Respiration

Question 1

Respiration

Answer 1

Respiration is the process of transferring energy from glucose to cells. The energy transferred via respiration is not used directly - instead it is used to make the substance ATP, which stores energy needed for many cellular processes.

Question 2

What are the differences between aerobic and anaerobic respiration?

Answer 2

Aerobic - happens when oxygen is available
Anaerobic - happens when oxygen is unavailable (i.e. when you are exercising heavily); is far les efficient than aerobic respiration

Question 3

Aerobic respiration word and symbol equations

Answer 3

Glucose + Oxygen — Carbon dioxide + Water (+ Energy)

C6H12O6 + 6O2 — 6CO2 + 6H2O

Question 4

Anaerobic respiration (in animals) word equation

Answer 4

Glucose — Lactic acid (+ Energy)

Question 5

Anaerobic respiration (in plants and fungi) word equation

Answer 5

Glucose — Ethanol + Carbon dioxide (+ Energy)

Question 6

Experiment to show that respiration produces carbon dioxide

Answer 6

• One tube of germinating beans + one control tube (boiled beans).
• In each tube, the beans are placed on a gauze above some liquid hydrogen-carbonate indicator.
• In the presence of carbon dioxide, the hydrogen-carbonate indicator will change colour from orange to yellow.
• This will only happen in the tube with germinating beans, as boiled beans are not alive and thus cannot respire.

Question 7

Experiment to show that respiration transfers heat energy

Answer 7

• One vaccuum flask (sealed with cotton wool, but with some air left) of germinating beans + one of boiled beans.
• In each flask, there is a thermometer.
• In the flask with germinating beans, the temperature will increase over time (as respiration gives out heat).