Section 4 - Respiration and Gas Exchange Flashcards
what is respiration
the process of transferring energy from glucose which occurs constantly in every living cell
ATP
The energy transfered by glucose can’t be used directly by cells so it is used to make ATP
ATP stores teh energy needed for many cell proccesses
when a cell needs energy ATP molecules are broken down and energy is released
aerobic respiration word equation
glucose + oxygen -> carbon dioxide + water
aerobic respiration symbol equation
C6H1206 + 6o2 -> 6Co2 + 6H20
aerobic respiration proccess
occurs when there is plenty of oxygen and is the most efficient way to transfer energy from glucose
it produces lots of ATP - around 32 molecules per molecule of glucose
anaerobic respiration proccess
anaerobic respiration is transferring energy from glucose without oxygen. it is highly inefficient, producing less energy ( only 2 ATP molecules per molecule of glucose). The glucose is only partially broken down and lactic acid is also produced. the lactic acid builds up in the muscle which causes cramps and pain
anaerobic respiration in animals equation
glucose -> lactic acid (+energy)
anaerobic respiration in plants equation
glucose -> ethanol + carbon dioxide (+energy)
how do plants get rid of waste products
they diffuse through small holes in the undersides of leaves called stomata
breathing in
1) intercostal muscles and diaphragm contract
2) thorax volume increases
3) this decreases pressure, drawing air in
breathing out
1)intercostal muscles and diaphragm relax
2) thorax volume decreases
3) this increases the pressure and air is forced out
what is the thorax
is the top part of the body, separated by the diaphragm
The lungs in the thorax
they are like pink sponges surrounded by the pleural membranes and protected by the ribcage
The intercostal muscles run between the ribs
where does the air u breath in go
1) trachea
2)bronchus (x2 one into each lung)
3) bronchioles (xmany)
4) alveoli (x many many) where gas exchage occurs
what are alveolis function and how
1) where gas exchange occurs
- the lood passing next to the alveoli has just returnd to the lungs from the rest of the body so it has a lot of CO2 and little 02
- Oxygen diffuses out of alveolus (lohigh concentration) and into blood (low concentration) and vice versa with CO2
- CO2 is breathed out
- when blood reaches body cells oxygen diffuses into them and CO2 into blood
- it is then carried back to lungs and proccess is repeated
how are alveoli specialised
1) huge number of microscopic alveoli gives the lungs an enormous surface area
2) moist lining for gases to diffuse into
3)alveoli has very thin walls (one cell thick) so short diffusion distance
4) great blood supply to maintain high concentration gradient
5) permeable walls for gases to diffuse across easily
how tobacco can affect ur lungs
1) smoking damages walls in alveoli reducing surface area for gas exchange ad leading to diseases such as emphysema
2) the tar in cigarettes damages the cilia (lil hairs) in trachea and lungs. This prevents the cillia from doing their job (catching mucus, dust and bacteria before they get to the lungs and keeping trachea clear by sweeping mucus back to mouth) Chest infections are more likely.
3) Tar irritates the bronchi and bronchioles encouraging mucus production which cant be cleared well by the damaged cilia - causing smokers cough and chronic bronchitis
4) carbon monoxide reduces amount of oxygen blood can carry to make this up heart rate increases which leads to increased blood pressure which damages artery walls making blood clot formation more likely increasing risk of coronary heart disease (eg. heart attacks )
5) tobacco smoke also contains carcinogens - chemicals that can lead to cancer
