Carbohydrates 101

Overview

In this second lesson of “Nutrient Essentials Unlocked”, students explore the structure of carbohydrates and classify them into monosaccharides, disaccharides and polysaccharides. They will practise using evidence (examples and properties) to differentiate simple and complex carbohydrates.

Learning intentions

• Students will describe carbohydrates as molecules made from carbon, hydrogen and oxygen.
• Students will identify and distinguish monosaccharides, disaccharides and polysaccharides by structure and example.
• Students will explain how “simple vs complex” links to the number of sugar units.
• Students will use key scientific vocabulary accurately in short explanations.

Success criteria

• I can correctly match monosaccharides, disaccharides and polysaccharides to appropriate examples.
• I can explain the difference between simple and complex carbohydrates using sugar-unit language.
• I can justify my classification using molecular structure reasoning (not just memorising).
• I can communicate my thinking clearly in a short written or verbal explanation.

Curriculum links

• Working scientifically: using models to explain scientific ideas and communicating reasoning.
• Biology (nutrition and the role of nutrients): understanding carbohydrates as a key nutrient and relating structure to function.
• Chemistry foundations (molecules and atoms): recognising that organic molecules can be described by components and bonding patterns at an accessible level.
• Specifying, testing and refining ideas: comparing evidence from examples and justifying conclusions.

Lesson structure (60 minutes)

1. 0–5 mins | Starter retrieval + focus Students answer a quick “recall card” prompt: “What is a carbohydrate and where do we find it in foods?” Teacher checks misconceptions and sets the goal: classification by structure.

2. 5–15 mins | Mini-lesson: sugar units Teacher explains carbohydrate types using a simple particulate model:

• monosaccharides = single sugar unit
• disaccharides = two units linked
• polysaccharides = many units linked Students annotate a class diagram and add examples (e.g., glucose, sucrose, starch) into the correct categories.

3. 15–25 mins | Guided practice sorting In pairs, students sort 12 “food labels” into: simple (monosaccharides/disaccharides) and complex (polysaccharides). As they sort, they must also record which category each item belongs to and one sentence of justification using sugar-unit reasoning.

4. 25–35 mins | Table-talk: differentiate with evidence Students complete a short comparison table:

• “Unit count” (1, 2, many)
• “One example”
• “Why this is simple or complex” Teacher circulates and uses targeted questioning: “What tells you this is polysaccharide rather than disaccharide?”

5. 35–45 mins | Dyslexia-friendly reading task (structured) Students read a short, chunked text pack (one carbohydrate type per section) with highlighted headings and sentence frames. They then answer 3 guided questions:

• Which type has many sugar units?
• Which type is formed from two units?
• Give a food example and justify the category.

6. 45–55 mins | Assessment: quick classification + explanation Individual “exit mini-assessment”: students classify 6 unfamiliar carbohydrate examples (presented as cards showing unit count and a named example) and write a 3-sentence explanation for two of them. Teacher collects for formative review against the success criteria.

7. 55–60 mins | Plenary: misconceptions check + next steps Students share one rule they will remember (“simple = fewer units; complex = many units”). Teacher previews Lesson 3: digestion and how structure affects breakdown.

Resources

• 12 “food label” cards with simple data: suggested sugar type and unit count clue
• Class carbohydrate diagram (monosaccharide/disaccharide/polysaccharide with arrows showing unit linking)
• Pair sorting sheet with columns for category and justification sentence frame
• Chunked reading pack (three short sections) with clear headings and highlighted keywords
• Comparison table template (unit count, example, justification)
• Unit-count card set for the exit mini-assessment (6 cards)
• Coloured pens/highlighters for annotation (optional)
• Timer for guided tasks
• Visual vocabulary strip: carbohydrate, sugar unit, monosaccharide, disaccharide, polysaccharide, starch, glucose, sucrose

Assessment

• Formative: teacher observation during sorting and comparison-table work, using prompts tied to unit count and justification.
• Formative: reading-task answers checked for correct category identification and reasoning.
• Summative-for-learning: exit mini-assessment scored against the “I can” success criteria.

Differentiation

• Support (SEN/dyslexia-friendly):
• Provide the reading pack in short chunks with headings and sentence starters (“This is a disaccharide because…”).
• Offer a partially completed comparison table for students who need it.
• Allow oral responses recorded by the teacher for one question.
• Support (language/EAL):
• Display a model sentence frame bank and a category word wall throughout the lesson.
• Use paired talk before writing so students can rehearse vocabulary safely.
• Extension (advanced learners):
• Ask students to explain how the number of linked units could influence digestion speed and why (link structure to biological role at a conceptual level).
• Provide one “challenge card” featuring an ambiguous example and require students to choose the best fit using unit-count evidence.
• Access for all:
• Keep instructions in one place (board) and repeat key steps before starting independent tasks.
• Use colour-coding consistently for categories across activities.