Life Science · California Grade 7

MS-LS1-7

Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism.

Clarification statement: Emphasis is on describing that molecules are broken apart and put back together and that in this process, energy is released.

Assessment boundary: Assessment does not include details of the chemical reactions for photosynthesis or respiration.

Source: California Department of Education, NGSS Preferred Integrated Course Model, Grade 7 (accessed 2026-10-18)

Chapters

Chapter 5: Using Stored Energyassesses

The chapter's core product is a student model of cellular respiration and of food-to-body matter flow: Lab 2 rearranges atom tokens from sugar and oxygen into carbon dioxide and water, W4 and W6 ask students to model and explain where the atoms and the energy go, and W9 traces a meal into fuel and building blocks. The assessment boundary excludes details of the reactions, so no task asks for intermediate steps, ATP or enzyme names.

Worksheets (12)

Chapter	Worksheet	Role	How it connects
Ch. 5	W1 · Warm Seeds in a Dark Flask: Where Did the Energy Come From? Phenomenon exploration	supports	Sprouting seeds in a dark, sealed flask warm up, use oxygen and give off carbon dioxide. Noticing this sets up the question the PE answers: how food is rearranged inside an organism to release energy. No model is built yet; this sheet activates the question.
Ch. 5	W2 · Reactant or Product? Fuel or Building Block? Working the Words Vocabulary in action	practice	Students practice the language they will need to build and explain a model of how food is rearranged in an organism: reactant, product, cellular respiration, and the three families of food molecules and their two fates (fuel or building block).
Ch. 5	W3 · Slow Fire: How Scientists Learned That Living Things Burn Their Food Reading with evidence	supports	The passage gives the historical and conceptual background for the idea that food is broken apart and recombined with oxygen to release energy. It builds understanding behind the model students develop in W4 and W9 rather than producing that model itself.
Ch. 5	W4 · From Acorn to Muscle Cell: Reading and Building a Model of Food's Path Diagrams and models	assesses	Part B asks students to develop their own model of how a root cell rearranges sugar into carbon dioxide and water (releasing energy) and into new cell-wall material (growth). The model stays at the level of inputs, outputs and atom conservation; it does not include the steps of the reaction, which the assessment boundary excludes.
Ch. 5	W5 · Oxygen Used by Sprouting Seeds, and Energy per Gram of Food: Two Datasets Data and graphing	practice	Measuring the oxygen that sprouting seeds consume gives quantitative evidence that food is reacting with oxygen to release energy, and comparing energy per gram of carbohydrate, fat and protein supports the idea that different food molecules store different amounts of energy. The sheet builds the data-analysis practice behind the model without building the model.
Ch. 5	W6 · Do Plants Run on Oxygen Too? A Claim-Evidence-Reasoning Case Claim, evidence, reasoning	practice	Students use evidence to argue that producers, like consumers, rearrange sugar and oxygen into carbon dioxide and water to release energy. Writing the argument builds the understanding that the model in the PE applies to every organism, including plants.
Ch. 5	W7 · Fixing Jade's Exit Ticket: Seven Statements About Food, Energy and Matter Error analysis	practice	Diagnosing and repairing wrong ideas about how food is rearranged (energy is released, not created; matter leaves as gases, it does not become energy; plants respire too; breathing is not the reaction) sharpens the model students must describe in the PE.
Ch. 5	W8 · Twelve Clues About Food: An Evidence Jigsaw on Energy and Matter Collaborative investigation	practice	Sorting evidence under claims about energy release, storage and growth gives students the pieces they will assemble into a model of how food is rearranged in an organism; the jigsaw builds the evidence base for that model without yet drawing it.
Ch. 5	W9 · The Antlion's Budget: Dig, Wait, or Move? An Energy Decision Transfer and design	assesses	Students build a model of an antlion larva in which the ants it eats are rearranged into carbon dioxide and water (releasing energy for digging and staying alive) and into stored fat and new body (growth), and they use that model to decide between strategies. The task stays at the level of inputs, outputs and energy accounting, within the assessment boundary.
Ch. 5	W10 · Using Stored Energy: Mastery Check Retrieval and mastery check	assesses	Items 5, 12 and 13 ask students to describe and draw how food is rearranged into new molecules that release energy or build the body, with atoms conserved; the other items check the vocabulary and ideas the model depends on. No item asks for the steps of the reaction.
Ch. 6	W5 · How Much Gets Through? Energy per Level and a Caterpillar's Matter Budget Data and graphing	supports	Part B relies on the earlier idea that food is broken down inside an organism, releasing energy and carbon dioxide; students use that idea to account for matter without writing any chemical reactions.
Ch. 7	W6 · The Vanishing Log: Where Did 9.6 Kilograms Go? Claim, evidence, reasoning	supports	The explanation rests on decomposers breaking food molecules apart and releasing carbon dioxide and water through cellular respiration. The sheet uses that idea as background and does not ask students to model the rearrangement of molecules.

Labs (3)

Chapter	Lab	Role	How it connects
Ch. 5	Lab 1 · The Jar That Warmed Up: What Are the Seeds Doing in the Dark? Evidence-based mystery	assesses	Students use their own observations of a product (carbon dioxide), released energy (warmth) and growth from stored food to build and defend a model of what the seeds are doing. The reaction's details are not asked for, which respects the assessment boundary.
Ch. 5	Lab 2 · Atom Tokens: Taking a Sugar Molecule Apart Without Losing a Piece Physical model	assesses	The bead model is a direct student-built model of the PE's statement: molecules broken apart, atoms put back together into new molecules, energy released. No reaction steps are required, so the assessment boundary is respected.
Ch. 5	Lab 3 · Field Investigation: What Your Body Changes When Your Muscles Work Harder Classroom field investigation	practice	Students collect evidence for the model built in Lab 2: harder work means more sugar reacted with oxygen, more energy released and more carbon dioxide produced. The lab builds the evidence base for the PE's model rather than producing the model itself, so the role is practice.