Download Nutrition in animals

• Describe the functions of main regions of the alimentary
canal and the associated organs: mouth, salivary glands,
oesophagus, stomach, duodenum, pancreas, gall
bladder, liver, ileum, colon, rectum, anus, in relation to
ingestion, digestion, absorption, assimilation and
egestion of food, as appropriate.
• Functions of a typical amylase, protease and lipase
(listing the substrate and end-products)

Holozoic nutrition: feeding on readymade complex organic matter.

The taking in of food (chemical
energy) by the body &
converting it into living matter
5 processes in digestion
INGESTION
Taking in food
DIGESTION
Breakdown of complex
food substances into smaller
soluble food substances
ABSORPTION
Digested food is absorbed
Into body cells
ASSIMILATION
Absorbed food is use to
provide energy or form
new protoplasm
EGESTION
Removal of undigested food
 Feeding/
Ingestion – intake
of food into the mouth.


Digestion – large food molecules are
broken down into small, soluble and
diffusible molecules.
2 types: Physical and chemical
digestions
1.
Physical digestion refers to the
mechanical break up of food into
small particles which increases
its surface area for chemical
digestion. (E.g. Chewing,
stomach churning). It also mix
the digestive enzymes with the
food particles
1.
Chemical digestions – breaking
of biomolecules like proteins,
starch and fats into small soluble
molecules which can be absorbed
by the cells. It involves digestive
enzymes and chemical reactions
like hyrolysis.
Why must food
Cell
membranes
are
molecules
be broken
partially
permeable
down into
smaller,
simpler
before it
and forms
only allow
can bemolecules
absorbed by
small
to
the
cells
for other
pass
through.
uses?
 Absorption
– digested
food materials are taken
into the body cells.
 Assimilation
– absorbed
food materials are converted
into new protoplasm or
used to provide energy.
 Egestion
Do not
confuse
Ingestion
with
Egestion!!!
– elimination of
undigested food materials
(faeces)
Starch
AMYLASE
Proteins
PROTEASE
Lipids/ Fats
LIPASE
maltose
amino acids
fatty acids &
glycerol
The Digestive
System
Consists of:
1) The gut or alimentary
canal (9 m) from mouth
to anus.
2) Glands (A cell, tissue,
or organ that secretes a
chemical substance).
3) Associated organs.
Mouth & Buccal
Cavity
Buccal Cavity
1.
Food enters through the mouth. This
process is called ingestion.
2.
Teeth cuts food into small pieces. This
increases surface area to volume ratio
for enzyme to act more efficiently.
1.
Salivary glands produce saliva to
moisten food.
2.
Saliva also contains salivary amylase to
break down starch to maltose.
3.
pH of saliva is neutral (around pH 7).
Salivary Glands
Salivary Amylase
Starch
Maltose
Salivary amylase is active at pH 7.
1.
Tongue rolls food into boli.
2.
Food is swallowed and enters
the pharynx.
• Made up of a tubular
gut called the
alimentary canal.
• Food travels through
our body along the
alimentary canal
which is a continuous
tube beginning at the
mouth and ending at
the anus.
• The parts of the gut
includes: mouth,
pharynx, oesophagus,
stomach, small
intestine, large
intestine and anus.
mouth
pharynx
oesophagus
stomach
small intestine
large intestine
Rectum
anus
Mouth & salivary glands
 Pharynx, Oesophagus
 Stomach
 Small intestine- duodenum &
ileum
 Associated organs-liver, gall
bladder, pancreas
 Large intestine- colon, rectum
 Anus

mouth
pharynx
salivary gland
oesophagus
liver
stomach
gall bladder
duodenum
pancreas
jejunum
colon/ large intestine
ileum
rectum
anus
What we learn today.
• Nutrition (Definition)
• 5 Processes of Nutrition
• Digestive Enzymes
• Alimentary Canal
• Alimentary Canal & Accessory Organs
duodenum
pharynx
gall bladder
jejunum
liver
salivary gland
ileum
oesophagus
anus
stomach
colon/ large intestine
rectum
mouth
pancreas