Writing the procedure in a Lab Report Practical: Demonstration of the action of an enzyme

Lesson plan Level: Form 4 Lesson duration: 50mins Lesson Objective:   Lesson Objective: Learn to write procedure in lab report in passive voice and past tense. Summary of task / actions: Setting the context 1. Explain the differences between lab manual and lab report. 2. Explain why we use past tense and passive voice in lab report Modelling and deconstruction 1. Highlight words about action and what receives the action. 2. Constructing procedure in passive voice (with step 1-3 as example) Guided construction 1. Write procedure in passive voice (do step 4-6 together) Independent construction 1. Write procedure in passive voice (do step 7-11 independently)

The procedure or steps in an experiment A Lab manual, tells you what to do, so the writer uses the Imperative form, eg: Heat the test-tube. Add a drop of distilled water to a slide.

We will start with the procedures in the Lab menu Grind 10 g of fresh pig liver tissue in a mortar with 10 cm3 of cold distilled water. Filter the ground mixture by using muslin cloth to obtain the liver extract. Dilute the liver extract by adding 5 cm3 of cold distilled water. Label test tubes A to C. Add 5 cm3 of 3% hydrogen peroxide solution to test tubes A and B and add 5 cm3 of distilled water to test tube C. Add a few drops of diluted liver extract to test tubes A and C. Add a few drops of distilled water to test tube B. Cap the test tubes loosely with a stopper. Observe the evolution of gas bubbles. Wait for a while to collect enough gas. Test the gas produced in each tube with a glowing splint.

Highlight the actions and what receives the action Grind 10 g of fresh pig liver tissue in a mortar with 10 cm3 of cold distilled water. Filter the ground mixture by using muslin cloth to obtain the liver extract. Dilute the liver extract by adding 5 cm3 of cold distilled water. Label test tubes A to C. Add 5 cm3 of 3% hydrogen peroxide solution to test tubes A and B and add 5 cm3 of distilled water to test tube C. Add a few drops of diluted liver extract to test tubes A and C. Add a few drops of distilled water to test tube B. Cap the test tubes loosely with a stopper. Observe the evolution of gas bubbles. Wait for a while to collect enough gas. Test the gas produced in each tube with a glowing splint.

Highlight the actions and what receives the action Grind 10 g of fresh pig liver tissue in a mortar with 10 cm3 of cold distilled water. Filter the ground mixture by using muslin cloth to obtain the liver extract. Dilute the liver extract by adding 5 cm3 of cold distilled water. Label test tubes A to C. Add 5 cm3 of 3% hydrogen peroxide solution to test tubes A and B and add 5 cm3 of distilled water to test tube C. Add a few drops of diluted liver extract to test tubes A and C. Add a few drops of distilled water to test tube B. Cap the test tubes loosely with a stopper. Observe the evolution of gas bubbles. Wait for a while to collect enough gas. Test the gas produced in each tube with a glowing splint.

Writing the procedure in a Lab Report A Lab Report tells us what the scientist (you) did, so the scientist writer uses the past tense in a statement, eg: I heated the test tube. I added a drop of distilled water to a slide. But, because we want to focus on the science and not the scientist, we put the science at the front and the scientist at the back (or leave him out!), eg: The test-tube was heated (by me). A drop of distilled water was added to a slide (by me).

Constructing the passive voice — Example 1 Grind 10 g of fresh pig liver tissue in a mortar with 10 cm3 of cold distilled water. Instruction Active voice ground 10 g of fresh pig liver tissue in a mortar with 10 cm3 of cold distilled water. This says what we did. We Passive voice in a mortar with 10 cm3 of cold distilled water. This says what was done. 10 g of fresh pig liver tissue was ground

Constructing the passive voice — Example 2 Filter the ground mixture by using muslin cloth to obtain the liver extract. Instruction Active voice This says what we did. filtered the ground mixture by using muslin cloth to obtain the liver extract. We Passive voice This says what was done. The ground mixture by using muslin cloth to obtain the liver extract. was filtered

Constructing the passive voice — Example 3 Dilute the liver extract by adding 5 cm3 of cold distilled water. Instruction Active voice diluted the liver extract by adding 5 cm3 of cold distilled water. This says what we did. We Passive voice by adding 5 cm3 of cold distilled water. This says what was done. the liver extract was diluted

Writing the procedure in a Lab Report – Activity 1 Write what was done in these steps of the experiment — write in the past tense and in the passive voice. 4. Label test tubes A to C. _Ans:__________________________________________________________ 5. Add 5 cm3 of 3% hydrogen peroxide solution to test tubes A and B and add 5 cm3 of distilled water to test tube C. 6. Add a few drops of diluted liver extract to test tubes A and C. Test tubes A to C was labeled 5 cm3 of 3% hydrogen peroxide solution was added to test tubes A and B and 5 cm3 of distilled water was added to test tube C. A few drops of diluted liver extract was added to test tubes A and C.

Writing the procedure in a Lab Report – Activity 1 Write the remaining steps of the experiment, telling us what was done. 7. Add a few drops of distilled water to test tube B. _Ans:__________________________________________________________ 8. Cap the test tubes loosely with a stopper. 9. Observe the evolution of gas bubbles. 10. Wait for a while to collect enough gas. _Ans: __________________________________________________________ 11. Test the gas produced in each tube with a glowing splint. A few drops of distilled water was added to test tube B. The test tubes were capped loosely with a stopper. The evolution of gas bubbles was observed. It was waited for a while to collect enough gas. The gas produced was tested in each tube with a glowing splint.

You did it! Well done!