Can you sort out the statements into True and False?

Carbohydrates, proteins and fats are all made up of carbon, hydrogen, nitrogen and oxygen.

Starch is a large carbohydrate molecule

Fats are made up of smaller units called amino acids

Proteins are made up of one or more glucose molecules

Starch molecules can be broken down by amylase.

Proteins are important for the growth and repair of cells

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Parts of The Alimentary Canal

The alimentary canal (or gut) is the tube within the body through which food passes and is processed in various ways

o moutho oesophaguso stomacho small intestineo large intestineo anus

mouth

salivary glands

oesophagus

liver

stomachpancreas

large intestine

small intestine

anus

Human digestive system

They are special proteins that behave as catalysts, i.e., they accelerate each and every chemical reaction in your body; otherwise, those chemical reactions wouldn't take place, or would do at a very slow pace. Enzymes are very specific and each one can catalise only one chemical reaction: for instance, the only thing that salivary amylase can do is breaking the starch into maltose.

Enzymes

Role of the Mouth

Salivary gland

Salivary gland

Salivary gland

Saliva is mixed with food during chewing

Teeth assist the mechanical breakdown of food

Saliva contains the enzyme amylase which starts the digestion of food

Saliva contains mucus that keeps the mouth moist and lubricates food for easier swallowing

Muscles of the Alimentary Canal Food has to be kept moving along the

alimentary canal whilst being mixed with various juices

These actions are brought about by muscles in the walls of the canal over which a person has little or no conscious control

Peristalsis

The squeezing action of muscles that is used to move food along the alimentary canal

Peri1.spl

• Peristalsis-1

• Peristalsis-2

Digestive Enzymes

What do the following enzymes breakdown?

What do they break the large moleculs down into?

Amlyases Lipases Proteases

Sites of production of main digestive juices

Site of digestive juice production

Main digestive juice produced

Mouth Saliva

Stomach Gastric juice

Liver Bile (breaks down big fat droplets into little fat droplets

Pancreas Pancreatic juice

Small Intestine Intestinal juice

Digestion and Digestive Juices

Saliva

PANCREATIC JUICE

GASTRIC JUICEBile

INTESTINAL JUICE

Digestion and Digestive Juices

SALIVA

•Salivary amylase

•Mucus

PANCREATIC JUICE

•Pancreatic lipase

•Trypsin

GASTRIC JUICE

•Hydrochloric acid

•Pepsin (protease)

•Rennin

•Mucus

Bile

INTESTINAL JUICE

Proteases, Lipases, amylase

In the Mouth…

Starch maltose

Broken down into glucose later by other amylases

Salivary amylase

Types of Teeth

1.Incisor 2. Canine 3. Premolar 4. Molar

Tongue

The tongue is a muscle on the floor of the mouth that manipulates food for chewing and swallowing (deglutition). It is the primary organ of taste, as much of the upper surface of the tongue is covered in papillae and taste buds.

Taste regions of tongue

Taste buds of tongue

Swallowing of bolus

Section of stomach

In the stomach

Protein peptides

Broken down into amino acids later by other proteases

pepsin

Chyme

The fluid food mass that is produced in the stomach when the bolus undergoes a second digestive stage.

Functions of liver

There are many functions of the liver. Some of the most important are:

1.                The production of bile

2.                Detoxifying the body, i.e. breaking down alcohol and drugs

3.                Breaking down excess amino acids to form urea

4.                Converting glucose to glycogen for storage

5.                Converting excess carbohydrates to fats

6.                Storing vitamins

7.                Storing minerals such as Iron, Copper, and Zinc.

8.                Making plasma proteins such as fibrinogen which is used in blood clotting

9.                Making cholesterol which is used to form many hormones

10.           Producing heat for the blood and body

Liver Facts

• Weighs about 1 pound.• Carries out 1000s of functions per day.• Effects the emotions.• Cleanses the blood.• Helps regulate blood sugar.• Metabolizes fats.• Synthesizes vitamin A.• Breaks down toxic substances.• Stores iron for the body.• Stores glycogen (converted glucose).• Metabolizes carbohydrates.• Metabolizes proteins.

Position of Liver

Bile One of the five digestive juices. It is

produced by the liver, stored in the gall-bladder, and it is greenish. It is necessary mostly not to carry digestive enzymes to the duodenum, but to transport bile salts to the duodenum. The bile salts are necessary to help the lipids to "dissolve" in the chyle, forming small droplets, easy to be attacked by the lipases. This process is called emulsification.

Small Intestine

Duodenum

Gall bladder

Hepatopancreatic duct

Bile

Jejunum

Intestinal glands

Composition of BileConstituent

pH

Na+

K+

Ca2+

Cl-

HCO3-

Phosphorus

Bile acids

fatty acids

Bilirubin

Phospholipids

Cholesterol

Proteins

In the pancreas….

Fats fatty acids and glycerolPancreatic lipase

After all the digestive enzymes have done their work…

Glucose

Amino acids

Fatty acids

Glycerol

Finish the sentence….

Something new I learnt today was…..

Something I found difficult to understand was…

The thing I need to revise from today’s lesson is…