Respiration

Question 1

Anaerobic respiration equation in muscles

Answer 1

glucose → lactic acid + small amount of energy

C6H12O6 → 2C3H6O3

Question 2

Anaerobic respiration equation in yeast

Answer 2

glucose → ethanol + carbon dioxide + small amount of energy

C6H12O6 → 2C2H5OH + 2C02

Question 3

Definition of aerobic respiration

Answer 3

Breakdown of food substances in presence of oxygen with release of a large amount of energy. Carbon dioxide and water are released as waste products

Question 4

Definition of anaerobic respiration

Answer 4

Breakdown of food substances in absence of oxygen with release of small amt of energy

Question 5

Desrcibe passage of air

Answer 5

atmosphere –> external nostril –> nasal passges –> pharynx –> larynx –> trachea –> bronchi –> bronchioles –> alveoli –> alveolus

Question 6

Equation of aerobic respiration

Answer 6

C6H12O6 + 6O2 –> 6CO2 + 6H2O + large amounts of energy

Question 7

Expiration

Answer 7

Diaphragm muscle relax, diaphragm arches upwards
External intercostal muscle relax, internal contract
Rib move downwards and inwards, sternum moves back to original position
VOlume of thoracic cavity decreases
Air pressure in lungs increases
Atmosphereric pressure is lower than pressure in lungs, air rush out of lungs

Question 8

Fate of lactic acid during muscle respiration

Answer 8

Lactic acid buildup in muscles
Increased acidity in muscle tissue reduces the ability of muscle fibres to contract (fatigue)
Lactic acid is tranported in blood plasma to liver
Some lactic acid goes thru aerobic respiration pathway to form co2 and H2o
Most lactic acid is onverted back to glucose and stored as glycogen

Question 9

How are the o2 and CO2 concentration graidents set up between blood and alveolar air (2)

Answer 9

Continuous flow of blood thru blood capillaries

Movement of air in and out of alveoli thru breathing

Question 10

How does the epithelium filter air

Answer 10

Gland/globet cells secrete mucus trap dust particles and bacteria
Clilliated cells have cillia on surface, which sweep dust-trapped mucus up the trachea, swalloed into the oesophagus

Question 11

How is oxygen absorped

Answer 11

Disssolv ein moisture lining alveolar walls
Diffuse across the 1 cell thick alveloar wall and capilary wall into blood plasma
combine with haemogoblin to form oxyhaemogoblin
In oxygen-poor tissues, oxyhaemo goblin releases oxygen which diffuse across capilary walls into body cells

Question 12

Inspiration (6)

Answer 12

Diaphragm muscle contracts, diaphragm move downwards
External intercostal muscle contract, internal relax
Rib move upwards and outwards, sternum moves up and forward
VOlume of thoracic cavity increases
Air pressure in lungs decreases
Atmosphereric pressure is higher than pressure in lungs, air rush into lungs

Question 13

Oxygen Debt

Answer 13

After strenous exercise, a person’s heart rate and breathing rate do not return to normal straight away
This is because oxygen is requred to remove the lactic acid and replenish the body’s reserves of oxygen.
During oxygen debt, person faces muscle fatigue

Question 14

Wha happens when yeast anaerobically respire for a longtim

Answer 14

Buildup of ethanol iis toxic to yeast as yeast cannot metabolise ethanol

Question 15

What are some adaptations for efficient gas exchange

Answer 15

many alveoli n lungs provide a large surface area
Wall of alveolus and blood cap is only 1 cell thick. Short diffusion distance –> Faster diffusion rate.
Thin film of moisature on surface of alveolus allow oxygen gas to dissolve in it
Walls of alveoli supplied by dense network of blood cap. Continuous flow of blood maintains conc grad of gases.

Question 16

What happens during muscle respiration

Answer 16

During high intensity physical exercise, your mscle cells require a lot of energy in a short amount of time
Insufficient oxygen is transported to the muscles. Aerobic respiration is unable to rlease energy fast enuf for muscles fibres to contract at a fast rate.
Hence, muscles cells carry out anaerobic resp n conjunction with aerobic resp to release extra energy for a limited amt of time

Question 17

Whats cellular respiration

Answer 17

A series of catabolic reactions in living cells that break down nutrients too release energy

Question 18

Why are trachea and bronchi supported by C-shaped rings of cartilage

Answer 18

How are trachea and bronchi kept open

Question 19

Why breathing thru nost better than breathing thru mouth (4)

Answer 19

Nostrils lead to 2 nasal passages that are lined with a moist mucous membrane
Dust and bacteria trapped by hairs and mucus
Air is warmed and moistened before entering lungs
Harmful chemicals may be detected by sensory cells in mucous membrane

Question 20

What nicotine cause

Answer 20

Highly addictive

cause release of adrenaline, constrict blood vessels
Increas eheart rate and heat pressure

Increase blood cholestrol
Increase fatty deposits in arteries (atherosclerosis)

Increase fibrinogen and platelets lvls
blood clot easily

Increased risk of coronary heat disease

Question 21

Carbon monoxide

Answer 21

Bind irreversibly with haemogoblin to form carbooxyhaemogoblin
Decrease ability of blood toc arry oxygen

Question 22

Chronic bronchitis

Answer 22

caused by prolonged exposure to irritant particles in tobacco smoke

Epithelium of trachea and bronchi become inflamed
airway narrower and less elastic

Gland Cells secrete excess mucus

Cillia paralysed, mucus and dust particles cant be removed

Mucus accumulate and obstruct air passsages, cause difficulty breathing. Mucus may be infected with bacteria

Persistent coughing to clear air passages, causing further inflammation