Respiration

Question 1

What is respiration?

Answer 1

• exothermic reaction which is continuously occurring in living cells

Question 2

Why do organisms need to respire?

Answer 2

• chemical reactions to build larger molecules
• movement (muscle contraction)
• active transport
• keeping warm

Question 3

What are the equations for aerobic respiration?

Answer 3

C6H12O6 + 6O2 –> 6CO2 + 6H2O
glucose + oxygen -> carbon dioxide + water

Question 4

Where does aerobic respiration take place in?

Answer 4

mitrochondria

Question 5

What happens to glucose during aerobic respiration?

Answer 5

completely oxidised

Question 6

What happens to glucose during anaerobic respiration?

Answer 6

oxidisation is not complete

Question 7

Compare aerobic and anaerobic respiration

Answer 7

• aerobic = more energy released per glucose molecule, completely oxidised glucose, ample oxygen
• anaerobic = less energy released per glucose molecule, incomplete oxidation glucose, low oxygen levels

Question 8

What is the equation for anaerobic respiration in animals?

Answer 8

glucose -> lactic acid

Question 9

What is the equation for anaerobic respiration in plants and yeast cells?

Answer 9

glucose -> ethanol + carbon dioxide

Question 10

What is anaerobic respiration in yeast cells called?

Answer 10

fermentation

Question 11

What is fermentation used to make?

Answer 11

bread and alcoholic drinks

Question 12

Why is there an increase in demand for oxygen when we exercise?

Answer 12

• muscles contract more
• increased demand for energy
• rate of aerobic respiration increases

Question 13

How does the body respond to the increased demand for oxygen?

Answer 13

• breathing rate and volume increase = increase oxygen supply from air
• heart rate increase = supply more oxygenated blood to muscles

Question 14

Describe oxygen debt

Answer 14

• exercise hard/ long time = heart and breathing can’t keep up with demand for oxygen
• muscles become fatigued and stop contracting efficiently
• anaerobic respiration takes place
• produces lactic acid
• extra oxygen needed to remove lactic acid when exercise stops

Question 15

How is lactic acid removed?

Answer 15

• blood flows through muscles, removes lactic acid from muscles
• takes it to liver
• converted into glucose (oxygen needed)

Question 16

What is metabolism?

Answer 16

• sum of all chemical reactions in the cells of an organism

Question 17

What is glucose used for in plants?

Answer 17

• glucose molecules joined together, makes starch for energy storage (releases glucose for respiration)
• respiration
• making cellulose for cell walls

Question 18

What is glucose used for in animals?

Answer 18

• making glycogen
• can be broken down to release glucose for respiration
• respiration

Question 19

How do animals get amino acids?

Answer 19

• digestion of food
• new proteins are made

Question 20

How do plants get amino acids?

Answer 20

• nitrates from soil + glucose from photosynthesis

Question 21

What happens to excess proteins in animals?

Answer 21

• broken down
• produces urea which is excreted

Question 22

How are lipid molecules synthesised?

Answer 22

• one molecule of glycerol
• three fatty acid molecules
• made from products of photosynthesis/ digestion

Question 23

What can break lipids down?

Answer 23

lipase