respiration Flashcards
respiration definition
the breakdown of food molecules to release the stored chemical energy they contain
what are the two types of respiration
anaerobic
aerobic
aerobic respiration:
uses oxygen
happens in the cells of animals, plants and many other organisms
happens in the mitochondria
word equation for aerobic respiration
glucose + oxygen -> carbon dioxide + water
symbol equation for aerobic respiration
6O2 + C6H12O6 -> 6CO2 + 6H2O
what form is energy released in from aerobic respiration
ATP
ATP:
used to pass energy from respiration to other processes that need it
present in all living cells
transfers energy between the process that releases it (respiration) and the process in the cell that uses it up
what is anaerobic respiration
respiration without oxygen
anaerobic respiration:
glucose is not completely broken down and less energy is released
can occur when oxygen is in short supply - advantage
occurs mainly after exercise or at high altitudes
causes muscle cramps due to a buildup of lactic acid in the blood stream
need to oxidise lactic acid by using more oxygen - the volume of oxygen needed is called the oxygen debt
word equation for anaerobic respiration in humans/animals
glucose -> lactic acid (+some ATP)
word equation for anaerobic respiration in yeast/plants
glucose -> ethanol + carbon dioxide (+some ATP)
practical: effect of temperature in respiration in yeast
independent - temperature
dependent - number of bubbles/rate of respiration
control - time count bubbles for two mins, volume of yeast and sugar
1) make 4 water baths of different temps
2) get 4 boiling tubes and fill each one with 10ml of the yeast and sugar solution
3) place one boiling tube in each water bath for 2 mins
4) after 2 mins start counting number of bubbles released in one min
you put them in the water baths for 2 mins before you start counting bubbles to allow the yeast to acclimatise to the temp
disadvantages:
- could miscount
- temp was not controlled
- volume not measured carefully
- not all yeast was acclimatised
gas exchange definition
process of absorbing inhaled atmospheric oxygen molecules into the blood stream and offloading carbon dioxide from the bloodstream to the atmosphere
define breathing
the process of taking air in and out of the lungs
define respiration
a chemical reaction that happens in all living cells, where energy is released from glucose so that all other chemical processes need for life can happen
what happens in gas exchange
the oxygen diffuses from the alveoli into the red blood cells and binds with haemoglobin to form oxyhaemoglobin
the carbon dioxide diffuses from the plasma of the capillaries into the alveolars is breathed out
alveoli adaptations
- large surface area -> many small alveoli rather than one large alveolus
- short distance for diffusion -> alveoli and capillary walls each one cell thick
- high concentration gradient -> many capillaries/rich blood supply -> carries oxygen away from the exchange surface
- moist -> gases can diffuse more readily
what do the trachea, bronchi and bronchioles do
transport air to and from the alveoli
trachea:
- cartilage in ‘C’ shape
- open end oesophagus to allow food to move through via peristalsis
- trachea subdivides into smaller airway passes - right and left main bronchus
bronchi:
- cartilage forms complete circular rings
- branches off further into bronchioles
lining of trachea and bronchi:
goblet cells - secrete mucus, this traps particles of dirt and bacteria
ciliated cells - covered in tiny hair-like structures (cilia). these beat forwards and backwards, sweeping the mucus and trapped particles out towards the mouth
dirt and bacteria are prevented from entering the lungs where they might cause an infection
how do the cilia prevent lung infections
they trap the pathogens in the mucus and sweep away from the lungs
alveoli:
- this is where gas exchange in the blood occurs
- oxygen diffuses into the blood from the alveoli
- carbon dioxide diffuses out of the blood into the alveoli
pleural cavity:
pleural membrane - separates the thorax from the lungs. it makes up a continuous envelope around the lungs, creating an airtight seal
pleural fluid - lubricates the surface of the lungs, so it doesn’t stick to the inside of the chest
function of the ribs
protect the lungs
intercostal muscles:
- found in between each rib
- help control the movement of air in and out of the lungs
diaphragm:
- dome shaped muscle separating the contents of the thorax form the abdomen
- helps to control the movement of air in and out of the lungs for ventilation
ventilation definition
moving air in and out of the lungs
- requires a difference in air pressure
- air moves from high to low pressure
external intercostal muscles when inhaling
- external contract
- internal relax
external intercostal muscles when exhaling
- external relax
- internal contract
ribs when inhaling
up and out
ribs when exhaling
in and down
diaphragm when inhaling
contracts (flatter shape)
diaphragm when exhaling
relaxes into a dome shape
chest when inhaling
volume increases
chest when exhaling
volume decreases
air pressure when inhaling
inside thorax lower
air pressure when exhaling
inside thorax higher
air movement when inhaling
moving in
air movement when exhaling
moving out
tidal volume definition
volume of air inhaled and exhaled with each breath
oxygen debt definition
amount of extra oxygen required by muscle tissue to oxidise lactic acid and replenish depleted ATP after vigorous exercise
vital capacity definition
amount of air that can be forcibly expelled form the lungs after breathing as deeply as possible
why does your breathing rate increase during exercise
- your muscles are CONTRACTING MORE
- so they need MORE ENERGY
- so they need to do MORE RESPIRATION
- so they need MORE OXYGEN
- so the breathing rate has to increase
immediate effects of exercise:
- increased breathing rate
- increase in tidal volume (amount of air breathing in or out of the lungs in one breath)
long term effects of regular exercise
- stronger diaphragm and intercostal muscles
- increased number of alveoli
- increase in vital capacity
- increased rate of gaseous exchange
- more oxygen delivered
- more efficient removal of carbon dioxide
examples of aerobic exercise
- swimming
- jogging
- cycling
examples of anaerobic exercise
- sprinting
- ice hockey
- weight lifting
practical: how intensity of exercise affects breathing rate
independent - intensity of exercise
dependant - breathing rate
controls - type of exercise, person, climate/temperature/humidity
uncontrolled - previous exercise, injury/illness, what eaten that day
C - change intensity of exercise, do 3 different intensities
O - use the same person (same age, sex, average exercise level)
R - repeat 3x and find average
M - measure breathing rate by holding hand on back and counting
S - keep the amount of time to rest between each exercise the same
S - same temperature of room
as you increase exercise intensity, the breathing rate increases as well
effects of smoking: effects of carbon monoxide
- carbon monoxide binds to haemoglobin
- carbon monoxide + haemoglobin -> carboxyhaemoglobin
- irreversible reaction -> impossible to form oxyhaemoglobin -> oxygen can’t be carried to respiring cells
effects of smoking: effects of tar
- tar paralyses cilia -> cilia can’t get ride of excess mucus -> further irritation
- settles in the alveoli and reduce the surface area available for gas exchange
effects of smoking: lung cancer
carcinogens -> chemicals that increase risk of cancers (results in mutations) -> causes tumours -> blockages
- smoking deposits tar into the lungs
- tar is a carcinogen and increases the risk of cancers
- in lung cancer a growth develops in the wall of bronchial tube
- this can cause a blockage
- unless the growth is discovered and destroyed, the cancer can spread
effects of smoking: cilia
- cilia get coated in tar, becoming paralysed-> can’t remove mucus with trapped pathogens -> increased risk of infections
effects of smoking: bronchitis
- the excess mucus collecting in the bronchi and bronchioles as a result of the destruction of the cilia means that irritants freely enter the lungs
- this leads to inflammation called bronchitis
effects of smoking: emphysema
- the walls of the alveoli become thin and weak
- coughing results in the bursting of some of the weaken alveoli and in the long term this reduces the lungs surface area available for oxygen absorption
- also reduces the elasticity of the lung tissue so that breathing is painful and difficult
nicotine:
- nicotine is the addicting part of the cigarette -> has effects on the nervous system
- releases adrenaline-. increased chance of heart attack
