NUTRITION

• A life function •When organisms

take in & use nutrients needed

for energy & all life processes

Nutrients •Substances in foods that

provide energy &

materials for life

processes

6 nutrients needed by the body

1.Carbohydrates

Main source of energy

•Simple carbohydrates a.k.a. sugars

•Found in Fruits, honey, milk

•Complex carbohydrates a.k.a. starches & fiber

•Found in Bread, pasta, potatoes

2. Proteins •Replace & repair body cells

•Growth•Made of amino acids

Found in eggs, meat, cheese, milk

3. Lipids •Fats•Provide energy (storage)

•Cushion & support organs

4. Minerals •Use 14 of them•Maintain normal functioning of the body

•Calcium, phosphorus, iodine…

5. Vitamins Maintain normal functioning of the body

6. Water Needed for cells to carry out some chemical reactions

Calorie Measures the amount of

energy in foods

How isenergymeasured

in food?

•Calories•Amount of heat needed to raise 1 kg of water 1°C

TYPES OF NUTRITION

1. Autotrophic Nutrition

Organisms make their own food through the process of photosynthesis

Examples: Plants, Algae

2. Heterotrophic Nutrition

Organisms must ingest materials already made in the environment

Cannot make their own food

4 processes involved in

Heterotrophic nutrition:

1.Ingestion: process of

taking IN food

2.Digestion: breakdown of food

4.Egestion: removal of undigested food

3. Absorption:Process of nutrients being taken into the bloodstream

1. List the six types Nutrients

needed by the body

2. List the four processes involved in

Heterotrophic Nutrition

6 nutrients needed by the body

Types ofDigestion

1. Mechanical Digestion

Large pieces of food are broken down into smaller pieces by the teeth

Increases surface area of food to speed up chemical

digestionMakes food

easier to swallow

When small food particles are broken down

into small molecules called

nutrientsHOW?

Enzymes

2. Chemical Digestion

Ex: Starches broken down into Sugar

Proteins are broken down into amino acids

Called protease

1. Chemical digestion is aided by enzymes.2. Our food only gets broken

down by mechanical digestion.

3.Proteins are used for long term energy storage.

4.Another name for lipids are fats.

5.Enzymes are chemical in the body used to give humans fresh air.

Digestive System also known as the Alimentary canal

•The system is a one way tube

•The system is made of ________

________

Smooth muscle

Function of the digestive system

To breakdown food into nutrients small enough to pass into cells

1. What are enzymes and how do they assist in the digestive process?

2. How does the digestive system assist an organism in maintaining homeostasis? *Adaptation – any special feature that enables an organism to survive in a particular environment

Pathway of Food Through The DigestiveSystem

The oral cavity is responsible for mechanical digestion by the teeth

1. Oral Cavity (mouth)

Did you know… -Your teeth started growing 3 months before you were even born.

-The hardest substance in your body is the enamel on your teeth.

-As you are sitting there listening, more than 100 million germs are swimming, feeding, reproducing, and making waste in the area behind your lips. In your mouth there are more living things than there are people in Australia and Canada combined…

• Contains Saliva from salivary glands

• Saliva is responsible for the chemical digestion of certain foods

• Chemical digestion of carbohydrates by saliva

• Enzyme in saliva is called Amylase

• Digests starch into sugar

2. Epiglottis

• Small flap of tissue • Closes over windpipe

when you swallow• To prevent choking

3. Esophagus

•Connects mouth to stomach

•NO DIGESTION OCCURS IN THE ESOPHAGUS

• Carries out Peristalsis: muscular movement that pushes food through digestive tract

Digestion.mov

1. Explain the difference between chemical and mechanical digestion.

2. Where does digestion begin?

3. What structures in the digestive system produce

saliva?

HW: Handout “digestive system”

4. Stomach

•J-shaped muscular organ•Contains Gastric glands in wall that secrete/release gastric juice

Gastric juice Contains enzymes that chemically digest food

Gastric Juice contains:1. Hydrochloric acid

2. Enzyme: PepsinChemically digests

protein into amino acids

The stomach has a Mucus lining that coats the stomach for protection

The stomach is also responsible for Mechanical digestion by churning and mixing food

5. Small intestine

Average length is 21 feet (4-7 meters)

•Most chemical digestion occurs there•Chemical digestion ends here•ABSORPTION OCCURS HERE

• The small intestine contains Intestinal juice that is released from liver and pancreas

• Contains enzymes

6. Large Intestine

•NO DIGESTION• Reabsorbs water• Forms feces

(undigested food)• Contains bacteria

Appendix attached the lower

portion of the large intestine

• No function

If you squeezed out all of the bacteria that lives in your intestines, you could almost fill

up a coffee mug.

Rectum

• Last part of large intestine

• Stores feces

Where feces is egested out of the body

Anus