Biology - Respiration and the respiratory system

Question 1

What is the purpose of respiration?

Answer 1

Provides the energy required for movement, respiration, growth, reproduction and
-muscle contraction, required for movement
-nerve impulses, required for sensitivity and responding
-cell division and protein synthesis, required for growth

Question 2

What is respiration?

Answer 2

Respiration involves chemical reactions that break down nutrient molecules in living cells to release energy.

Question 3

What is aerobic respiration?

Answer 3

Aerobic respiration needs oxygen. It is the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen.

Question 4

What is the equation for aerobic respiration?

Answer 4

Glucose + oxygen -> Carbon dioxide + water + energy in the form of ATP

Question 5

How is ATP formed?

Answer 5

If the energy stored in glucose were released all at once it would be very difficult to contain. Therefore, the energy stored in the glucose molecule is released gradually during respiration and Is used to form ATP.

Question 6

What is ATP?

Answer 6

ATP is the energy currency of the cell. It temporarily stores the energy in a high energy bond, and when this bond is broken, small amounts of energy are released and used by the body.

Question 7

What cell is used for respiration in animals and plants.

Answer 7

Mitochondria.
The inner membrane is folded inwards, providing a large surface area for the attachment of enzymes which catalyse the process of respiration.

Question 8

What is anaerobic respiration?

Answer 8

Anaerobic respiration does not need oxygen (unlike aerobic respiration). It is the release of a relatively small amount of energy in cells by the breakdown of food substances in the absence of oxygen.

Question 9

What is the equation for anaerobic respiration?

Answer 9

Glucose -> lactic acid + energy in the form of ATP.

Question 10

What does the creation of lactic acid do?

Answer 10

Generates an oxygen debt that needs to be repaid after the exercise is finished. This is why we keep on breathing deeply for a few minutes after we have finished exercising.

Question 11

When would anaerobic and aerobic respiration occur?

Answer 11

Anaerobic - short intense exercise like sprinting
Aerobic - low intensity exercise like slow, steady running.

Question 12

What is an oxygen deficit?

Answer 12

The difference between the oxygen the body needs during the sudden sprint and what it actually managed to take in.

Question 13

What are the main differences between aerobic and anaerobic respiration?

Answer 13

Aerobic - Oxygen needed , Glucose broken down, end product Carbon dioxide and water , Relatively large amount energy from each glucose molecule.

Anaerobic - oxygen not needed, glucose breakdown incomplete, end product Animal cells - lactic acid. Plant cells and yeast - carbon dioxide and ethanol. Relatively small amount energy from each glucose molecule

Question 14

What is an experiment used to detect Carbon dioxide in respiration?

Answer 14

Carbon dioxide is bubbled through limewater then it turns from clear to cloudy/milky in colour. This is why limewater used in a simple respirometer can show that more carbon dioxide is present in exhaled air compared to inhaled air.

Breathing in through the mouthpiece draws air from the atmosphere in through tube A. Breathing out through the mouthpiece bubbles exhaled air through tube B. After a few breaths the limewater in tube B will turn cloudy as the exhaled air contains more carbon dioxide.

Question 15

What is an experiment for aerobic respiration?

Answer 15

-Disinfect peas. This will kill any bacteria on their surface so that they don’t respire in the flask.
-Pour the fresh peas into one flask and the same mass of boiled peas into another. The flask with boiled peas is the controlled experiment, used as a comparison.
-Boiling denatures the enzymes needed for respiration.
The vacuum of the flask insulates the peas from
outside changes in temperature.
-Place a thermometer into the mass of peas in each flask, and seal with a plug of cotton wool. Take a
reading and note the temperatures of both flasks at intervals throughout the experiment. The results should reveal that the flask filled with fresh ‘germinating’ peas will have increased in temperature, whereas the flask filled with boiled peas will have remained the same. You have just seen aerobic
respiration in action.

Question 16

What is the order of body parts as you breath?

Answer 16

Nasal cavity
trachea
bronchi
bronchioles
alveoli

Question 17

What structures does ventilation require?

Answer 17

ribs
intercostal muscles
diaphragm

Question 18

What adaptions does the trachea have?

Answer 18

-Cartilage rings in the walls of the trachea help to keep it open
-Cilia and goblet cells to clean the air before it reaches the lungs

Question 19

How do the cilia and goblet cells clean the walls of the trachea?

Answer 19

-Goblet cells produce mucus which traps dust, dirt and bacteria to prevent them entering the lungs.

-Cilia are small hairs which beat to push the mucus back up the trachea so it can be swallowed and destroyed in the stomach.

Question 20

What happens when you inhale?

Answer 20

-The intercostal muscles contract, pulling the ribcage upwards and outwards
-The diaphragm contracts, pulling downwards
-Volume of the thorax increases and the pressure inside decreases
-Air is drawn into the lungs down a pressure gradient

Question 21

What happens when you exhale?

Answer 21

-The intercostal muscles relax pulling the ribcage downwards and inwards
-The diaphragm relaxes, doming upwards
-Volume of the thorax decreases and the pressure inside increases
-Air is pushed out of the lungs

Question 22

How does the bell jar experiment work?

Answer 22

The model, which is air tight, represents the thorax, and air is only able to enter via the glass tube which represents the trachea.

As the rubber sheet is pulled down the volume of the jar increases, the pressure therefore decreases and air is drawn in through the glass tube inflating the balloons, which represent the lungs.

Question 23

What is the difference between atmospheric air and exhaled air?

Answer 23

Atmospheric air
-Nitrogen 79%
-Oxygen 21%
-Carbon dioxide 0.04%

Exhaled air
-Nitrogen 79%
-Oxygen 16%
-Carbon dioxide 4%

Question 24

What are some of the features of the alveoli?

Answer 24

large surface area for maximum exchange of gases
moist surface for the dissolving of gases in alveolar air so that they can diffuse across the alveolar walls
rich blood supply to remove diffused gases and maintain a concentration gradient for further diffusion

Question 25

How does gas exchange happen in the alveoli?

Answer 25

Capillaries carry deoxygenated blood. Via diffusion, the carbon dioxide goes into the alveoli and oxygen goes from the alveoli into the capillary. Capillaries then carry oxygenated blood.

Question 26

What is the affect of smoking on the air passages?

Answer 26

-Cigarette smoke paralises cilia leading to a build-up of mucus and a smoker’s cough.
-Smoke irritates the bronchi, causing bronchitis.
-Sticky mucus in the lungs traps pathogens.(microorganisms that cause diseases.

Question 27

What is the affect of smoking on the alveoli?

Answer 27

Smoke damages the walls of the alveoli. The alveoli walls break down and join together, forming larger air spaces than normal. This reduces the ability of the blood to carry oxygen, putting a strain on the heart which increases the risk of developing coronary heart disease or strokes.

Question 28

What is the affect of carbon monoxide on red blood cells?

Answer 28

Carbon monoxide, CO, combines with the haemoglobin in red blood cells. This reduces the ability of the blood to carry oxygen, putting a strain on the heart, which increases the risk of developing coronary heart disease or strokes.

Question 29

How does lung cancer develop?

Answer 29

Tobacco smoke contains many carcinogens, including tar. Smoking increases the risk of lung cancer, and cancer of the mouth, throat and oesophagus.