Respiration Flashcards

All 11 cards in this deck

What is cellular respiration?

An exothermic reaction that occurs continuously in all living cells, releasing energy from glucose for metabolic processes.

Give four uses in the body of the energy released by respiration.

Movement (muscle contraction), synthesis of larger molecules, active transport, and keeping warm.

What are the word and balanced symbol equations for aerobic respiration?

glucose + oxygen $\rightarrow$ carbon dioxide + water

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$

What are the word equations for anaerobic respiration in muscle cells and in yeast/plant cells?

Muscle cells: glucose $\rightarrow$ lactic acid

Yeast/plants: glucose $\rightarrow$ ethanol + carbon dioxide

True or false? Anaerobic respiration releases more energy per glucose molecule than aerobic respiration.

False. Aerobic respiration releases much more energy, because the glucose is broken down completely.

During vigorous exercise, what causes lactic acid to build up in muscle cells?

Oxygen cannot be delivered fast enough, so the muscle cells respire anaerobically.

In a respirometer, what is the purpose of the soda lime?

To absorb the carbon dioxide produced, so any decrease in gas volume is due only to the oxygen used.

What control should be used in a respirometer investigation into the rate of respiration of small organisms?

The same apparatus set up with no living organisms (e.g. glass beads) in place of the organisms.

True or false? A respirometer should be kept in a water bath at a constant temperature.

True. Temperature affects the rate of respiration, so it must be controlled (it also stops gas expanding as the apparatus warms).

What are the steps to calculate the rate of respiration from respirometer results?

e.g. the coloured drop moves 2.5 cm in 10 minutes

1. Read the distance moved and convert the units: $2.5$ cm $= 25$ mm
2. Divide by the time taken: $25 \div 10$
3. Rate $= 2.5$ mm per minute

What happens to an organism's oxygen consumption as its body temperature rises?

It increases, because enzyme-controlled metabolic reactions speed up so more respiration occurs.