Digestion Practical Work Sheet Amy Barton City and Islington College Student Name: …………………………………………………………………………

Topic Digestion Aims  It provides a practical demonstration of the digestion process – this worksheet helps tease out the understanding of students as they go through the process.  The learners enjoy this practical activity and the worksheet helps them think in practical terms about the steps involved in each process they undertake. Level Level 2 Method PowerPoint slides, with Practical Work Sheets, Health and Safety Requirements and Equipment Requirements. Equipment  Laptop & Projector  The gut bag is a thick plastic bag that mimics the human digestive tract. Students use food and acids to recreate the digestive process, from mastication, chemical and mechanical digestion, to defecation. The gut bag is officially called Digesto-Rama bags and you can get these from Scientific and Chemical Supplies at £20.57 for a pack of two.  Mortar and Pestle, Hydrochloric Acid, Bicarbonate of Soda, Stickers, Chyme, Antacid Pill, Bucket, Benedict's Solution  Hand-outs (ALL Slides to print, apart from Slide 2)  Pens Duration 20 – 30 Minutes

Digestion Practical Work Sheet Read the lab rules and the labels on the chemicals you have been given. Ensure you all have a hand-out and pen, you will be working in a group, all must contribute to the group. Health and Safety Requirements Laboratory coats (buttoned up) Universal Indicator Hydrochloric Acid – Gloves and care required Equipment Requirements Most items are at the front of the class Some equipment will be in the cupboards Pens are needed to write down your results Best used with the ‘gut bag’ this is commercially available

Digestion Practical Work Sheet Use the mortar and pestle to roughly grind your food (use 2 crackers, leave some lumpy bits). Q: What type of digestion does this represent? ………………………………………………………………………………... Q: Where does this happen in our body, name the organs involved? ………………………………………………………………………………...

Digestion Practical Work Sheet Add a small amount of water to the food to make a paste. Pipette in a small amount of the Universal Indicator (this tells you the pH) Add amylase to the mixture and mix it in Q: What is amylase and what does it do to starch? ………………………………………………………………………………... …………………………………………………………………………… Q: Where does amylase act in the digestive system? ………………………………………………………………………………... ……………………………………………………………………………......

Digestion Practical Work Sheet Feed the paste (using the spatula) into the ‘mouth’ of the digestive tract. Use your hands to push the food into the stomach, one student hold the bag upright and another push the food. Q: What is then name of the wave of muscle movement that moves food through the digestive tract? ………………………………………………………………………………... …………………………………………………………………………… Q: What is the name of the tube that links the mouth and the stomach? ………………………………………………………………………………... …………………………………………………………………………… Q: What colour is the food with the Universal Indicator, what pH is this? ………………………………………………………………………………... …………………………………………………………………………… Q: What is the name of the food as it passes into the stomach? ………………………………………………………………………………... ……………………………………………………………………………......

Digestion Practical Work Sheet When the food is in the stomach, add Hydrochloric Acid ***be very careful as this is acidic, do not get it on your skin*** Q: What type of digestion is this? ………………………………………………………………………………... Q: What type of digestion is this? …………………………………………………………………………… Use your hands to churn the food, do this for 5 whole minutes (this this job within the group) Q: What is the food/acid mixture called now? …………………………………………………………………………… Q: What colour is the food/acid Universal Indicator now, what pH is this? …………………………………………………………………………… Now add bicarbonate of soda to the stomach. This should produce some gas Q: What normally happens to gas in the digestive track? …………………………………………………………………………… Now use the stickers to label the digestive tract. Use all of the words you can think of, be careful to use the correct spelling (see your class notes).

Digestion Practical Work Sheet Only after 5 minutes of churning, and finishing all of the tasks, push the chyme into the intestine. Q: What colour is the food/acid/Universal Indicator now? ………………………………………………………………………………... Q: What change do you think has happened to the pH? …………………………………………………………………………… Q: Where does the food you eat undergo a dramatic pH change in your digestive track? …………………………………………………………………………… Q: What organ ensures a pH change after the stomach (think carefully about this answer, use your class notes)? …………………………………………………………………………… Grind up an Antacid pill into a fine powder. Add water and push it into the intestine.

Digestion Practical Work Sheet After you show your tutor your work so far, you can move the food out of the stomach and through the rest of the digestive tract. Share the task of moving the food through the digestive tract Empty the food mixture into a bucket. Place some of the mixture back into the mortar and pestle

Digestion Practical Work Sheet Q: What is the name of the ring of muscle that stops food leaking out of the stomach or rectum? ………………………………………………………………………………... Q: Where does the food move into when it leaves the stomach? ………………………………………………………………………………... Q: Why is it good that you have a very long small and large intestine? ………………………………………………………………………………... Q: Why is it good that indigestible food is stored in the rectum? ………………………………………………………………………………... Add Benedict’s solution to the mix. Q: What colour has it turned? What does this indicate? ………………………………………………………………………………...

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