Fungi There are many types of fungi Different types have different shapes and sizes Yeasts Yeasts used in bread making are tiny unicellular fungi Moulds Moulds which grow readily on stale bread or overripe fruit are made up of many thin threads ID: 423787
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Slide1
FungiSlide2
Fungi
There are many types of fungi.
Different types have different shapes and sizes.Slide3
Yeasts
Yeasts, used in
bread making
are tiny unicellular fungi.Slide4
Moulds
Moulds which grow readily on stale bread or over-ripe fruit are made up of many thin threads.
This gives the mould a fuzzy or furry appearance.Slide5Slide6
Mushrooms and Toadstools
These are larger structures which grow in the soil and humus.Slide7
Structure
A fungus is usually made of many fine threads called
hyphae
and structures called
sporangia
which contain spores.Slide8
Structure
The hyphae spread forming a tangled mat called a
mycelium
(visible to the naked eye.)Slide9
Nutrition
Fungi grow on top of and down through their food source.
They obtain nutrients by releasing
enzymes
which break down the food so that it can be absorbed.
Each type of fungus can only grow on certain substancesE.g. bread mould can not grow on our skin.Slide10
Reproduction
Fungi grow from tiny particles called
spores
, which float in the air like dust.
Each
sporangium contains thousands of spores.Fungal spores can survive for years before they begin to grow.Slide11
Culturing Fungi
Fungi will grow readily in warm, moist places.
Fungi can be cultured on a nutrient agar plate if incubated between 20 – 40
o
C for 3-4 days.Slide12
Helpful Effects of Fungi
Mushroom Farming
Mushrooms are the fleshy fruiting bodies of certain fungi.
The button and flat mushrooms from shops are both
Agaricus
bisporus, the buttons are simply immature fruit while the larger, flat ones are older.Slide13
Helpful Effects of Fungi
Making Bread
The purpose of using yeast is to produce the gas that makes bread rise.
Yeast does this by feeding on the sugars in flour, and expelling carbon dioxide in the process. (Fermentation)
This carbon dioxide forms thousands of balloon-like bubbles in the dough, and the bread rises.Slide14
Helpful Effects of Fungi
Once the bread has baked, this is what gives the loaf its airy texture.Slide15
Helpful Effects of Fungi
Making Alcoholic Beverages
Although there is a distinction between beer and wine, they share one thing in common. They are the fermentation products of
yeasts
.
Fermentation can be summarized as:
Yeast + Glucose Ethanol + CO2Slide16
Helpful Effects of Fungi
Antibiotics
Fungi produce special chemicals which kill or slow the growth of other organisms such as bacteria which would otherwise compete with the fungus for nutrients.
We call these chemicals
antibiotics
.Slide17
Antibiotics
The best known antibiotic is penicillin which is produced by the mould fungus
Penicillium
.
Discovered by Sir Alexander
Flemming in 1928.Penicillin is still important today, but many variations are produced by mutant forms of the fungus. Ampicillin; methicillin, oxacillinSlide18
Antibiotics
Antibiotics attack bacteria in a variety of ways:
Some disrupt the production of the cell wall, preventing the bacteria from reproducing, or causing them to burst open.
Others interfere with protein synthesis, thus arresting bacterial growth.