Biology - Cellular Respiration Worksheet (for Corresponding Virtual Experiment) PDF

Preview

Summary

adASDadaSDa...

Description

Cellular Respiration Experiment Task You are to conduct a virtual experiment that investigates the impact of temperature on the rate of cellular respiration.

Part I - Planning

A) Background information

The image on the right shows a respirometer. It consists of a test tube that is tightly sealed by a holed stopper connected to a slim volumetric glass pipe similar to a pipette. The glass tube is open to the air on the other end. Both, the test tube and the glass pipe are filled with air. Inside the test tube is a layer of potassium hydroxide flakes covered by a layer of cotton wool. Potassium hydroxide (KOH) absorbs carbon dioxide gas. For this experiment germinating peas are placed inside the respirometer. A drop of food colouring is placed the open end of the glass tube. This droplet completely seals off the tube from the outside air. The respirometer will be placed into spaces with different temperatures. The temperature of each space is measured with a thermometer.

at

A1) What is the independent variable for this experiment?

A2) What is the dependent variable for this experiment?

A3) Explain at least 2 conditions that should be kept the same for this experiment (= controlled variables).

A4) Suggest at least one control needed to confirm reliability in this experiment.

A5) State the general chemical equation for cellular respiration

A6) Describe the three steps of cellular respiration (name, location, inputs, outputs)

A7) a) Which of the three steps (either one, two or all) will be affected by different temperatures

b) Justify your answer to a) by explaining which changes occur to inputs and/or outputs under HIGH temperature conditions.

A8) Based on your explanations in A7, summarise how the rate of respiration is expected to change with increasing temperatures.

B) Experimental design B1) Explain the purpose of the potassium hydroxide (KOH) for this experiment..

B2) Explain what will happen to the food colouring droplet inside the glass tube over time. Justify why this should happen.

B2) What is measured with the graduation  (scale) on the glass tube? 

B3) In addition to the measurement suggested in B2, which other measurement is needed to calculate respiration rate?

C) Test run the experiment Download the slide show C1) Read and take note of all  displays and the differences  between set-ups. C2) Decide how you will take consistent and precise readings.

D) Plan the data collection In your planning consider the following: You will have to take measurements for 3 different time points. You will have to continue this procedure for  each, set-up 1, 2 and 3. D1) Which measurements do you need to record for each set-up?

D2) Which calculations do you need to make from these measurements?

D4) Which measurements or calculations represent the independent  variable? 

D5) Which measurements or calculations represent the dependent  variable? 

D6) Design a data table appropriate to collect all measured and calculated data for this task. You may generate your table either digitally in EXCEL or similar software or manually using pencil and ruler on grid paper. Your table must: ● include accurate column headings and row titles incl. units. ●

clearly indicate which measurements for the same set-up (i.e. repeats), and which ones are from different setups.

●

clearly identify dependent and independent variables.

●

allow calculation of means, where needed.

●

show the equations for any calculations carried out.

Part II - Conducting the Experiment & Data Recording You are now ready to conduct the e  xperiment. You must collect data for at least 3  different time points for each set-up.

If needed, use the forward

and backward

keys on your keyboard

to restart measurements for a set-up, or to  move between setups. 1) Record all measurements in your table. 2) Carry out any calculations and finalise your table.

Part III - Data presentation and analysis a) Decide which data from your table is best used to generate a graph. b) Is this data qualitative  or quantitative data? 

Why?

c) Is this data discrete  or continuous data? 

Why?

d) Which type of graph is best suited to represent your data?

Why?

e) Construct a graph, making sure you include appropriate axes, labels and scale markings. You may choose to generate this graph in EXCEL or manually, using pencil and ruler on grid paper....