Science lesson plan · 7th grade (Year 8 in England) · 45 minutes
Digestive enzymes and the molecules they make
Human body and health
CCSS NGSS.MS-LS1-3CCSS NGSS.HS-LS1-6England: KS3 Biology: Nutrition and digestionEngland: GCSE Combined Science: Organisation
Objective and success criteria
Students will: Digestive enzymes and the molecules they make.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Trace a meal through the digestive system; Food groups, nutrients and what each one does
Leads to: How enzymes work: active sites, temperature and pH
Materials: Stopwatches, Body diagrams, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Trace a meal through the digestive system; Food groups, nutrients and what each one does). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which nutrient group matches this: iron for making red blood cells? (lipids (fats and oils) / fibre (fiber) / proteins / vitamins and minerals) → vitamins and mineralsPrompt: Energy, growth, stored energy, small amounts for health, or keeping the gut moving?
- Where are most digested food molecules absorbed into the blood? (small intestine / oesophagus (esophagus) / large intestine / stomach) → small intestinePrompt: This organ is lined with millions of villi.
- Which nutrient group matches this: keeps food moving through the intestines? (proteins / carbohydrates / fibre (fiber) / lipids (fats and oils)) → fibre (fiber)Prompt: Energy, growth, stored energy, small amounts for health, or keeping the gut moving?
Hook · 5 min
- Ask everyone to find their pulse, then jump for 30 seconds and find it again.
- Share the objective: Digestive enzymes and the molecules they make. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Which enzyme is described here: breaks fats down into fatty acids and glycerol?
- Step 1: Lipase breaks lipids into fatty acids and glycerol.
- Step 2: So the answer is: lipase
- Answer: lipase
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Which enzyme is described here: breaks fats down into fatty acids and glycerol? (amylase (a carbohydrase) / protease / lipase) → lipasePrompt: The enzyme's name often sounds like the food it breaks down.
- Amylase was mixed with starch at different temperatures. Iodine was used to time how long the starch took to disappear: 20 °C: 10 min 30 °C: 7 min 40 °C: 3 min 50 °C: 7 min 60 °C: starch still present after 20 min At which temperature did amylase work fastest, in °C? → 40 °CPrompt: Fastest means the shortest time.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Which organ makes bile? (gall bladder / stomach / pancreas / liver) → liverPrompt: Bile is stored in one organ but made in another.
- Which enzyme is described here: breaks fats down into fatty acids and glycerol? (amylase (a carbohydrase) / protease / lipase) → lipasePrompt: The enzyme's name often sounds like the food it breaks down.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Trace a meal through the digestive system.
- Use concrete materials: stopwatches.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: How enzymes work: active sites, temperature and pH.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-7.
Free lesson plan from eurekami.com/lesson-plan-builder