Section 4 - Respiration and Gas Exchange P1

Question 1

What is respiration?

Answer 1

Respiration is the process of transferring energy from glucose, which happens constantly in every living cell

Question 2

Can energy produced by respiration be used by cells?

Answer 2

No, so the energy is used to make a substance called ATP

Question 3

What does ATP do?

Answer 3

ATP stores the energy needed by many cell processes

-when a cell needs energy, ATP molecules are broken down and energy is released

Question 4

What are the two types of respiration?

Answer 4

aerobic

anaerobic

Question 5

What is aerobic respiration?

Answer 5

Respiration when there’s plenty of oxygen available

-it’s the most efficient way to transfer energy from glucose

Question 6

For aerobic respiration how many ATP molecules do you get from one glucose molecule?

Answer 6

32 ATP molecules per molecule of glucose

Question 7

What is the word equation for aerobic respiration?

Answer 7

glucose + oxygen -> carbon dioxide + water (+ energy)

Question 8

What is the balanced symbol equation for aerobic respiration?

Answer 8

C₆H₁₂O₆ + 6O₂ -> 6CO₂ + 6H₂O

Question 9

When you do vigorous exercise and your body can’t supply enough oxygen to your muscles for aerobic respiration, what happens?

Answer 9

Even though your heart and breathing rates increase as much as they can
-your muscles have to start respiring anaerobically as well

Question 10

For anaerobic respiration how many ATP molecules do you get from one glucose molecule?

Answer 10

2 ATP molecules per molecule of glucose

-much less efficient

Question 11

What happens during anaerobic respiration?

Answer 11

• the glucose is partially broken down
• lactic acid is produced
• lactic acid builds up in the muscles and gets painful and leads to cramp

Question 12

What is the word equation for anaerobic respiration in animals?

Answer 12

glucose -> lactic acid (+energy)

Question 13

What is the word equation for anaerobic respiration in plants?

Answer 13

glucose -> ethanol + carbon dioxide (+energy)

Question 14

What indicator can be used to show the presence of CO₂?

Answer 14

hydrogen-carbonate indicator

-changes colour from orange to yellow in the presence of carbon dioxide (acidic)

Question 15

Describe an experiment for how you can prove that respiration releases carbon dioxide:

Answer 15

• soak some dried beans in water, they will start to germinate (will respire)
• boil some another bunch of dried beans, this will kill them (won’t respire) (act as the control)
• put the same amount of hydrogen-carbonate into two test tubes
• place a platform of gauze in each test tube and put the beans on it
• put a bung on the test tubes and leave for an hour
• look at the change in colour of the indicator (germinating beans indicator will be yellow)

Question 16

Describe an experiment for how you can prove that respiration releases carbon dioxide:

Answer 16

• soak some dried beans in water, they will start to germinate (will respire)
• boil some another bunch of dried beans, this will kill them (won’t respire) (act as the control)
• put the same amount of hydrogen-carbonate into two test tubes
• place a platform of gauze in each test tube and put the beans on it
• put a bung on the test tubes and leave for an hour
• look at the change in colour of the indicator (germinating beans indicator will be yellow)

Question 17

Describe an experiment for how temperature change produced by respiration can be measured:

Answer 17

• soak some dried beans in water, they will start to germinate (will respire)
• boil some another bunch of dried beans, this will kill them (won’t respire) (act as the control)
• add the beans to a vacuum flask (leave some air in)
• place a thermometer in and seal with cotton wool
• record the temperature of the flasks daily for a week
• repeat
• flask with alive beans will rise in temperature

Question 18

How are waste products from photosynthesis and respiration released?

Answer 18

Photosynthesis waste product: OXYGEN
Respiration waste product: CARBON DIOXIDE
-released through stomata on the underside of leaves

Question 19

What is your thorax?

Answer 19

the upper part of your body

Question 20

What separates the thorax from the lower part of the body?

Answer 20

the diaphragm

Question 21

What are the lungs surrounded by?

Answer 21

Pleural membranes

-protected by the ribcage (intercostal muscles run between the ribs)

Question 22

What is the journey which air which you breath in goes on?

Answer 22

• in through the trachea
• down a bronchus (trachea splits into two bronchi)
• down a bronchiole (bronchus splits into bronchioles)
• into an alveoli, where gas exchange takes place

Question 23

What happens in your thorax when you breath in?

Answer 23

• intercostal muscles and diaphragm contract

- thorax volume increases, this decreases the pressure, drawing air in

Question 24

What happens in your thorax when you breath out

Answer 24

• intercostal muscles and diaphragm relax

- thorax volume decreases, this increases the pressure, forcing air out

Question 25

Describe an experiment for how to investigate the effects of exercise on breathing rate:

Answer 25

- sit still for 5 mins,then measure heart rate for 1 min - do 4 mins of exercise and measure your heart rate again - repeat and work out the mean results (could try other people to compare results)

Question 26

Why does exercise increase your breathing rate?

Answer 26

- your muscles respire more - so they need more oxygen and need more carbon dioxide removed - so your breathing rate increases

Question 27

Describe an experiment for how to investigate the effects of respiration on the release of carbon dioxide in your breath:

Answer 27

- set up two boiling tubes with lime water in connected by pipes, and a mouth piece - breath in and out on the mouth piece several times - as you breath in tube A has air drawn from the room and therefore the limewater is still clear - as you breath out tube B turns cloudy as your breath contains carbon dioxide produced in respiration

Question 28

What gas exchange happens in the alveoli?

Answer 28

- blood passing the alveoli has just returned from the rest of the body so it has lots of carbon dioxide in - oxygen diffuses out of the alveolus into the red blood cells, carbon dioxide diffuses out of the blood plasma into the alveolus

Question 29

What gas exchange happens when blood reaches other parts of the body?

Answer 29

- oxygen is released from the red blood cells into the body cells - carbon dioxide diffuses out of the body cells into the blood, where it is carried back to the lungs

Question 30

How are alveoli specialised for gas exchange?

Answer 30

- huge number of them(microscopic) - large surface area - moist lining for gases to dissolve in - thin walls (one cell thick) - short diffusion distance - great blood supply - to maintain high concentration gradient - walls are permeable -gases diffuse easily

Question 31

What diseases can smoking cause?

Answer 31

- emphysema - chest infections - chronic bronchitis - coronary heart disease - cancer

Question 32

How can smoking cause emphysema?

Answer 32

- smoking damages the walls inside the alveoli | - reducing the surface area for gas exchange

Question 33

How can smoking cause chest infections?

Answer 33

- tar in cigarettes damages cilia - cilia are essential for catching dust and bacteria in mucus in the trachea - also sweep mucus back towards the mouth

Question 34

How can smoking cause chronic bronchitis?

Answer 34

- tar irritates the bronchi and bronchioles | - this encourages mucus to be produced, which can't be cleared well by the damaged cilia

Question 35

How can smoking cause coronary heart disease?

Answer 35

- carbon monoxide in cigarette smoke reduces the amount of oxygen the blood can carry - to make up for this heart rate increases, leading to increased blood pressure - high blood pressure damages artery walls making blood clots more likely

Question 36

How can smoking cause cancer?

Answer 36

tabacco smoke also contains carcinogens (chemicals that lead to cancer)