How can a fungus digest food without a digestive system?

Digesting OUTSIDE the Body• Fungi can break down polymers (large organic

molecules) OUTSIDE their bodies• The cells in the hyphae send out digestive

enzymes that break the polymer into monomers (small organic molecules)

• The small monomers then can enter the cells of the hyphae and travel through the mycelium

Decomposers use food in two ways

3

Food Digestion

Materialsfor growth:

Biosynthesis

Energy:Cellular

respiration

Where are atoms moving from?

Where are atoms moving to?

The Movement Question

Which atoms and molecules move during digestion and biosynthesis?

amino acids

protein

amino acids

protein

How do amino acids and protein move during digestion?

What happens inside the fungus cell during biosynthesis?

Chemical change

8

Organic moleculesLARGE = Polymer SMALL = Monomers

STARCH

GLUCOSE (SUGAR)

9

Comparing molecules in dead stuff fungi eat

LIPIDS (FAT)

STARCH

PROTEIN CELLULOSE (FIBER)

GLUCOSE (SUGAR)

10

Food (dead stuff) polymers (large organic molecules)

LIPIDS (FAT) = 3 fatty acid monomers and 1 glycerol

PROTEIN = 5 amino acid monomers

CELLULOSE (FIBER) = 6 glucose monomers

STARCH = 6 glucose monomers

11

Food molecules are dead

things like stumps

Place large food

molecules (dead stuff)

here in trunk

12

Food is digested by

fungal enzymes

outside the fungi’s body

Get ready to digest the

food molecules

here

13

Breakdown Food Molecules (Digestion)

Let’s focus on what happens to PROTEIN in food for fungi (dead stuff).(Put the other food molecules to the side of the poster for now.)

Digest PROTEIN molecules by breaking the protein into individual amino acids.

Chemical change

14

Breakdown Food Molecules (Digestion)

Digest STARCH molecules by breaking the starch into individual glucose monomers.

Chemical change

15

Breakdown Food Molecules (Digestion)

Digest FAT molecules by breaking the fat into individual fatty acid and glycerol monomers.

Chemical change

16

Breakdown Food Molecules (Digestion)

Digest FIBER molecules by breaking the cellulose into individual glucose monomers.

Chemical change

17

Move the small

molecules through the

fungal hyphae

Small molecules are taken up and

transported by fungal hyphae

18

Digested Monomers: where do they go?

glucose

glycerol amino acid

fatty acid

19

Build large molecules

here

Biosynthesis is the process of small organic molecules becoming large organic molecules in all body parts

20

What’s in a fungi (mushroom)?PROTEIN

FIBER

Mushrooms

21

Build a mushroom (Biosynthesis)Build PROTEIN molecules by linking 5 amino acid monomers.

Chemical change

22

Build mushroom (Biosynthesis)Build FIBER molecules by linking 5 glucose monomers.

Chemical change

23

What happens to food monomers that are not used in biosynthesis?

24

Identify chemical energy at an atomic molecular scale:

Which molecules have chemical energy?Food

molecules:

Mushroom polymer

molecules:

Fungi food, dead stuff (tree trunk):

Digested monomers in mushroom’s

body:

Example: FAT

Example: AMINO ACID

Example: PROTEIN

Example:CARBOHYDRATES