respiration Flashcards
state 4 processes that are driven by energy released from respiration
- anabolic reactions
- active transport
- movement
- maintenance of body temperature
define aerobic respiration
oxidation of glucose in the presence of oxygen with the release of a large amount of energy
carbon dioxide and water are released as waste products
define anaerobic respiration
oxidation of glucose in the absence of oxygen to form lactic acid / carbon dioxide and ethanol with the release of a relatively small amount of energy
humans -> lactic acid
fungi -> carbon dioxide + ethanol
describe what happens form start to end of vigorous exercise
- faster movement leads to increased and more vigorous muscular contraction, increasing energy demand in muscles
- both breathing and heart rate increases to increase rate of respiration so more energy can be release
- increased breathing and heart rate enables increaed rate of oxygenation of blood at lungs, transport of oxygen and glucose to muscles, andd removal of carbon dioxide produced
- if increased oxygen uptake is unable to meet oxygen demand in muscles, anaerobic respiration occurs
- anaerobic respiration releases the addition energy required for increased muscular contraction
- also causes the accumulation of lactic acid in the muscles and can lead to fatigue
- breathing and heart rate remain high after exercise to supply liver with enough oxygen to oxidise lactic acid into carbon dioxide and water, and also some lactic acid is converted to glucose and later glycogen for storage in liver and muscles
- additional oxygen required to oxidise lactic acid in liver is oxygen debt
- heart rate and breathing rate returns to norm when all lactic acid has been oxidised
how do respirometers work
- soda lime absorbs both carbon dioxide present in test- tube and that produced by living organisms
- when small organisms respire, they take in oxygen and release carbon dioxide, which is absorbed by soda lime
- results in decrease in volume of air in test-tube, hence the colour liquid move toward the living organism
- volume of oxygen used can then be calculated by using the distance moved by colour liquid
state the functions of larynx, bronchus, bronchioles, alveoli, diaphragm
- larynx: contains vocal cords, air passage for sound production
- bronchus: air passage to lungs
- bronchiole: air passage
- alveoli: wall of alveoli form respiratory surfaces for gaseous exchange
- diaphram: changes the volume of thoracic cavity for breathing
describe how trachea is adapted for its function
- lined with cilia: sweeps mucus with trapped dust and bacteria to the pharynx and swallowed into oesophagus to be removed
- lined with goblet cells: mucus secreted by goblet cells trap dust and bacteria in the air and are swept to pharynx and swallowed into oesophagus to be removed
- supported by C-shaped rings of cartillage: reinforces the front and sides of trachea to protect and maintain the airway
describe the breathing mechanism (inhalation + exhation)
Inhalation / Exhalation
1. Diaphragm contracts and flattens / relaxes and arches upward
2. External intercostal muscles contract / relax while internal intercostal muscles relax / contract
3. Ribs move upward and outward / downward and inward
4. Volume of thoracic cavity increases / decreases
5. Expansion / Compression in lungs causes air pressure inside lungs to decrease / increase
6. Atmospheric pressure is higher / lower than air pressure inside lungs
7. Air rushes in / is forced out of the lungs
contrast the composition of inhaled and exhaled air
Inhaled vs Exhaled
* Oxygen: 21% vs 16% (decrease)
* Carbon dioxide: 0.03% vs 4% (increase)
* Nitrogen: 78% vs 78% (no change!!!)
* Water: variable vs saturated (increase)
* temperature: variable vs body temperature (usually increase)
describe how alveoli are adapted for their function
- walls are one-cell thick: reduce diffusion distance for more efficient diffusion of gases through it
- numerous alveoli in lungs: increase SA:V for more efficient diffusion of gases through it
- well supplied with capillaries: to maintain a steep concentration gradient for diffusion
- interior is lined with thin film of moisture: allow oxygen to dissolve in it
explain how oxygen and carbon dioxide conc. gradients are maintained between alveolar air and blood
- continuous blood flow through capillaries
- breathing air in and out of alveoli
outline how oxygen is transported in the blood
- oxygen dissolves in the moisture lining the alveolar walls annd diffuse into blood capillaries
- oxygen combines with haemoglobin in RBCs to form oxyhaemoglobin
- since this reaction is reversible depending on amount of oxygen in surroundings, when blood passes through oxygen-poor tissues, the reaction will reverse and release oxygen to the tissues
state 3 ways carbon dioxide is transported, and identify the main way
- in the form of hydrogen carbonate ions in blood plasma (majority)
- by dissolving directly in blood plasma
- by binding to haemoglobin in RBCs to form carbaminohaemoglobin
outline how carbon dioxide is transported by hydrogen carbonate ions
- At tissues, concentration of water and carbon dioxide is high. carbonic anhydrase catalyses the formation of carbonic acid from water and carbon dioxide
- Carbonic acid will dissociate to form hydrogencarbonate ions and hydrogen ions, without needing carbonic anhydrase. The hydrogencarbonate ions diffuse out of RBCs and is carried in blood plasma
- In the lungs, hydrogencarbonate ions diffuse back into RBCs where they are converted back into carbonic acid. Carbonic anhydrase catalyses the conversion of carbonic acid into water and carbon dioxide
- The carbon dioxide diffuses out of blood capillaries into alveoli and is expelled during exhalation
identify 3 respiratory diseases and state their causes
- Chronic Bronchitis: smoking, continual inhalation of polluted air
- Emphysema: smoking, continual exposure and inhalation of polluted air, developed from chronic bronchitis
- Lung cancer: smoking, continual expose and inhalation of smoke and polluted air
