Why do plants and animals “eat”?

• To obtain essential nutrientso For making their own structureso Obtain Energy for survivalo Perform life functions

What do plants and animals “eat”?

• Plants eat minerals and make their own food• Autotrophs

• Animals require organic molecules• Heterotrophs

3 Types of Feeding Behaviours

• Filter Feeding– Organism sucks in water combined

with its food (usually alive) and filters out the water, keeping the food

– Can you think of any examples of this type of organism?

– Examples are clams, blue whales, ducks and flamingoes, oysters, mussels, and scallops.

3 Types of Feeding Behaviours

• Fluid Feeding– Organism ingests its food in a liquid

form– Examples are mosquitoes, leeches,

tapeworms and spiders– Spiders inject enzymes into their

captured prey’s body which break down tissues into a liquid form

3 Types of Feeding Behaviours

• Chunk feeding– Organism breaks down larger bits of

food into continuously smaller bits– Most animals, including us, use this

method– Food is broken down in two ways• Mechanically• Chemically

– What is an example of mechanical breakdown?

– What are the main agents in chemical breakdown?

Complete this chart…

Organism Filter Fluid Chunk

Wolf

Vampire Bat

Venus Fly Trap

Lamprey Eel

Pelican

Grasshopper

Wolf

Vampire Bat

Venus Fly Trap

Lamprey Eel

Pelican? Pelican

Grasshopper

Once the food is inside, what happens?

• It needs to be “digested”– That means that it’s broken down into

most basic compounds and elements• Carbohydrates• Proteins• Fats• Minerals• Vitamins• Water• Fibre?

• Why is it broken down, only to be built up again?– It’s kind of like the Star Trek

“transporter”. Nutrients need to be transported across the cell membrane. They have to be small and in solution

There are 5 things we’re going to be

Looking at…

• The digestive tract through with the food travels

• The actual mechanics of passing the food through this tract

• How the food is actually digested• The other players in the process, like

the liver, pancreas and gall bladder• The roles that nutrients, diet and

health play in the process

We’ll be covering all of this and more!

The Digestive Tract

• There are two types of digestive tracts (well, almost)

• The first is used by amoeba, protozoa, paramecium and other single celled organisms– Using a process known as…– Pinocytosis– They just surround it, enclose it in a

vacuole and digest it using enzymes– When they’re done, the vacuole is

simple expelled from the organism– This is called “intracellular

digestion”

The Digestive Tract• The other type of digestive tract is a

little more complicated• It’s called the “Tube Arrangement”• There is an intake at one end

(what’s that called?) and an outlet at the other end (and generally, they’re all called the same thing)

• Sea anenomes and hydra have a “closed tube” system. Food goes in, is digested and comes out the same opening. Aren’t you glad we don’t have this system?

Questions to Consider!

• Does the “plant food” bought at a hardware store really contain food? If not, what does it contain?

• A snail uses a rasping organ to “file” off bits of food from surfaces. What feeder type is it?

• How does some of the food taken in by a chunk feeder eventually start to resemble the food taken in by a fluid feeder?

• Cats have pointed, cutting teeth; cows have flat, grinding teeth. Why do you think humans have teeth that are generally in between these two extremes?

• What kind of feeders are cows?

homework

• Describe how nutrients and digestion provide materials for energy and growth

• List the six nutrients required by heterotrophs

• Describe how plants use nutrients• Describe three feeding types• Describe the tube concept of

digestion