Pupil worksheet Key Stage 4 Nitrogen recycling Spread the cards on the desk. Each choose a place to start and place on your counter. Put a tick on your passport to show where you are. Take it in turns to roll the dice and follow the instructions on the card which tells you where to move next. Remember to tick your passport each time if you are in a new compound. Why do we need nitrogen? The winner is the first person to complete their passport. Plants need nitrogen-containing compounds to make vital molecules like amino acids, DNA and chlorophyll. Without a source of nitrogen they would not grow - and we would have no food. You would think that this is not a problem because we are surrounded by nitrogen - the air is made up of around 78% nitrogen gas. But, this is not in a form that plants can use. They rely on bacteria to convert the nitrogen in the air into compounds that they can absorb through their roots. Nitrogen is moved around the environment as it moves from one organism to the next as part of different compounds. This movement is called the nitrogen cycle. Your task You are a nitrogen atom. You will play a game in a group and go on a journey around the environment. You will then use this to build up your version of the nitrogen cycle and answer some questions to check your understanding. Playing the game Get into a group of 3-4. You will need a set of 9 cards, a counter and passport each, a dice and a clock. Build a cycle The nitrogen cycle is a diagram, which shows the movement of nitrogen around the environment. Work in your group and use the cards to create your own nitrogen cycle on a piece of A3 paper. Add arrows to show the movement of nitrogen. Check your understanding Work alone to answer these questions about the nitrogen cycle. 1. Design a table, which shows the names of the four types of bacteria in the nitrogen cycle and their function. 2. Which type of bacteria are seen as being detrimental to food production? Explain why. 3. Some farmers use crop rotation. They will grow legumes and after harvest let the rest of the plant rot down into the soil. Next year they will plant another crop on this field. Explain how this technique will help improve the growth of crops. 4. Is it possible to get nitrogen-fixing bacteria to live in the roots of other crops like wheat? Explain how this will help to increase food production.
Cards 1 Nitrogen gas (N 2 ) in the atmosphere Ammonium (NH 4 + ) in the soil Nitrate (NO 3 - ) in the soil 1 or 2: Get converted to nitrate in a fertiliser via the Haber-Bosch process. 3 or 4: Get taken up by nitrogen-fixing bacteria in a root nodule of a pea plant and converted to amino acid in plant 5 or 6: Converted to ammonium by nitrogen fixing bacteria in the soil. Even number: Converted to nitrate in the soil by nitrifying bacteria. Odd number: Get taken up by plant roots and converted to amino acids in the plant. 1 or 2: Get taken up by plant roots and converted to amino acids in the plant. 3 or 4: Converted to nitrogen gas by denitrifying bacteria and enter the 5 or 6: Get leached into a pond when it rains.
Key Stage 4 - Nitrogen recycling Cards 2 Amino acid in an animal Nitrogen compound in waste Amino acid in a plant Even number: You get excreted as a nitrogen compound in waste. Odd number: The animal you are in dies and you become a nitrogen compound in dead material. Even number: Decomposers (bacteria and fungi) convert you into an ammonium compound in the soil. Odd number: You are collected and made into a fertiliser. Even number: Get eaten by an animal and converted into amino acids in the animal. Odd number: The plant you are in dies and you become a nitrogen compound in dead material.
Cards 3 Nitrogen compound in dead material Nitrate (NO 3 - ) in fertiliser Nitrate (NO 3 - ) in a pond Even number: Decomposers (bacteria and fungi) convert you into an ammonium compound in the soil. Odd number: You are collected and made into a fertiliser. Even number: Converted to nitrogen gas by denitrifying bacteria and enter the Odd number: Get leached into a pond by the rain. Even number: Converted to nitrogen gas by denitrifying bacteria and enter the Odd number: Get taken up by algae in the water and converted to amino acids in the plant.
Passports