respiration

Question 1

examples of processes driven by energy from respiration

Answer 1

1. anabolic reactions
2. active transport
3. movement
4. mantainance of body temperature

Question 2

define aerobic respiration

Answer 2

oxidation of glucose in the presence of oxygen with the release of a large amount of energy

Question 3

word and chemical eqn for aerobic respiration

Answer 3

word eqn:
glucose + oxygen —> large amount of energy + water + carbon dioxide

chemical eqn:
C6H12O6 + 6O2 —> large amount of energy + 6H2O + 6CO2

Question 4

definition of anaerobic respiration

Answer 4

breakdown of food substances in the absence of oxygen with the release of a relatively small amount of energy

Question 5

word eqn for anaerobic respiration in humans

Answer 5

glucose —> lactic acid + small amount of energy

Question 6

word eqn for anaerobic respiration in yeast

Answer 6

glucose —> ethanol + carbon dioxide + small amount of energy

Question 7

what happens to breathing rate during strenous exercise

Answer 7

1. muscles contract vigourously for faster movement, increased energy demand in muscles
2. breathing rate and heart rate increases to increase rate of respiration to release more energy
3. enables:
   - increased rate of oxygenated blood in lungs
   - increased rate of transport of oxygen and glucose to muscles
   - increased rate of removal of carbon dioxide produced

Question 8

what if the increase in oxygen uptake by aerobic respiration is unable to meet oxygen demand in muscles

Answer 8

1. anaerobic respiration releases the additional energy required for increased muscle contraction
2. causes accumulation of lactic acid in muscles that can lead to fatigue.

Question 9

why does breathing rate and heart rate remain high after exercise?

Answer 9

1. some lactic acid is sent to the liver to be oxidised into carbon dioxide and water
2. some lactic acid is converted into glucose and later glycogen for storage in liver and muscles.
3. addtional oxygen used to oxidise lactic acid is called oxygen debt
4. heart and breathing rate return to norm when all lactic acid has been oxidised (oxygen debt is paid)

Question 10

parts of respiratory system

Answer 10

• trachea
• pharynx
• larynx (voice box)
• diaphragm
• internal intercostal muscles
• external intercostal muscles
• bronchi
• bronchioles
• alveoli

Question 11

details of larynx (voice box)

Answer 11

• contains vocal chords

Question 12

details of trachea (windpipe)

Answer 12

• 12 cm long
• supported by C-shaped rings of cartilage, which reinforces front and side of airways, helping to protect it

Question 13

details of bronchi

Answer 13

• trachea divided into 2 bronchi, one to each lung

Question 14

epithelium of airways (trachea and bronchi) are lined with what and for what reason?

Answer 14

• mucus secreting cells
  traps dust and bacteria
• ciliated cells
  cilia on these cells sweep mucus up to the pharynx to be swallowed

Question 15

details of bronchioles

Answer 15

• each bronchus divides rapidly into very fine bronchioles

Question 16

details of alveoli

Answer 16

• clusters of air sacs at the end of bronchioles
• walls of alveoli are respiratory surfaces for gaseous exchange

Question 17

details of diaphragm

Answer 17

• sheet of muscular tissue attached to the thoracic cavity
• changes volume of thoracic cavity for breathing

Question 18

process of inhalation

Answer 18

1. diaphragm contracts and flattens
2. external intercostal muscles contract while internal intercostal muscles relax
3. ribs move upward and outward
4. volume of thoracic cavity increases
5. expansion of lungs cause air pressure inside to decrease
6. atmospheric pressure > pressure in lungs
7. air rushes into lungs

Question 19

process of exhalation

Answer 19

1. diaphragm relaxes and arches upwards
2. external intercostal muscles relax while internal intercostal muscles contract
3. ribs move inwards and downwards
4. volume of thoracic cavity decreases
5. pressure of air in lungs increases
6. atmospheric pressure < air pressure inside lungs
7. air rushes out of lungs and into atmosphere

Question 20

structural adaptations of alveoli and how they help

Answer 20

• one-cell thick wall: reduces diffusion distance for faster rate of diffusion of gases
• numerous alveoli: increases surface area to volume ratio for efficient gaseous exchange
• well supplied with capillaries: mantains steep concentration gradient for diffusion
• moisture on suface of inner walls: allows oxygen to dissolve in it

Question 21

transport of oxygen

Answer 21

1. oxygen dissolves in moisture lining alveolar walls
2. oxygen diffuses into capillaries
3. oxygen binds to haemoglobin in red blood cells to form oxyhaemoglobin

REACTION IS REVERSIBLE depending on amount of oxygen in surroundings.

when blood passes through oxygen-poor tissues, reaction will reverse to be released to tissues

Question 21

carbon dioxde to hydrogencarbonate reversible reaction

Answer 21

CO2 + H2O ⇌ (catalysed by carbonic anhydrase) H2CO3 ⇌ HCO3 + H

Question 22

details on carbonic anhydrase

Answer 22

• enzyme found in red blood cells
• catalyses reversible reaction between carbon dioxide and water to form carbonic acid

Question 22

ways carbon dioxide can be transported

Answer 22

1. as hyodrgencarbonate ions in the blood plasma (majority)
2. dissolving directly into blood plasma
3. binding to haemoglobin to form carbaminohaemoglobin

Question 23

how carbon dioxide is transported in body

Answer 23

1. in the **tissues, concentration of carbon dioxide and water is high**. **carbonic anhydrase catalyses formation of carbonic acid H2CO3 from CO2 and H2O** 2. **carbonic acid dissociates** to form **hydrogencarbonate ions and hydrogen ions.** **hydrogencarbonate ions diffuse out of red blood cells** and is carried in the **plasma.** 3. in the **lungs**, **hydrogencarbonate ions diffuse back into red blood cells** where they are converted into **carbonic acid.** **carbonic anhydrase** catalyses conversion of **carbonic acid into CO2 and H2O** 4. **CO2 diffuses out of capillary** into the **alveoli** and is **expelled during exhalation.**

Question 24

respiratory diseases caused by smoking?

Answer 24

1. **chronic bronchitis** 2. **emphysema** 3. **lung cancer**

Question 25

causes of respiratory diseases

Answer 25

* **smoking** * **continual exposure** and **inhalation of polluted air**

Question 26

symptomps of chronic bronchitis

Answer 26

1.**paralysed cilia** 2.**inflammation** of the **membrane** of **trachea and bronchi** 3.**excessive mucus** 4.**chronic cough** 5.**difficulty in breathing (narrowed airways)** 6.**lungs susceptible to infection** 7.may result in **emphysema** and **lung failure**

Question 27

signs and symptoms of emphysema

Answer 27

Developed from chronic bronchitis 1. **chronic coughing** from the **chronic bronchitis** 2. **breakdown** of the **partition walls of the alveoli** 3. **alveoli enlarged** and **surface area is reduced** 4. **lungs expand** and **lose elasticity** 5. **great difficulty in breathing** leading to **strain on the heart** 6. **lung tissue** is **damaged beyond repair**

Question 28

signs and symtomps of lung cancer

Answer 28

1. **uncontrolled growth of cells** in **small area of lungs** may **spread throughout lungs** and **block bronchioles** 2. **cancerous growth** may eventually **spread throughout body** 3. **difficulty breathing** 4. **blood in mucus in lungs**