Breathing and Respiration

Question 1

Order of levels of organisation

Answer 1

Organelle, cell, tissue, organ, organ system, organism

Question 2

What is ATP?

Answer 2

Chemical produced in respiration that acts as an energy ‘currency’.

Question 3

ATP full name

Answer 3

Adenosine triphosphate

Question 4

What processes use ATP? Give 4 examples

Answer 4

• ATP is used up by any process that requires an energy supply
• some examples include = muscle contraction, active transport, mitosis, and forming new molecules such as proteins in the ribosomes

Question 5

Word equation for aerobic respiration

Answer 5

Oxygen + glucose => carbon dioxide + water

Question 6

Balanced symbol equation for aerobic respiration

Answer 6

6O2 + C6H12O6 => 6CO2 + 6H2O

Question 7

Anaerobic respiration in plants and fungi equation

Answer 7

Glucose => carbon dioxide + ethanol

Question 8

Anaerobic respiration for animals word equation

Answer 8

Glucose => lactic acid

Question 9

Describe the germinating seeds experiment

Answer 9

• 2 bottles of seeds are kept- one boiled and one germinating and they both have thermometers in them
• the one that is germinating has a higher temperature on the thermometer than the boiled seeds

Question 10

Explain the reason why the temp was higher in the germinating seeds than the boiled ones

Answer 10

The germinating seeds were alive. This means that they were respiring so therefore heat was produced. However the boiled seeds are dead, meaning that they weren’t respiring. This meant that the temperature would remain the same.

Question 11

What was the purpose of having boiled seeds?

Answer 11

Boiled seeds were kept as a control to compare the results and show that the results changed because of the independent variable

Question 12

Describe the yeast experiment

Answer 12

• yeast in a sugar solution was kept in a test tube + liquid paraffin was floating on top of the yeast solution
• attached to the yeast test tube was a test tube containing limewater /hydrogen carbonate indicator

Question 13

Explain the results of the yeast experiment

Answer 13

The liquid paraffin layer prevents the entry of oxygen to the yeast. This forces the yeast to respire anaerobically. The yeast will produce CO2 and ethanol. The co2 will bubble through the paraffin and will transfer into the limewater/ hydrogen carbonate indicator. The limewater will go cloudy or the hydrogen carbonate solution will turn yellow in the presence of CO2.

Question 14

What colour does hydrogen carbonate indicator turn when co2 levels are higher than atmospheric?

Answer 14

Yellow

Question 15

What colour does hydrogen carbonate indicator turn when co2 levels are same as atmospheric?

Answer 15

Red

Question 16

What colour does hydrogen carbonate indicator turn when co2 levels are lower than atmospheric?

Answer 16

Purple

Question 17

Describe the breathing and exercise experiment

Answer 17

• C = intensity of exercise (step ups) as no, gentle and intense exercise (steps ups for 30s & 60s respectively)
• O = 1 13yr old girl (human)
• R = 3 repeats at each intensity to improve the reliability and accuracy
• M = breathing rate over 1 min by counting no. of breaths/ min manually
• S = control variables : type of exercise, temp, fitness level, no medical condition affecting breathing rate

Question 18

Explain diffusion in gas exchange in alveoli

Answer 18

• air w/ oxygen in it enters alveolus so there’s a high conc. in the alveolus and low conc. in blood
• so oxygen will diffuse into blood
• deoxygenated blood w/ co2 in will pass through the capillaries near alveolus so there’s a high conc. in blood and low in alveolus
• so co2 will diffuse out of the blood and will be exhaled

Question 19

How does the alveoli maintain a high concentration gradient between the blood and the alveoli?

Answer 19

ventilation and rich blood supply

Question 20

What is the net exchange of gasses dependent on?

Answer 20

• the net exchange of gasses is dependent on how much light is available
• this is because respiration occurs 24/7 so oxygen enters the leaf and co2 exits it
• however photosynthesis only happens when light is present so co2 enters and oxygen exits the leaf

Question 21

What is ventilation?

Answer 21

Breathing or ventilation is the physical process of air moving into and out of the thorax

Question 22

What muscles in the thorax are involved in ventilation?

Answer 22

Diaphragm and the intercostal muscles

Question 23

What happens to thorax in inhalation (physically and w/ pressure + volume)?

Answer 23

• intercostal muscles contract and move the rib cage up and out
• the diaphragm contracts and flattens
• this causes pressure to decrease and volume to increase so air is drawn into the lungs
• lungs inflate

Question 24

What happens to thorax in exhalation (physically and w/ pressure + volume)?

Answer 24

• intercostal muscles relax and move the rib cage down and in
• the diaphragm relaxes and domes
• this causes pressure to increase and volume to decrease and air rushes out of the thorax as pressure in the thorax is higher than outside it
• lungs deflate

Question 25

How does smoking cause chest infections and bronchitis?

Answer 25

- tar in cigars damages cilia - paralyses the cilia = they can’t beat rhythmically to waft the mucus away from the lungs which causes a mucus buildup - smoke can irritate airways causing goblet cells to secrete more mucus causing smokers cough, chest infections and bronchitis

Question 26

How does smoking cause emphysema?

Answer 26

- smoke breaks down the walls of the alveoli so that they fuse together into one irregular large space - less oxygen diffuses into blood as the surface area of the alveoli has decreased dramatically - this causes fatigue and breathlessness

Question 27

How does smoking cause lung cancer?

Answer 27

- caused by smoke containing carcinogens such as tar, nicotine and CO - the carcinogens mutate the DNA and cause it to replicate uncontrollably until a tumour is created - this reduces the lungs’ capacity to diffuse oxygen into the blood

Question 28

How does smoking cause CO poisoning?

Answer 28

- carbon monoxide can be found in cigarette smoke - CO reduces the blood’s capacity to transport O2 around the body - CO binds to the haemoglobin more readily then O2 does - irreversibly forms carboxyhemoglobin so less oxygen is transported around the body

Question 29

How does smoking affect the circulatory system?

Answer 29

- smoke contains carcinogenic chemicals such as nicotine - nicotine is an addictive substance that narrows blood vessels and increases blood pressure - high blood pressure damages the arteries and causes a fatty deposit to build up in damaged areas - this can clog the arteries and therefore cause coronary heart disease

Question 30

Method for the breathing rate experiment

Answer 30

1. Measure number of breaths per minute at resting 2. Do exercise for specified amount of time 3. Measure number of breaths per minute directly after exercising every minute until they reach normal 4. Repeat 3 times overall (e.g. = 0s, 30, 60s of steps-ups)

Question 31

What is the oxygen debt?

Answer 31

Volume of oxygen required to completely oxidise the lactic acid produced in anaerobic respiration

Question 32

Aerobic respiration- does it use oxygen?

Answer 32

Yes, as it’s a chemical reaction between oxygen and glucose that releases energy all cells

Question 33

Aerobic respiration - what are its products?

Answer 33

Carbon dioxide and water

Question 34

Aerobic respiration - does it release more or less ATP than anaerobic?

Answer 34

It releases more ATP than anaerobic as the glucose is completely oxidised here.

Question 35

Alveoli have thin walls - how thin are they + why does this help in gas exchange?

Answer 35

- walls of alveoli are only one cell thick - this provides a shorter diffusion distance for gasses, and increases rate of diffusion

Question 36

Alveoli have a rich blood supply - what type of blood vessel are they covered in + how does this help with gas exchange?

Answer 36

- they are covered in many capillaries - allows oxygenated blood to be taken away from alveoli and deoxygenated blood to come towards them - this maintains a high concentration gradient

Question 37

Alveoli have a large surface area - how does this help them with gas exchange?

Answer 37

- there are millions of alveoli in the lungs meaning that they have a large SA - this means that a larger volume of gasses can diffuse into and out of the blood at one time

Question 38

Leaves are broad - how does this help them with gas exchange?

Answer 38

Allows for a large surface area of diffusion for gasses

Question 39

Leaves are thin - how does this help them with gas exchange?

Answer 39

Allows for a shorter diffusion distance for gasses

Question 40

Leaves have lots of stomata - how does this help with diffusion?

Answer 40

Increases surface area and entry points for gasses and guard cells open and close them to prevent water loss