Respiration Flashcards

All 12 cards in this deck

What is cellular respiration?

An exothermic reaction that happens continuously in all living cells, releasing energy for metabolic processes.
e.g. muscle contraction, making large molecules, active transport, keeping warm

Write the balanced symbol equation for aerobic respiration.

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$
glucose + oxygen → carbon dioxide + water

What are the word equations for anaerobic respiration in animals and in yeast?

Animals: glucose → lactic acid
Yeast (and plants): glucose → ethanol + carbon dioxide

Give three ways aerobic respiration differs from anaerobic respiration.

1. Aerobic uses oxygen, anaerobic does not.
2. Aerobic releases more energy (ATP).
3. Aerobic takes place in the mitochondria, anaerobic in the cytoplasm.

What is the oxygen debt built up during vigorous exercise?

The extra oxygen needed after exercise to break down the lactic acid produced by anaerobic respiration.

What are the steps to investigate the rate of respiration using hydrogencarbonate indicator?
e.g. comparing germinating peas with dried peas

1. Put equal masses of organisms on gauze above the same volume of indicator in sealed tubes: germinating peas, dried peas.
2. Leave for a set time at the same temperature.
3. Record the colour: red → yellow shows carbon dioxide released, so the germinating peas are respiring.

How is the rate of respiration worked out from a respirometer?

rate of respiration = distance moved by the coloured drop ÷ time taken (e.g. mm per minute)

What happens to the rate of respiration measured in a respirometer as the temperature is increased (up to about 40 °C)?

It increases — the enzyme-controlled reactions happen faster, so oxygen is used up more quickly.

In a respirometer or indicator investigation into respiration, what should the control contain?

The same apparatus set up with no living organisms — e.g. an equal mass of glass beads instead of the organisms.

What piece of equipment should be used to keep all tubes at the same temperature in a respiration investigation?

A water bath, so temperature is kept the same and results are comparable.

Why do muscles start to respire anaerobically during vigorous exercise?

Even with heart and breathing rates at their maximum, oxygen can't be delivered to the muscles fast enough for aerobic respiration alone to meet their energy demand.

In a respirometer, what is the soda lime for?

It absorbs the carbon dioxide the organisms give out, so any change in gas volume is caused only by the oxygen they take in.