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iGCSE Life Processes - Coggle Diagram
iGCSE Life Processes
Organisms
8 life processes
Require Nutrition
Respire
Excrete
Move
Respond to stimuli
Reproduce
Grow & develop
Control internal conditions
CELLS
Plant Cells
Chloroplasts
Perform Photosynthesis
which creates...
Cellulose
cannot be digested by humans
but is dietary fibre
starch
storage molecule
not soluble
polymer of glucose
long chains joined together
can be digested by humans
sucrose
contain
chlorophyll
Permanent
Vacuoles
Contain sap and dissolved substances
Cell walls (
permeable
)
Stiff surround to keep cell shape
Cell Components
=
organelles
Nucleus
Control operations of the cell
Chromosomes
Genes
create
proteins
Enzymes
Affected by Temperature & pH
denatured
if temp too high
permanent
Act on molecules called
substrates
Substrates fit perfectly into areas on
the surface of the enzyme called the
active site
Lowers energy for reaction to start:
products formed more easily
Substrate attaches, reaction takes place
products are formed
'lock and key'
model of enzyme action
1 enzyme = 1 reaction
Catalyse reactions within cells
which otherwise would be too cold
and slow
assembled on
ribosomes
Cytoplasm
Liquid in which cell reactions take place
Cell membrane
(
partially permeable
)
Membrane which contains the components of the cell
also
selectively permeable
Mitochondria
Performs
respiration
groups of cells =
tissues
groups of tissues
with particular function
=
organ
organs working together
=
organ system
digestive
gas exchange
circulatory
excretory
nervous
endocrine
reproductive
Energy
aerobic
respiration
using Oxygen
Glucose + Oxygen = Carbon Dioxide + Water + Energy
C6H12O6 + 6O2 = 6CO2 + 6H2O + Energy
Energy from respiration is stored and released
to cells using
adenosine triphosphate
and
diphosphate
adenosine-P-P-P + H2O = adenosine-P-P + P + energy
anaerobic
respiration
(no oxygen)
Muscle cells: glucose ->
lactate
+ energy
oxygen debt
is oxygen
needed to oxidise the lactate
Yeast: glucose -> ethanol + carbon dioxide + energy
Animal cells store as glycogen
Plant cells store as starch, sucrose
Movement of Materials In/Out
Diffusion
Movement to a lower
concentration gradient
affected by...
Concentration gradient
Surface area to volume ratio
Distance
Temperature
Osmosis
Water moving to areas of lower water concentration
(or to areas with higher dissolved substances)
Active Transport
Using energy to move against a concentration gradient
Fungi cells
Yeast: Cell Wall of chitin
NO photosynthesis
Mushroom
Network of
hyphae
=
mycelium
Feed by absorbing nutrients from dead material
Many nuclei in hypha cells
sapotrophic
nutrition = secretes digestive enzyme
breaks down into soluble substances then absorbed
zygote = single
fertilised egg cell
divides by mitosis
ALL chromosomes copied
nucleus splits in 2
cytoplasm divides
differentiation
controlled by genes
specialised to role
except stem cell
embryonic
specialised adult
eg. blood cells
Viruses
parasites
need living cell as host
DNA/RNA
of a few genes
surrounded by protein coat
sometimes steal an 'envelope' membrane
DOMAINS
Archaea
Bacteria
(
prokaryotes
)
single celled
unicellular
spheres, rods, spirals
looped chromosome free-floating in cell
flagella
help it swim
plasmid
rings also contain DNA
decomposers
and can be
pathogens
Eukaryotes
(cells with nuclei)
Plants
Animals
vertebrates
invertebrates
Humans
Fungi
Yeasts (unicellular)
Mushrooms/toadstools
Moulds
Protoctists
Mostly single celled
Features of animal and/or plant
ameoba
- like animals (
protozoa
)
algae
- like plants (with chloroplasts)
some pathogens (plasmodium=malaria)
MICROORGANISMS