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iGCSE Animal Digestive & Gas Exchange Systems - Coggle Diagram
iGCSE Animal
Digestive & Gas Exchange Systems
DIGESTIVE
SYSTEM
FOOD
supply fuel for energy
provide materials for growth & tissue repair
fight disease & keep body healthy
balanced diet
carbohydrates
1% of body
glucose
= C6H12O6
C=carbo H12O6=hydro
Main fuel for cell energy
sugars
fructose, lactose, sucrose
monosaccharide (single)
test for glucose =
Copper Sulphate
disaccharide - two sugars joined together
eg. sucrose = glucose + fructose
eg. lactose = glucose + galactose
polymers = polysaccharides
eg.
starch
,
glycogen
,
cellulose
digesting
starch
-> sugars
test for starch =
iodine
which goes dark blue
lipids
10% of body
also C and H and (much less) O
animal lipids = solid at room T
plant lipids = liquid at room T
fat = energy store
fat = insulation
lipids ->
1xglycerol
+ 3x
fatty acids
(triglycerides)
many different fatty acids
fatty acids with no double bonds
= 'saturated'
cholesterol
= linked to heart disease
proteins
18% of body
in all cells
needed for growth & repair
made of
amino acids
ALL: C, H, O,
N
2 also: Sulphur
formed in a chain of amino acids
in order & folded into a specific shape
order of amino acids
-> decides shape
20x amino acids
so thousands of proteins
eg. collagen, keratin, enzymes,
haemoglobin
humans can make 10 AAs - the others
'essentials' need to be eaten
test = 'biuret' Potassium Hydroxide
then Copper Sulfate
deficiency ->
kwashiorkor
minerals
elements other than
C H O N S
iron, calcium, phosphorus
chlorine, magnesium
vitamins
= chemicals we
need in our bodies
Vitamin A -> makes a light-sensitive
chemical in the retina
from: fish liver oils, liver,
butter, marg, carrots
deficiency ->
night blindness
damaged cornea
Vitamin B Group ->helps with
cell respiration
deficiency ->
beri-beri
Vitamin C -> sticks together
cell lining surfaces
from: fresh fruit & veg
deficiency ->
scurvy
Vitamin D -> helps bones absorb
calcium & phosphate
from: fish liver oils; also made in
skin in sunlight
deficiency ->
rickets, poor teeth
dietary fibre
water
energy content = kilojoules
test = burning in air ->
heat released
Human
Mouth = mechanical digestion
And chemical Carbohydrase
amylase
->
Starch to maltose
from
saliva
Oesophagus
Stomach
Protease
Pepsin
->
Proteins to peptides
Hydrochloric acid to kill bacteria
outlet
sphincter muscle
Small intestine
Duodenum
Carbohydrases
:
Amylase
starch to maltose
Maltase
maltose to glucose
Proteases
:
Trypsin
proteins to peptides
Peptidase
peptides to amino acids
Lipase
:
Lipase
lipids to glycerol & fatty acids
Small intestine
Ileum
Adapted to absorb
Large surface area from
length,
villi
and
microvilli
Large intestine
Colon
Absorbing water
Cellulose, indigestible bits
Water, dead & living bacteria
Cells
1 more item...
Appendix
Each villus had capillaries
Central tube
lacteal
Takes products of fat digestion
And fat droplets
2 more items...
Blood vessels join
Hepatic portal vein
peristalsis
waves
of muscle contraction
move food along
2 more items...
Pancreas
Makes
digestive enzymes
Is alkaline
Liver
makes
bile
Turns lipids into emulsion
Is alkaline
stored in
gall bladder
passes down
bile duct
digestion
speeded
up by
enzymes
GAS EXCHANGE
SYSTEM
air
trachea
LUNGS
bronchi
bronchioles
alveoli
capillary wall (blood)
leakiness
& BP
1 more item...
alveolus
smoking fuses
alveolii
1 more item...
walls contain rings of
cartilage
keeping airways open
C-shaped to allow
food to pass
secrete
mucus
cells with
cilia
to sweep
mucus and dirt away
destroyed by smoking
bronchitis
thorax
(chest)
encloses lungs
2 x
pleural membranes
continuous airtight envelope
pleural cavity
between
membranes
pleural fluid
as lubrication to stop
lungs sticking
ventilation
= moving air
in and out
depends on airtightness
volume change=>
pressure change
= air in or out
(1)
RIBS
intercostal
muscles
internal
contract -> downwards
OUT
but only for deep breathing out
external
contract -> upwards
IN
(2)
DIAPHRAGM
muscles contract
pulls down, flattens
IN
muscles relax
back to dome shape
OUT
separate lungs from abdomen
exhaled air
warmer
saturate H2O vapour
5% less oxygen
4% more CO2
Smoking = Bad
kills cilia
damages alveoli
carbon monoxide
binds with
haeomoglobin
more easily than air
forms
carboxyhaemoglobin
less oxygen in blood
contains
nicotine
contains
carcinogens
can lead to a
tumour