Transcript What do we digest? What is food made up of?

What do we digest?
What is food made up
of?
Carbohydrates
Proteins
Fats
Water
These are called MACRONUTRIENTS
(Because they are big!)
Vitamins and Minerals are called
MICRONUTRIENTS
Is the body breaking down
and digesting food an
example of a chemical
reaction?
Yes?
No?
We make some molecules in our
own body that make these
chemical reactions go faster
Why do you think we do this?
Enzymes
A molecule made out of protein
that makes all chemical
reactions in living organisms
faster
Its like having fuel injection in
your car to make it faster
Except enzymes never run out
They are like rechargeable
batteries
And keep going and going and
going………
Where do we digest
proteins?
a)
b)
c)
d)
In
Rectum and Stomach
Small Intestine and stomach
Stomach and Mouth
Liver and kidneys
the stomach and small
intestine
http://kitses.com/animation/swfs/d
igestion.swf
So what helps us digest
proteins?
Hydrochloric acid in the stomach
Enzymes?
Pepsin in the stomach
Proteases in the small intestine
What is the pH of the
stomach?
• 1 – 3 in a normal human
Why does pepsin work well in the
stomach?
• Because it is fully active in an
acidic solution
Carbohydrates
Where do we digest these?
a) Mouth and Liver
b) Large Intestine and small
intestine
c) Stomach
d) Mouth and small intestine
Answer = d
What helps us digest
carbohydrates?
An enzyme called?
Amylase : In the mouth
Amylase : From the pancreas
What helps us to digest fats?
Where are they digested?
Digested in the small intestine
Bile is produced from the?
Liver and stored in the ?
Gall bladder
And this drains into the?
Small intestine
Bile breaks up the fat so it is
easier for the enzymes to digest
Its like a natural dishwashing
detergent
The small intestine
What is the pH of the
small intestine?
Generally it is around neutral,
although the first section will be
slightly acidic (6 – 6.5) and the
second two sections will be
slightly basic or neutral (7 – 8)
Inside the small
intestine
The Villi
What it looks like with
Crohns disease
The large intestine
Inside the large
intestine
What happens in the
large intestine?
Absorbs water from the waste
Absorbs any minerals that are left
and some vitamins.
Bacteria in the faeces will make
some vitamins, like B12
Diseases of the Large
Intestine
• These include Diverticulitis –
pouches and pockets form in the
walls of the large intestine and some
of these get faeces trapped in them,
get inflamed and infected.
• Polyps: bulb like growths on the
lining
• Ulcerative colitis – chronic
inflammation, bleeding and scaring
of the mucus lining of the large
intestine.
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