Middle School Science Quiz: Model Food Breakdown

20 questions · exam conditions

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Model Food BreakdownQuestion 1 of 20

A teacher shows two models of the same food entering an organism.

Model A: Food enters → food breaks into smaller molecules → smaller molecules rearranged into new molecules that become part of the organism. Model B: Food enters → food is shown as the same molecule the whole time → the model labels the end result as "energy only."

Which statement about food breakdown is supported by the evidence in Model A compared with Model B?

Reminder: digestion breaks down and rearranges food molecules.

Digestion is mostly about turning food into energy, so showing molecules after digestion is unnecessary.

Food molecules disappear during digestion, which is why Model B does not show any molecules at the end.

Food molecules are rearranged into new molecules after being broken down, so digestion changes molecules rather than leaving them unchanged.

If a model shows more pieces after digestion, it means the organism created new matter during digestion.

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Middle School Science Quiz

Middle School Science Quiz: Model Food Breakdown

Practice Model Food Breakdown in Middle School Science with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Model Food Breakdown, giving you a quick way to practice the rules, question types, and explanations that matter most for Middle School Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A teacher shows two models of the same food entering an organism.

Which statement about food breakdown is supported by the evidence in Model A compared with Model B?

Reminder: digestion breaks down and rearranges food molecules.

Digestion is mostly about turning food into energy, so showing molecules after digestion is unnecessary.
Food molecules disappear during digestion, which is why Model B does not show any molecules at the end.
Food molecules are rearranged into new molecules after being broken down, so digestion changes molecules rather than leaving them unchanged. (correct answer)
If a model shows more pieces after digestion, it means the organism created new matter during digestion.

Explanation: The core skill in modeling food breakdown is comparing different models to determine which provides better evidence for digestion's effects. Digestion breaks food into smaller molecules, a process that occurs internally to extract usable parts. These are then rearranged into different molecules, not destroyed, for incorporation into the organism. Models highlight this by contrasting initial and final states, showing transformation without loss. A misconception is that digestion primarily produces energy without molecular outcomes, but accurate models include rearranged molecules. Breaking down food renders its materials suitable for cellular processes. Ultimately, this enables organisms to sustain themselves by repurposing food matter.

Question 2

A class is comparing four simplified models of food entering an organism and changing inside it. In all four, the food starts as one large molecule outside the organism.

Which model shows the best evidence that digestion breaks food molecules into smaller molecules and then rearranges them (instead of destroying them), based on a clear before-and-after comparison?

Reminder: digestion breaks down and rearranges food molecules.

Inside the organism, the food is shown as tiny crumbs only, and then the crumbs vanish with an arrow labeled "gone."
Inside the organism, the food is shown turning directly into a lightning-bolt symbol labeled "energy," with no molecules shown afterward.
Inside the organism, the food is shown as several smaller molecules, and later those smaller molecules are shown combined in a new arrangement that becomes part of the organism. (correct answer)
Inside the organism, the food is shown as the same large molecule unchanged, just moving to a different place.

Explanation: The core skill in modeling food breakdown is evaluating models to find the best representation of digestion's effects on molecules. Digestion breaks food into smaller molecules inside the organism, turning large structures into manageable pieces through enzymatic action. These molecules are rearranged, not destroyed, to form new compounds that integrate into the organism's body. Models illustrate this by comparing initial large molecules to subsequent smaller ones that are reorganized, emphasizing conservation of matter. A misconception is that food simply vanishes or turns into energy without molecular changes, but accurate models show ongoing molecular presence. Breaking down food enables cells to rearrange materials for energy and growth. In general, this process makes food's components accessible, allowing organisms to thrive by reusing matter efficiently.

Question 3

A student draws a model of what happens to a bite of food. The model shows: (1) a piece of food entering an organism, (2) the food being broken down into smaller pieces inside, and (3) the smaller pieces being rearranged into new molecules that become part of the organism. Which statement about food breakdown is supported by the model and its before-and-after comparison, using evidence from what is shown?

Reminder: digestion breaks down and rearranges food molecules.

Digestion breaks food into smaller molecules and rearranges them into different molecules that can become part of the organism. (correct answer)
Food stays the same molecules; it only changes location as it moves through the organism.
Digestion mainly turns food into energy, so the molecules do not matter after the food is eaten.
Food molecules disappear after digestion, so there is less matter inside the organism.

Explanation: The core skill in modeling food breakdown is understanding how digestion transforms food into usable materials for an organism. Digestion breaks food into smaller molecules by separating the large molecules in food through chemical processes in the digestive system. These smaller molecules are then rearranged into new molecules that the organism can use, rather than being destroyed or lost. Models show this change by illustrating a before-and-after comparison, where large food molecules enter and are depicted as broken down and reorganized into body molecules. A common misconception is that food disappears after digestion, but actually, the matter is conserved and transformed. Breaking down food into smaller molecules allows cells to access and utilize these building blocks for growth and repair. Ultimately, this process ensures that the materials from food become integrated into the organism's structure, supporting its survival and function.

Question 4

A model shows a piece of food entering an organism. Inside, the model shows the food first broken into smaller molecules. Next, it shows those smaller molecules rearranged into molecules that become part of the organism's body. Which prediction about breakdown is supported by the model if the food were not broken down into smaller molecules?

Reminder: digestion breaks down and rearranges food molecules.

It would be harder for the organism to rearrange the food into new molecules, because the model shows rearrangement happening after smaller molecules are made. (correct answer)
Nothing would change except the food would provide less energy, since digestion is only about energy.
The food molecules would disappear, because breakdown is what keeps matter from vanishing.
The food molecules would still be rearranged into new body molecules without needing to be broken down first.

Explanation: The core skill in modeling food breakdown is making predictions based on models about what happens if digestion steps are altered. Digestion breaks food into smaller molecules, a crucial step for further processing inside the organism. These molecules are then rearranged into usable forms, not destroyed, to build body structures. Models show this by depicting sequential changes, from breakdown to rearrangement, highlighting dependencies. A misconception is that breakdown is unnecessary for rearrangement, but models indicate it's foundational. Breaking down food ensures materials are in a form cells can manipulate. Generally, this enables organisms to efficiently use food for growth and energy needs.

Question 5

Two students make before-and-after models of the same snack entering an organism.

Model 1: A large food molecule enters the organism. Inside, it is shown as several smaller molecules. Later, those smaller molecules are shown connected in a new arrangement that becomes part of the organism.

Model 2: A large food molecule enters the organism. Inside, it is shown as the same large molecule, only drawn smaller. Later, it is shown as "energy" with no molecules shown.

Which claim about digestion is incorrect based on the evidence in the models and the idea that digestion breaks down and rearranges food molecules?

Digestion can break food into smaller molecules inside the organism.
Food molecules can be rearranged into different molecules that become part of the organism.
Digestion makes the food molecules disappear completely, so no molecules remain after digestion. (correct answer)
A before-and-after model can show that the molecules are changed, not just moved.

Explanation: The core skill in modeling food breakdown is using evidence from models to identify correct and incorrect claims about digestion. Digestion breaks food into smaller molecules, enabling the body to process complex foods like snacks into simpler components. Importantly, these molecules are rearranged into new forms that become part of the organism, not destroyed, preserving the matter. Models demonstrate this by showing before-and-after states, where molecules are broken down and then reconfigured, providing evidence of transformation. One misconception is that digestion makes molecules vanish into energy, but models reveal they persist in new arrangements. Breaking down food makes its materials usable by cells for building tissues and performing functions. This generalization highlights how digestion supports the organism's ability to grow and maintain itself using ingested matter.

Question 6

A student is checking a classmate's model for errors. The classmate's model shows: food entering an organism; the food breaking into smaller molecules; then an arrow labeled "digestion" pointing to an empty space with the label "molecules destroyed."

Which claim about digestion is incorrect, based on the model idea that digestion breaks down and rearranges food molecules and the evidence needed in a before-and-after comparison?

Digestion breaks food into smaller molecules inside the organism.
Digestion rearranges smaller molecules into different molecules that can become part of the organism.
Digestion destroys the food molecules so they no longer exist as matter inside the organism. (correct answer)
A model should show what happens before and after digestion to provide evidence of change.

Explanation: The core skill in modeling food breakdown is checking models for errors and identifying incorrect claims about digestion. Digestion breaks food into smaller molecules, using enzymes to disassemble food structures. Crucially, these molecules are rearranged, not destroyed, to form new substances within the organism. Models should show before-and-after comparisons to provide evidence of this non-destructive change. A misconception is that digestion eliminates molecules entirely, but proper models reveal their persistence. Breaking down food prepares materials for cellular rearrangement and use. In essence, this process makes food's matter functional for the organism's ongoing needs.

Question 7

A student says: "When food is digested, it is destroyed, so it no longer exists as matter." Another student points to a model that shows food entering an organism, being broken into smaller molecules, and then those smaller molecules being rearranged into new molecules that become part of the organism.

Which statement about food breakdown is supported by the model as evidence against the first student's claim?

Reminder: digestion breaks down and rearranges food molecules.

Digestion destroys matter, which is why the organism must keep eating to replace lost matter.
Digestion breaks food molecules into smaller molecules and rearranges them into different molecules, so the matter is changed but not destroyed. (correct answer)
Digestion only happens during chewing, so once food is swallowed it stays the same molecules.
Digestion changes food into energy only, so molecules are not part of the outcome.

Explanation: The core skill in modeling food breakdown is using models as evidence to counter incorrect claims about digestion destroying matter. Digestion breaks food into smaller molecules, chemically dismantling large food structures within the body. However, these molecules are rearranged into new ones, not destroyed, maintaining the total matter. Models convey this by illustrating food's transformation from entry to integration, with clear before-and-after visuals. A misconception is that digested food ceases to exist, but evidence shows it's repurposed. Breaking down food allows cells to access and reorganize materials for essential functions. This process generalizes that digestion converts food into cellular building blocks, sustaining life.

Question 8

A student made a simplified before-and-after model of digestion:

Before: A large food molecule enters an organism. After: The model shows many smaller molecules inside the organism, and later shows those same smaller molecules rearranged into a new molecule labeled "part of the organism."

Which statement about food breakdown is supported by the evidence in this model?

Reminder: digestion breaks down and rearranges food molecules.

Food molecules are rearranged into new molecules that can become part of the organism after they are broken into smaller molecules. (correct answer)
Food molecules stay unchanged; the model only shows them spread out in different places.
Food becomes smaller only because it is chewed, so the inside of the organism does not change molecules.
The model proves the organism creates new matter during digestion because there are more molecules after than before.

Explanation: The core skill in modeling food breakdown is interpreting simplified before-and-after models to support statements about molecular changes. Digestion breaks food into smaller molecules, simplifying complex foods into basic units through bodily processes. These units are rearranged into new molecules that become part of the organism, conserving matter rather than destroying it. Models represent this by showing large molecules transforming into smaller ones that are reorganized. A misconception is that digestion creates new matter, but models demonstrate it's just reconfiguration. Breaking down food makes its components available for cellular use. This underscores how digestion allows organisms to incorporate external materials into their bodies.

Question 9

A diagram model is shown below.

It shows: (1) a food molecule entering an organism, (2) the food molecule becoming several smaller molecules inside, and (3) those smaller molecules rearranged into a different molecule labeled "new body molecule."

Which statement about food breakdown is supported by the model and its evidence from before-and-after changes?

Reminder: digestion breaks down and rearranges food molecules.

The model shows food being broken down into smaller molecules and rearranged into new molecules, so the matter is changed but not destroyed. (correct answer)
The model shows digestion is only chewing, because the food changes size before it enters the organism.
The model shows the food molecules are unchanged; they only look different because the drawing style changes.
The model shows the organism creates extra matter during digestion because there are more pieces drawn after.

Explanation: The core skill in modeling food breakdown is analyzing diagram models to support statements using before-and-after evidence. Digestion breaks food into smaller molecules, facilitating their absorption and use in the body. These molecules are rearranged into new forms, not destroyed, to contribute to the organism's structure. Models illustrate this through visuals of entry, breakdown, and reconfiguration into body molecules. A misconception is that models showing more pieces indicate matter creation, but it's merely division and rearrangement. Breaking down food allows cells to access nutrients effectively. This general principle shows how digestion transforms food into vital cellular resources.

Question 10

A student says: "In digestion, food is broken down and rearranged into smaller molecules that can be used to build new molecules in the organism." Another student says: "Food is broken down, but it is not rearranged."

A simplified model shows: Food enters → smaller molecules form → those smaller molecules become parts of new molecules.

Which statement about food breakdown is supported by evidence in the model?

Digestion breaks down food, and the smaller molecules can be rearranged to form new molecules in the organism. (correct answer)
Digestion only makes food smaller, but the molecules stay the same and are never rearranged.
Digestion happens only in the stomach, so rearrangement cannot occur anywhere else.
Digestion creates new matter from nothing when it rearranges molecules.

Explanation: The core skill is evaluating statements about food breakdown using evidence from digestion models. Digestion breaks food into smaller molecules via enzymatic reactions that target specific bonds. The resulting pieces are rearranged into new molecules, preserving all matter without destruction. Models depict this by illustrating the transition from complex food molecules to simpler ones and their subsequent recombination. People often mistakenly think digestion doesn't involve rearrangement, but it does to create body-specific compounds. Breaking down food supplies cells with raw materials for synthesis and repair. In this way, food materials become usable by cells to maintain health and function.

Question 11

A model shows a large food molecule entering an organism. Inside, it becomes several smaller molecules. Later, some smaller molecules are shown as parts of new molecules in the organism.

Which statement about food breakdown is supported by evidence from the model's before-and-after comparison?

The food molecules are broken down into smaller molecules and then rearranged into new molecules; the matter is not destroyed. (correct answer)
The food molecules are unchanged; only their location changes as they move through the organism.
The molecules shown after digestion are created from nothing, because the original food molecule is gone.
The model must be taken literally, so the organism contains exactly the same shapes as the drawing.

Explanation: The core skill is interpreting before-and-after comparisons in models to support statements about food breakdown. Digestion breaks food into smaller molecules using acids and enzymes in the digestive system. The molecules are rearranged without being destroyed, maintaining the conservation of matter. Models convey this change by showing the disassembly of food and the formation of new molecular arrangements. One misconception is that food molecules remain unchanged or are created from nothing, but they are transformed from existing matter. Breaking down food enables cells to repurpose the materials for various functions. This makes ingested food usable by cells for repair, growth, and energy production.

Question 12

A student tries to summarize a model of digestion with a before-and-after comparison.

Before: Food molecules enter an organism. After: Smaller molecules are present, and some are rearranged into new molecules.

Which statement about food breakdown is supported by evidence from this model?

Digestion happens only in one organ, so the model is wrong if it shows changes happening in more than one place.
Digestion keeps food molecules unchanged; the organism only stores them as they are.
Digestion makes food turn directly into energy, so the matter no longer exists after digestion.
Digestion breaks down and rearranges food molecules into smaller molecules that can be used to form new molecules. (correct answer)

Explanation: The core skill is summarizing digestion models to support accurate statements about food breakdown. Digestion breaks food into smaller molecules that the body can process and absorb. These molecules are rearranged into new forms without any loss of matter. Models demonstrate this through comparisons of initial and final molecular states. One misconception is that food turns directly into energy without remaining as matter, but it is conserved and transformed. Breaking down food ensures cells receive nutrients in a usable format. Overall, this makes dietary materials accessible for cellular use in growth and metabolism.

Question 13

A student says: "Digestion breaks down food, so the food molecules are gone afterward." Another student says: "Digestion breaks down food into smaller molecules, and those molecules can be rearranged into new molecules."

Which claim about digestion is incorrect, based on the idea that digestion breaks down and rearranges food molecules?

The first student's claim is incorrect because digestion does not make molecules disappear; it breaks them down and rearranges them. (correct answer)
The second student's claim is incorrect because digestion cannot make smaller molecules.
Both claims are incorrect because digestion only changes the size of food pieces, not molecules.
Neither claim can be evaluated because digestion is too random to model with before-and-after evidence.

Explanation: This question identifies misconceptions about modeling food breakdown during digestion. Digestion breaks down large food molecules into smaller molecules through chemical processes, not physical crushing alone. These smaller molecules retain all their atoms—matter is conserved, not destroyed or made to disappear. The first student's claim that molecules are "gone" represents a common misconception about matter conservation during chemical changes. The second student correctly describes how smaller molecules can be rearranged into new molecular structures. Models of digestion must show this conservation of matter principle. Understanding that digestion rearranges atoms rather than destroying them explains how organisms transform food into usable cellular materials.

Question 14

Two students describe what happens to food during digestion.

Student 1: "Food is broken down into smaller molecules, and the smaller molecules can be rearranged to build parts of the organism." Student 2: "Food is destroyed in the stomach, so the original molecules are gone."

Which claim about digestion is incorrect, based on the idea that digestion breaks down and rearranges food molecules (not destroys them)?

Both claims are correct because digestion can both destroy molecules and rearrange them at the same time.
Neither claim can be evaluated because models cannot provide evidence about what happens to molecules.
Student 1's claim is incorrect because digestion only makes food smaller; it cannot rearrange molecules into new ones.
Student 2's claim is incorrect because digestion breaks down and rearranges food molecules; they are not destroyed. (correct answer)

Explanation: This question focuses on identifying misconceptions about modeling food breakdown. Digestion involves breaking large food molecules into smaller component molecules through enzymatic action. These smaller molecules retain their atoms but can be rearranged into new molecular structures that the organism needs. Models of digestion should show this conservation of matter—atoms are neither created nor destroyed. Student 2's claim that molecules are "destroyed" represents a common misconception that confuses breaking molecular bonds with eliminating matter entirely. Student 1 correctly describes the process where breakdown enables rearrangement. Understanding that digestion reorganizes matter rather than destroying it helps explain how organisms convert food into body structures.

Question 15

A model shows: a caterpillar eats a leaf → leaf molecules are broken down into smaller molecules → the smaller molecules are rearranged into molecules that become part of the caterpillar.

Which prediction is supported if the breakdown step does not occur (the leaf molecules are not broken into smaller molecules)? Use the model and evidence about before-and-after changes.

The caterpillar would still be able to rearrange the leaf molecules into body molecules even without breaking them down first.
The leaf molecules would disappear, so the caterpillar would lose matter from its body.
Fewer smaller molecules would be available to rearrange, so making new body molecules would be harder for the caterpillar. (correct answer)
Nothing would change because digestion only moves food through the body and does not change molecules.

Explanation: This question explores predictions about food breakdown using model evidence. During normal digestion, large food molecules must first be broken down into smaller component molecules before they can be rearranged into new structures. If breakdown doesn't occur, the large intact molecules would be too complex to rearrange efficiently into the specific molecules the caterpillar needs. The model supports that fewer usable building blocks would be available, making it harder to construct new body molecules. A misconception is that rearrangement can happen without breakdown, but large molecules must be disassembled first. This two-step process of breakdown then rearrangement allows organisms to convert various foods into the precise molecules their cells require for growth and function.

Question 16

A student is checking a classmate's model of digestion:

Before: a piece of pasta enters a lizard. During: the pasta is shown as smaller molecules. After: the lizard has "new body molecules," but the model shows no connection between the smaller molecules and the new body molecules.

Which change would best fix the model so it shows evidence that digestion breaks down and rearranges food molecules (not destroys them)?

Add arrows showing the smaller molecules being rearranged into the new body molecules after digestion. (correct answer)
Remove the smaller molecules so it looks like the pasta disappears during digestion.
Label the pasta "energy" after it enters so the model shows the main result of digestion is energy only.
Show the pasta staying exactly the same molecules before and after to keep the model simple.

Explanation: This question addresses improving models to show food breakdown and molecular rearrangement. Effective digestion models must show both breakdown of food molecules into smaller molecules and their subsequent rearrangement into new body molecules. The current model shows breakdown but fails to connect the smaller molecules to the new body molecules, leaving the rearrangement step unclear. Adding arrows to show smaller molecules being rearranged would complete the model by demonstrating conservation of matter. A misconception is that food disappears or turns only into energy during digestion, but atoms are conserved and reorganized. Showing the connection between breakdown products and new molecules helps students understand how organisms convert food materials into usable cellular components.

Question 17

A model shows: (Before) a fish eats a pellet of food. (During) the pellet is broken down into many smaller molecules. (After) those smaller molecules are rearranged into molecules found in fish muscle.

Which statement is supported by the model and its before-and-after evidence?

The pellet molecules are destroyed and replaced by new molecules made from nothing inside the fish.
All digestion happens only in the fish's stomach, so the model must show a stomach label to be correct.
Only the pellet's size changes; the molecules stay the same because digestion is just crushing.
The pellet molecules are broken down into smaller molecules and rearranged into new molecules in the fish's body. (correct answer)

Explanation: This question evaluates understanding of food breakdown models showing molecular changes. During digestion, food molecules undergo chemical breakdown into smaller component molecules. These smaller molecules can then be rearranged and combined differently to form new molecules that become part of the organism's tissues, like muscle proteins. The model correctly shows pellet molecules being broken down and rearranged into fish muscle molecules. A misconception is that molecules are destroyed and replaced by new ones from nothing, violating conservation of matter. The location of digestion (stomach mention) is less important than showing the molecular changes. This breakdown and rearrangement process allows organisms to convert any food into the specific molecules their cells need.

Question 18

A simplified model shows: a grape enters a worm → the grape molecules are broken down into smaller molecules → the smaller molecules are rearranged into molecules that help the worm grow.

Which statement about food breakdown is supported by this model's evidence?

The grape molecules are broken down into smaller molecules, and those smaller molecules are rearranged into molecules used by the worm. (correct answer)
The grape molecules stay unchanged; digestion only moves them through the worm.
The grape molecules are turned into energy only, so no matter from the grape remains in the worm.
The grape molecules are destroyed during digestion, so the worm's body matter is created from nothing.

Explanation: This question assesses understanding of how models represent food breakdown at the molecular level. During digestion, food molecules are broken down into smaller component molecules through chemical reactions. These smaller molecules serve as building blocks that can be rearranged into new molecular structures the organism needs for growth and maintenance. The model correctly shows grape molecules being broken down and then rearranged into molecules used by the worm. A misconception is that food turns directly into energy with no matter remaining, but energy release is separate from molecular rearrangement. The breakdown of food molecules into smaller units allows organisms to rebuild them into the specific molecules their cells require for structure and function.

Question 19

A student draws two models of what happens after a piece of bread enters a human:

Model X: Bread enters → bread breaks into smaller molecules → smaller molecules are rearranged into molecules that become part of the body. Model Y: Bread enters → bread is chewed into smaller crumbs → crumbs stay the same molecules and leave the body unchanged.

Which model shows digestion as breaking down and rearranging food molecules, based on the evidence in the before-and-after steps?

Model Y, because it shows the bread getting smaller.
Neither model, because digestion only happens in the stomach and the models do not label the stomach.
Model X, because it shows food molecules broken down and rearranged into new molecules in the body. (correct answer)
Both models, because any size change means molecules were rearranged.

Explanation: This question tests the ability to evaluate models of food breakdown based on molecular changes. Digestion breaks down large food molecules into smaller molecules through chemical processes in the digestive system. These smaller molecules can then be rearranged into new molecular structures that become part of the organism's body. Model X correctly shows this sequence: breakdown followed by rearrangement into body molecules. Model Y only shows physical size reduction (chewing) without molecular change, which is incomplete. A common misconception is that any size change represents digestion, but true digestion requires chemical breakdown at the molecular level. This molecular breakdown and rearrangement enables organisms to convert diverse foods into the specific molecules their cells require.

Question 20

A student predicts what would happen if breakdown does not occur in an organism. In a correct model, digestion breaks down and rearranges food molecules into smaller molecules the organism can use.

Which prediction about breakdown is supported by this model?

If breakdown does not occur, large food molecules would remain and fewer usable smaller molecules would be available for the organism. (correct answer)
If breakdown does not occur, the food would still rearrange into new molecules because rearrangement happens randomly.
If breakdown does not occur, the food would turn directly into energy and no molecules would be needed.
If breakdown does not occur, the organism would create new matter to replace the missing smaller molecules.

Explanation: The skill of modeling food breakdown includes predicting consequences when digestion processes fail. During normal digestion, large food molecules are broken down into smaller molecules that can be absorbed and used by cells. Without breakdown, large food molecules would remain intact and unable to pass through cell membranes or be rearranged into needed molecules. Models should show that breakdown is essential for making nutrients available to the organism. The misconception that organisms can create new matter or that food turns directly into energy ignores the requirement for molecular breakdown. Breaking down food is necessary to provide the small molecules that cells can absorb and use for building materials and energy.