Respiration Practice Questions

Cellular respiration is described as an exothermic reaction.

Which statement explains why cellular respiration is exothermic?

Put a cross ( ☒ ) in the box next to your answer.

☐ A it takes in energy from the surroundings

☐ B it releases energy

☐ C it produces energy

☐ D it uses light energy

State two metabolic processes in the human body that use the energy released by cellular respiration.

Complete the word equation for aerobic respiration.

glucose + .............................. → .............................. + water

Balance the symbol equation for aerobic respiration by writing the missing numbers.

$\mathrm{C_6H_{12}O_6} + \ldots \mathrm{O_2} \rightarrow \ldots \mathrm{CO_2} + \ldots \mathrm{H_2O}$

Write the word equation for anaerobic respiration in yeast.

Yeast cells can also respire aerobically.

State two differences between aerobic respiration and anaerobic respiration in a yeast cell.

The sealed vessel has a valve fitted in the lid that allows gas to escape but does not let air in.

Explain why this valve is needed.

At the start of the investigation the drop of coloured liquid was at the $12\ \mathrm{mm}$ mark on the scale. After 15 minutes the drop was at the $57\ \mathrm{mm}$ mark.

Calculate the mean rate of movement of the drop in mm per minute.

Explain why soda lime is needed in the respirometer.

The student placed the whole respirometer in a water bath at $20\ ^\circ\mathrm{C}$.

Explain why this was done.

State the colour of the hydrogencarbonate indicator in tube A after 18 minutes.

Explain how the colour change of the indicator shows that the organisms were respiring.

The student concluded that maggots respire faster than woodlice.

Give three ways the method could be improved so that this conclusion is more valid.

Explain why the concentration of lactic acid in her blood increased during the race.

Immediately after the race the athlete continued to breathe deeply and quickly for several minutes.

Explain why.

During the race the blood flow to her leg muscles increased.

Explain why an increased blood flow to the muscles is needed during exercise.

Identify the anomalous result and give a reason for your choice.

Explain why increasing the concentration of the glucose solution increased the height of the foam produced.

Suggest one change the student could make to this investigation to increase the rate of respiration of the yeast.

Plot these results on the grid and draw a suitable curve.

Describe the trend shown by these results.

Before counting the bubbles, the student left the apparatus in the water bath for five minutes at each temperature.

Give a reason why.

Compare the process of aerobic respiration with the process of anaerobic respiration in human muscle cells.

Use word equations in your answer.

Calculate the rate of oxygen uptake by the germinating mung beans in $\mathrm{mm^3}$ of oxygen per gram per hour.

Explain why the scientist expressed her result per gram of beans.

Calculate the percentage increase in the mean oxygen uptake of the mice when the air temperature falls from $25\ ^\circ\mathrm{C}$ to $5\ ^\circ\mathrm{C}$.

Explain the effect of the lower air temperature on the oxygen uptake of the mice.