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Expanded Unit Map

Physical, Chemical and Energy Changes in Digestion

is about...9

10

Distinguishing

Identify

Illustrating

Energy changes form inside organisms.

There are two kinds of changes in matter

and

What happens in the digestive system…

The digestive system breaks LARGE molecules into _______ molecules

Recognizing

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+

• Food contains _________ energy.

• The digestive system breaks apart food into pieces ( _______change) and breaks those molecules into smaller molecules ( ______ change) still with __________ energy.

• Those molecules fuel the body where the energy becomes _______ and ___________energy or they are stored as _________energy in fat.

__________• • • • • • •

__________• B_________• R_________- With acid- With other kinds of

molecules

• B_______ down• Synthesizing• Molecules Change

A _______ Change

Matter

Anything that…

…has mass

…or takes up space

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Types of Physical Changes

•Only alters the APPEARANCE of the matter•Does NOT alter the chemical composition

EXAMPLES:• Change in shape• Change in size• Change in the state of matter• melting/boiling

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Signs of Chemical Changes

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• Alters the substance so that it is a new substance • The new substance has NEW properties • NOT easily reversible

SIGNS of a Chemical Change:• Unexpected color change • Odor change• Release of heat, light, or sound• Produces gas or water• Forms a solid (precipitate) • NEW substance, with NEW properties

Physical VS ChemicalChanges

Physical Chemical

Compare and contrast physical and chemical changes. If you can, use what we have learned about today and prior knowledge of the concepts you learned in other grades to include in the Venn diagram. Use your Supplementary Notes.

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Test your real world skills!

Gelling up your hair Chemical or Physical?

Baking a cake Chemical or Physical?

Ice in your cup melting Chemical or Physical?

Molecules breaking down in your stomach Chemical or Physical?

Rust on a nail Chemical or Physical?

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The Digestive SystemPurpose:• Breaks down food into

substances that cells can absorb and use in the body.

How is food digested?• Broken down into smaller pieces• Mixed around• Moved through the digestive tract• Chemically broken down from

large molecules of food into smaller molecules of food

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MouthThe mouth is the first stop in the digestive track. It breaks food down physically and chemically.• Physical digestion: teeth grind up food• Chemical digestion: saliva

– Saliva contains amylase, an enzyme that breaks down carbohydrates into sugars.

– For example, some of the potatoes or rice that you eat turns into sugars while still in your mouth! Since the carbohydrate of the potato is turning into a new substance, sugar, this is a chemical change.

• Chewing mixes the food with saliva, from salivary glands around the mouth and face, to make it moist and easy to swallow. Focus Learning Resources

EsophagusThe esophagus (es-off-o-gus) is mostly about moving food (a physical change in place) and also squeezes the food into a ball called a bolus.• Muscular tube• Moves food by waves of muscle

contraction called peristalsis.• These waves change the shape of

the food and pushes it down until the food reaches the stomach

• In your notes, determine whether this is a physical or chemical change. Explain why. Focus Learning Resources

StomachThe stomach is the best known organ in the digestive system. It is primarily responsible for breaking food down with enzymes and acid (chemically), but it also squeezes and squashes food to break it down physically.

• Digests physically AND chemically

• Physically: the stomach is a muscular organ, which contracts and relaxes squeezing the food to help break it down.– In your notes, explain why this kind of change is a physical change.

• Chemically: the stomach lining produces strong digestive juices. – The juices are enzymes. These enzymes begin chemical reactions in the

stomach, which break down and dissolve the food into nutrients.

– Breaks down proteins and fats in the stomach, getting these nutrients ready to be absorbed in the intestines.

– In your notes, explain why this kind of change is a chemical change.Focus Learning Resources

Small IntestineThe small intestine is named for how wide it is, but it is really, really long. In the small intestine the mixture that comes out of the stomach (called chyme) is mixed with bile and enzymes from the accessory organs. These are the last steps to breaking down the food so that the nutrients can be absorbed into the blood.

• Digests proteins, fats, and carbohydrates (a.k.a. everything).

• Enzymes continue to break down the food that has not been completely digested to prepare it for absorption.

• The nutrients are broken down small enough to pass through the lining of the small intestine, and into the blood (diffusion).

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Large Intestine (Colon)The large intestine is wider than the

small intestine but much shorter. Its primary purpose is to take the water and salt out of what is left of the food, then get rid of it.• Absorbs extra nutrients and water• Forms wastes into solid feces• Mostly physical change

Anus• Expels feces GRODY!!

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Accessory Organs• Accessory organs are vital glands to the digestive

system; however, they are not a part of the digestive tract.

• These organs never touch food; instead, these organs secrete substances into the digestive organs that help with the breaking down and absorption of nutrients.

Accessorize!

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Pancreas • Accessory organ of the digestive

system• Produces hormones and performs

other functions not related to the digestive system

• Food does not go through the pancreas

• For the digestive system, the pancreas produces chemicals to help break down macromolecules (large molecules) into smaller ones

• Aids in the small intestine’s chemical change of macromolecules and assists in absorption of nutrients Focus Learning Resources

ENZYMES!!

Liver• Has many functions within the body• In the digestive system, the liver produces

bile. Bile breaks down lipids and regulates the pH of the digestive system.

Gallbladder• Stores bile

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Let’s Review…Physical changes happen in the:• mouth (chewing)• esophagus (pushing a squishing) • stomach (squishing an

churning).• large intestine (moisture

absorbed)

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Chemical changes happen in the:• mouth (saliva)• stomach (acid and enzymes)• small intestine (enzymes and bile)

Key:

@ = Physical $ = Chemical

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Let’s Review…Pancreas• Sits between stomach and

intestines• Produces enzymes (as well as

hormones)

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Liver• Large organ on upper right abdomen• Processes toxins (like alcohol)• Produces bile for digestive system• (chemical that breaks down fat)