respiration Flashcards
examples of processes driven by energy from respiration
- anabolic reactions
- active transport
- movement
- mantainance of body temperature
define aerobic respiration
oxidation of glucose in the presence of oxygen with the release of a large amount of energy
word and chemical eqn for aerobic respiration
word eqn:
glucose + oxygen —> large amount of energy + water + carbon dioxide
chemical eqn:
C6H12O6 + 6O2 —> large amount of energy + 6H2O + 6CO2
definition of anaerobic respiration
breakdown of food substances in the absence of oxygen with the release of a relatively small amount of energy
word eqn for anaerobic respiration in humans
glucose —> lactic acid + small amount of energy
word eqn for anaerobic respiration in yeast
glucose —> ethanol + carbon dioxide + small amount of energy
what happens to breathing rate during strenous exercise
- muscles contract vigourously for faster movement, increased energy demand in muscles
- breathing rate and heart rate increases to increase rate of respiration to release more energy
- enables:
- increased rate of oxygenated blood in lungs
- increased rate of transport of oxygen and glucose to muscles
- increased rate of removal of carbon dioxide produced
what if the increase in oxygen uptake by aerobic respiration is unable to meet oxygen demand in muscles
- anaerobic respiration releases the additional energy required for increased muscle contraction
- causes accumulation of lactic acid in muscles that can lead to fatigue.
why does breathing rate and heart rate remain high after exercise?
- some lactic acid is sent to the liver to be oxidised into carbon dioxide and water
- some lactic acid is converted into glucose and later glycogen for storage in liver and muscles.
- addtional oxygen used to oxidise lactic acid is called oxygen debt
- heart and breathing rate return to norm when all lactic acid has been oxidised (oxygen debt is paid)
parts of respiratory system
- trachea
- pharynx
- larynx (voice box)
- diaphragm
- internal intercostal muscles
- external intercostal muscles
- bronchi
- bronchioles
- alveoli
details of larynx (voice box)
- contains vocal chords
details of trachea (windpipe)
- 12 cm long
- supported by C-shaped rings of cartilage, which reinforces front and side of airways, helping to protect it
details of bronchi
- trachea divided into 2 bronchi, one to each lung
epithelium of airways (trachea and bronchi) are lined with what and for what reason?
-
mucus secreting cells
traps dust and bacteria -
ciliated cells
cilia on these cells sweep mucus up to the pharynx to be swallowed
details of bronchioles
- each bronchus divides rapidly into very fine bronchioles
details of alveoli
- clusters of air sacs at the end of bronchioles
- walls of alveoli are respiratory surfaces for gaseous exchange
details of diaphragm
- sheet of muscular tissue attached to the thoracic cavity
- changes volume of thoracic cavity for breathing
process of inhalation
- diaphragm contracts and flattens
- external intercostal muscles contract while internal intercostal muscles relax
- ribs move upward and outward
- volume of thoracic cavity increases
- expansion of lungs cause air pressure inside to decrease
- atmospheric pressure > pressure in lungs
- air rushes into lungs
process of exhalation
- diaphragm relaxes and arches upwards
- external intercostal muscles relax while internal intercostal muscles contract
- ribs move inwards and downwards
- volume of thoracic cavity decreases
- pressure of air in lungs increases
- atmospheric pressure < air pressure inside lungs
- air rushes out of lungs and into atmosphere
structural adaptations of alveoli and how they help
- one-cell thick wall: reduces diffusion distance for faster rate of diffusion of gases
- numerous alveoli: increases surface area to volume ratio for efficient gaseous exchange
- well supplied with capillaries: mantains steep concentration gradient for diffusion
- moisture on suface of inner walls: allows oxygen to dissolve in it
transport of oxygen
- oxygen dissolves in moisture lining alveolar walls
- oxygen diffuses into capillaries
- oxygen binds to haemoglobin in red blood cells to form oxyhaemoglobin
REACTION IS REVERSIBLE depending on amount of oxygen in surroundings.
when blood passes through oxygen-poor tissues, reaction will reverse to be released to tissues
carbon dioxde to hydrogencarbonate reversible reaction
CO2 + H2O ⇌ (catalysed by carbonic anhydrase) H2CO3 ⇌ HCO3 + H
details on carbonic anhydrase
- enzyme found in red blood cells
- catalyses reversible reaction between carbon dioxide and water to form carbonic acid
ways carbon dioxide can be transported
- as hyodrgencarbonate ions in the blood plasma (majority)
- dissolving directly into blood plasma
- binding to haemoglobin to form carbaminohaemoglobin
how carbon dioxide is transported in body
- in the tissues, concentration of carbon dioxide and water is high. carbonic anhydrase catalyses formation of carbonic acid H2CO3 from CO2 and H2O
- carbonic acid dissociates to form hydrogencarbonate ions and hydrogen ions. hydrogencarbonate ions diffuse out of red blood cells and is carried in the plasma.
- in the lungs, hydrogencarbonate ions diffuse back into red blood cells where they are converted into carbonic acid. carbonic anhydrase catalyses conversion of carbonic acid into CO2 and H2O
- CO2 diffuses out of capillary into the alveoli and is expelled during exhalation.
respiratory diseases caused by smoking?
- chronic bronchitis
- emphysema
- lung cancer
causes of respiratory diseases
- smoking
- continual exposure and inhalation of polluted air
symptomps of chronic bronchitis
1.paralysed cilia
2.inflammation of the membrane of trachea and bronchi
3.excessive mucus
4.chronic cough
5.difficulty in breathing (narrowed airways)
6.lungs susceptible to infection
7.may result in emphysema and lung failure
signs and symptoms of emphysema
Developed from chronic bronchitis
- chronic coughing from the chronic bronchitis
- breakdown of the partition walls of the alveoli
- alveoli enlarged and surface area is reduced
- lungs expand and lose elasticity
- great difficulty in breathing leading to strain on the heart
- lung tissue is damaged beyond repair
signs and symtomps of lung cancer
- uncontrolled growth of cells in small area of lungs may spread throughout lungs and block bronchioles
- cancerous growth may eventually spread throughout body
- difficulty breathing
- blood in mucus in lungs