy than aerobic, glucose is only partially broken down
what is the problem with lactic acid
builds up in the muscles, gets painful and leads to cramps
anaerobic respiration in plants equation
glucose –> ethanol + carbon dioxide
what indicator is used to show that organisms produce CO2 as they respire
hydrogen-carbonate indicator
hydrogen-carbonate indicator colour change
orange –> yellow in CO2
how do plants exchange gases
diffusion
what is diffusion
the random movement of a substance from a region of high concentration to a region of low concentration
what does the net exchange of gases depend on
light intensity
what happens to gas exchange in plants at night/low light intensity
plants only respire, there is not enough light for photosynthesis
why are leaves broad
large surface area for diffusion
why are leaves thin
gases only have to travel a short distance to reach the cells
why are there air spaces in the leaves
lets gases like CO2 and O2 move easily between cells, increases surface area also
what is the purpose of the stomata
little holes to let gases diffuse in and out, also allow transpiration to occur
what happens to the stomata as it gets dark
it closes, they don’t need to be open to let in CO2 as they can’t photosynthesise
what happens to the stomata when supplies of water from the roots starts to dry up
it closes, stops plant from photosynthesising but if they didn’t close the plant may dry up and die
what is the movement of stomata controlled by
the guard cells, they change their shape and volume
what are the lungs surrounded by
pleural membrane
what muscles run between the ribs
intercostal muscles
what does the trachea split into
2 tubes called bronchi
what do the bronchi split into
bronchioles
where does the gas exchange occur in the lungs
alveoli
where does the gas exchange occur in the lungs
alveoli
what happens to the intercostal muscles when you inhale
contract
what happens to the diaphragm when you inhale
contract
what happens to the thorax volume when you inhale
increases
why is air drawn in when you inhale
the pressure inside the thorax decreases, lower than the pressure out side, forcing air into the lung
what happens to the intercostal muscles when you exhale
relax
what happens to the diaphragm when you exhale
relax
what happens to the thorax volume when you exhale
decreases
why is air forced out when you exhale
the pressure in the thorax is greater than outside, so air is forced out
what do you use to investigate the release of carbon dioxide in your breath
limewater clear –> cloudy
where does blood passing the alveoli come from
the rest of the body, deoxygenated
what happens when deoxygenated blood passes by the alveoli
oxygen diffuses out of the alveoli into the blood, CO2 diffuses out go the blood and into the alveoli
what happens when the newly oxygenated blood reaches body cells
oxygen is released from red blood cells and diffuses into the body cells, CO2 diffuses out of the body cells into the blood where its carried back to the lungs
why are there so many alveoli
the number gives the lungs a huge surface area
why do the alveoli have a moist lining
for gases to dissolve in
why do alveoli have very thin walls
wall are one cell thick, so the gases don’t have far to diffuse
why do the alveoli have a good blood supply
to maintain a high concentration gradient
why are the alveoli walls permeable
so gases can diffuse across easily
how does smoking damage the lungs
damages walls inside alveoli reducing the surface area for gas exchange
what is the effects of tar in cigarettes
damages the cilia in lungs and trachea, when they are damaged they catch less dust and bacteria leading to chest infection
what is the effect of carbon monoxide in cigarettes
reduces the amount go oxygen red blood cells carry, leading to an increase in blood pressure, leading to coronary heart disease
what is the effect of carcinogens in cigarettes
chemicals that lead to cancer
