New
New
Year 11
Edexcel
Higher

The effect of temperature on cellular respiration in small organisms: practical

I can use a simple respirometer to investigate the effect of temperature on cellular respiration in small living organisms.

New
New
Year 11
Edexcel
Higher

The effect of temperature on cellular respiration in small organisms: practical

I can use a simple respirometer to investigate the effect of temperature on cellular respiration in small living organisms.

Lesson details

Key learning points

  1. Effect of temperature on aerobic cellular respiration investigated in small living organisms (e.g. germinating peas).
  2. The oxygen used by the respiring organisms in a set time can be measured using a simple respirometer.
  3. Identifying independent and dependent variables, and variables to control to increase the validity of the results.
  4. The height of coloured liquid in the capillary tube of the respirometer is measured at the start & end of the set time.
  5. Collecting repeat measurements at each temperature, and collecting data at different temperatures.

Common misconception

That small organisms and plants don't respire (only humans and other large animals).

This lesson demonstrates experimentally that small organisms respire.

Keywords

  • Aerobic - A process that requires oxygen.

  • Cellular respiration - An exothermic chemical process that transfers energy for life processes, using glucose as fuel.

  • Respirometer - Apparatus used to measure the rate of respiration in small organisms.

  • Independent variable - The factor that we change in an experiment.

  • Dependent variable - The factor that we measure in an experiment.

In order to speed up the practical, you can divide the class in half and have one half conduct the experiment at 25 degrees, and the other half conduct the experiment at 35 degrees.
Teacher tip

Equipment

Boiling tubes, small living organisms, cotton wool, soda lime, bungs, capillary tubes, dye, water bath, marker pen, ruler, timer.

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Where does anaeroboc respiration take place?
mitochondria
ribosomes
Correct answer: cytoplasm
chloroplasts
Q2.
Respiration occurs continuously in the cells of every living organism. The energy transferred is needed for life processes. Which life process does not need energy transferred from respiration?
active transport
building proteins from amino acids
muscle contraction
Correct answer: photosynthesis
Q3.
Whhat are the reactants in aerobic cellular respiration?
carbon dioxide and oxygen
carbon dioxide and glucose
Correct answer: oxygen and glucose
oxygen and water
Q4.
What is the product of anaerobic cellular respiration in animal cells?
carbon dioxide
ethanol
glucose
oxygen
Correct answer: lactic acid
Q5.
Which two words complete this sentence? Anaerobic cellular respiration is a __________ process, so is a __________ way to transfer energy.
longer
Correct answer: shorter
Correct answer: faster
slower
Q6.
We make use of fermentation in yeast to make some foods and drinks. Which product of fermentation causes bread to rise?
Correct answer: carbon dioxide
ethanol
glucose
lactic acid
oxygen

6 Questions

Q1.
Look at the unbalanced equation for aerobic respiration. Which number in front of the CO$$_2$$ and H$$_2$$O would balance the equation?
An image in a quiz
2
4
Correct answer: 6
8
Q2.
The rate of cellular respiration is affected by temperature. Which is the best explanation for this?
Chemical reactions are all affected by temperature.
Organisms can die if they get too cold or too hot.
Cellular respiration is exothermic.
Correct answer: Cellular respiration is catalysed by enzymes.
Q3.
The diagram shows part of the apparatus used in the investigation. What is the function of the soda lime?
An image in a quiz
Correct answer: to absorb carbon dioxide from cellular respiration
to absorb oxygen from cellular respiration
to provide oxygen for cellular respiration
to provide carbon dioxide for cellular respiration
Q4.
The water bath in the apparatus is needed to keep the temperature constant because respiration is an exothermic reaction. Which statement about exothermic reactions is correct?
An image in a quiz
Correct answer: An exothermic reaction transfers heat to the environment.
An exothermic reaction absorbs heat from the environment.
To start the reaction, heat is needed.
To start the reaction, it needs to be cooled.
Q5.
The apparatus shown can be used to measure the effect of temperature on the rate of respiration. The steps of the method to use this apparatus are in the wrong order.
An image in a quiz
1 - Wait for the organisms to adjust to the temperature.
2 - Mark the starting positions of the coloured liquid in the capillary tubes.
3 - After 5 minutes measure the distance moved by the liquid in each capillary tube.
4 - Repeat at a different temperature.
Q6.
Match the words to their correct meaning.
Correct Answer:aerobic cellular respiration ,respiration that requires oxygen

respiration that requires oxygen

Correct Answer:anaerobic cellular respiration ,respiration that does not require oxygen

respiration that does not require oxygen

Correct Answer:cellular respiration ,chemical process that transfers energy from glucose for life processes

chemical process that transfers energy from glucose for life processes

Correct Answer:dependent variable ,the variable being tested or measured during an experiment

the variable being tested or measured during an experiment

Correct Answer:independent variable,the variable that is altered during an experiment

the variable that is altered during an experiment

Correct Answer:respirometer ,apparatus used to measure the rate of respiration

apparatus used to measure the rate of respiration

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