Digestion & Enzymes

The Digestive System

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The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

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The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

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The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Stomach Food is churned and chemically digested by enzymes

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

?

Stomach Food is churned and chemically digested by enzymes

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Liver Produces bile for the digestion of fats

Stomach Food is churned and chemically digested by enzymes

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Liver Produces bile for the digestion of fats

Stomach Food is churned and chemically digested by enzymes

?

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Liver Produces bile for the digestion of fats

Stomach Food is churned and chemically digested by enzymes

PancreasProduces enzymes to chemically digest food

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Liver Produces bile for the digestion of fats

Stomach Food is churned and chemically digested by enzymes

PancreasProduces enzymes to chemically digest food

?

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Liver Produces bile for the digestion of fats

Stomach Food is churned and chemically digested by enzymes

PancreasProduces enzymes to chemically digest food

Small intestineCompletes chemical digestion and absorbs digested food into the bloodstream

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Liver Produces bile for the digestion of fats

Stomach Food is churned and chemically digested by enzymes

PancreasProduces enzymes to chemically digest food

Small intestineCompletes chemical digestion and absorbs digested food into the bloodstream

?

The Digestive System

MouthPhysical digestion by teeth and chemical digestion by enzymes in saliva (amylase)

OesophagusCarries food from mouth to stomach

Liver Produces bile for the digestion of fats

Stomach Food is churned and chemically digested by enzymes

PancreasProduces enzymes to chemically digest food

Small intestineCompletes chemical digestion and absorbs digested food into the bloodstream

Large IntestineWater is taken back into the bloodstream and undigested food is carried to the anus

Teeth – physically digest food

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Teeth – physically digest food

IncisorCutting food

Teeth – physically digest food

IncisorCutting food

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Teeth – physically digest food

IncisorCutting food

CanineTearing food

Teeth – physically digest food

IncisorCutting food

CanineTearing food

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Teeth – physically digest food

IncisorCutting food

CanineTearing food

PremolarCrushing & grinding food

Teeth – physically digest food

IncisorCutting food

CanineTearing food

PremolarCrushing & grinding food

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Teeth – physically digest food

IncisorCutting food

CanineTearing food

PremolarCrushing & grinding food

MolarCrushing & grinding food

Enzymes

• Enzymes are chemicals found in all cells in the body.

• Enzymes are biological catalysts.

• What is a catalyst?????

SUBSTRATE

Enzymes• Enzymes are chemicals found in all

cells in the body.

• Enzymes are biological catalysts.

• What is a catalyst??A catalyst is a substance that changes the speed of a reaction, but is not used up in the reaction itself.

SUBSTRATE

Enzyme Reaction

Enzyme + Substrate ---> Enzyme + Product

? + ? ---> ? + ?

SUBSTRATE

Enzyme Reaction

Enzyme + Substrate ---> Enzyme + Product

Amylase + ? ---> ? + ?

SUBSTRATE

Enzyme Reaction

Enzyme + Substrate ---> Enzyme + Product

Amylase + Starch ---> ? + ?

SUBSTRATE

Enzyme Reaction

Enzyme + Substrate ---> Enzyme + Product

Amylase + Starch ---> Amylase + ?

SUBSTRATE

Enzyme Reaction

Enzyme + Substrate ---> Enzyme + Product

Amylase + Starch ---> Amylase + Maltose

SUBSTRATE

Testing the Action the Enzyme Amylase on Starch

How is food prepared first?

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Testing the Action the Enzyme Amylase on Starch

How is food prepared first?

•If using a starchy food (for e.g. cracker) grind up food and dissolve in water.

•If using starch solution, no preparation necessary.

Testing the Action the Enzyme Amylase on Starch

How is food prepared first?

•If using a starchy food (for e.g. cracker) grind up food and dissolve in water.

•If using starch solution, no preparation necessary.

At what temperature is the water bath?

???

Testing the Action the Enzyme Amylase on Starch

How is food prepared first?

•If using a starchy food (for e.g. cracker) grind up food and dissolve in water.

•If using starch solution, no preparation necessary.

At what temperature is the water bath?

•37°C (human body temperature)

Testing the Action the Enzyme Amylase on Starch

How is food prepared first?

•If using a starchy food (for e.g. cracker) grind up food and dissolve in water.

•If using starch solution, no preparation necessary.

At what temperature is the water bath?

•37°C (human body temperature)

How long for reaction to occur?

???

Testing the Action the Enzyme Amylase on Starch

How is food prepared first?

•If using a starchy food (for e.g. cracker) grind up food and dissolve in water.

•If using starch solution, no preparation necessary.

At what temperature is the water bath?

•37°C (human body temperature)

How long for reaction to occur?

•Approximately 10 minutes

• Testing for the Substrate: Starch What chemical is used?

???

• Testing for the Substrate: Starch What chemical is used?

Iodine

• Testing for the Substrate: Starch What chemical is used?

Iodine

What colour does it turn if starch present????

• Testing for the Substrate: Starch What chemical is used?

Iodine

What colour does it turn if starch present?Blue-black

• Testing for the Substrate: Starch What chemical is used?

Iodine

What colour does it turn if starch present?Blue-black

• Testing for the Product: Maltose (reducing sugar) How do you test for a reducing sugar????

• Testing for the Substrate: Starch What chemical is used?

Iodine

What colour does it turn if starch present?Blue-black

• Testing for the Product: Maltose (reducing sugar) How do you test for a reducing sugar?Heat with Benedict's solution

• Testing for the Substrate: Starch What chemical is used?

Iodine

What colour does it turn if starch present?Blue-black

• Testing for the Product: Maltose (reducing sugar) How do you test for a reducing sugar?Heat with Benedict’s solutions

What colour does Benedict’s turn if reducing sugar present????

• Testing for the Substrate: Starch What chemical is used?

Iodine

What colour does it turn if starch present?Blue-black

• Testing for the Product: Maltose (reducing sugar) How do you test for a reducing sugar?Heat with Benedict’s solution

What colour does Benedict’s turn if reducing sugar present?Brick Red

What colour will iodine be in test-tube A????

Testing for Starch (the Substrate):

What colour will iodine be in test-tube A?Orange brown – no starch present

Testing for Starch (the Substrate):

What colour will iodine be in test-tube A?Orange brown – no starch present

What colour will iodine be in test-tube B (the control)????

Testing for Starch (the Substrate):

What colour will iodine be in test-tube A?Orange brown – no starch present

What colour will iodine be in test-tube B (the control)?Blue black – starch still present

Testing for Starch (the Substrate):

What colour will Benedict's be in test-tube A????

Testing for a Reducing Sugar, i.e. maltose (the Product):

What colour will Benedict's be in test-tube A?Brick Red – Reducing Sugar Present

Testing for a Reducing Sugar, i.e. maltose (the Product):

What colour will Benedict's be in test-tube A?Brick Red – Reducing Sugar Present

What colour will Benedict's be in test-tube B (the control)????

Testing for a Reducing Sugar, i.e. maltose (the Product):

What colour will Benedict's be in test-tube A?Brick Red – Reducing Sugar Present

What colour will Benedict's be in test-tube B (the control)?Blue – No reducing Sugar Present

Testing for a Reducing Sugar, i.e. maltose (the Product):

What has happened in test-tube A?

???

What has happened in test-tube A?

Amylase has broken down starch into maltose.

What has happened in test-tube A?

Amylase has broken down starch into maltose.

What has happened in test- tube B?

???

What has happened in test-tube A?

Amylase has broken down starch into maltose.

What has happened in test- tube B?

As there was no enzyme present, starch has not been broken down.