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