Section 4 - Respiration and Gas Exchange

Question 1

what is respiration

Answer 1

the process of transferring energy from glucose which occurs constantly in every living cell

Question 2

ATP

Answer 2

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

Question 3

aerobic respiration word equation

Answer 3

glucose + oxygen -> carbon dioxide + water

Question 4

aerobic respiration symbol equation

Answer 4

C6H1206 + 6o2 -> 6Co2 + 6H20

Question 5

aerobic respiration proccess

Answer 5

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

Question 6

anaerobic respiration proccess

Answer 6

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

Question 7

anaerobic respiration in animals equation

Answer 7

glucose -> lactic acid (+energy)

Question 8

anaerobic respiration in plants equation

Answer 8

glucose -> ethanol + carbon dioxide (+energy)

Question 9

how do plants get rid of waste products

Answer 9

they diffuse through small holes in the undersides of leaves called stomata

Question 10

breathing in

Answer 10

1) intercostal muscles and diaphragm contract
2) thorax volume increases
3) this decreases pressure, drawing air in

Question 11

breathing out

Answer 11

1)intercostal muscles and diaphragm relax
2) thorax volume decreases
3) this increases the pressure and air is forced out

Question 12

what is the thorax

Answer 12

is the top part of the body, separated by the diaphragm

Question 13

The lungs in the thorax

Answer 13

they are like pink sponges surrounded by the pleural membranes and protected by the ribcage
The intercostal muscles run between the ribs

Question 14

where does the air u breath in go

Answer 14

1) trachea
2)bronchus (x2 one into each lung)
3) bronchioles (xmany)
4) alveoli (x many many) where gas exchage occurs

Question 15

what are alveolis function and how

Answer 15

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

Question 16

how are alveoli specialised

Answer 16

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

Question 17

how tobacco can affect ur lungs

Answer 17

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