12.1 , 12.2 , 12.3

Question 1

respiration

Answer 1

• a chemical reaction that breaks down glucose in living cells to release energy

Question 2

aerobic respiration

Answer 2

• generate energy involving using oxygen
• glucose broken down with oxygen

glucose + oxygen > carbon dioxide + water + energy
C6H12O6 + 602 > 6CO2 + 6H2O + energy

Question 3

anaerobic respiration

Answer 3

• generate energy without using oxygen
• glucose broken down without oxygen

animals/human
- glucose > lactic acid + energy
C6H12O6 > 2C3H6O3 + energy

yeast/plant
- glucose > alcohol + carbon dioxide
C6H12O6 > 2C2H5OH + 2CO2 + energy

Question 4

ciliated cell

Answer 4

found in
- trachea
- nasal
- small intestine

Question 5

cilia

Answer 5

• traps germs / dust / bacteria
• waft to sweep the dust

Question 6

goblet cells

Answer 6

• produce mucus - traps dust

Question 7

lactic acid

Answer 7

• lactic acid is produced in muscle cells during anaerobic respiration, due to short supply of oxygen
• the more u exercise, the higher ur lactic acid concentration

e.g : during exercise > LA build up in muscle, when found in blood and muscle > pH drops (become acidic) > brain send signal to > heart to pump faster or lungs and intercoastal muscle to contract harder

Question 8

alveolus

Answer 8

• thin wall (one cell thick)
• large surface area

Question 9

inhalation

Answer 9

internal intercoastal muscles relax - external intercostal muscles contracts
—> pulls ribcage upwards and outwards
—> diaphragm contracts pulling downwards
—-> lung volume increas, air pressure decrease

Question 10

exhalation

Answer 10

• internal intercoastal muscles contracts - external intercostal muscles relax
  —-> pulls ribcage downwards and inwards
  —-> diaphragm relaxes moving back upwards
  —-> lung volume decrease, air pressure increases