Chapter_3.pdf - Chapter 3 7 characteristics of living...

Chapter 3 1
Chapter 3
7 characteristics of living things
MRS GREN
living things: animals, plants, micro-organisms, fungi
virus is not a living thing because they only reproduce
Types of microorganisms
algae
photosynthesise
protozoa
feed on smaller micro-
organisms
fungi
have hyphae → a tangle of thin threads
-absorb nutrients from their surroundings
release spores to reproduce
fungi without hyphae = YEAST
-reproduce by budding
bacteria
smallest micro organisms

Chapter 3 2
reproduce by binary fission = splitting in 2
Microscope
Fermentation
sugary solution → alcohol + carbon dioxide
yeast consume the sugar in respiration and produce alcohol inside the liquid
other bacteria in liquid consume sugar in respiration and produce lactic acid
inside the liquid
-these bacteria should be killed to prevent liquids such as milk from going
sour; ensures food is fresh
how we can keep food fresh:
pasteurisation
-heating foods to a certain temperature that kills harmful bacteria
without affecting the flavour
keep in air-tight containers
store in fridges