Before we begin… lets take a moment and
remember what a chemical reaction is.
What is in the food you eat?
Our food is made up of organic
macromolecules.
______ ______________
Organic means that they
contain carbon atoms.
Remember: Carbon is one of
the building blocks of life.
That means that everything
alive contains carbon!!!
Macromolecules means that
they are large molecules
made up of smaller
molecules.
There are 4 major organic macromolecules:
1. Carbohydrates
3. Proteins
2. Lipids
4. Nucleic Acids
ALL living things are made up of the 4 main organic
molecules!
How do we get these macromolecules in our
bodies?
Do our bodies just produce all of the
macromolecules we need????
We get the macromolecules that we
need through the food we eat!
What’s in a cheeseburger?
Nutrition Facts (Big ‘N Tasty at
McDonalds):
Calories: 520
Total Fat: 29 grams
Saturated Fat: 9 grams
Carbohydrates: 41 grams
Protein: 24 grams
Carbohydrates
Which part of the
cheeseburger do
you think contains
the most
carbohydrates?
What exactly are carbohydrates?
Carbohydrates are compounds made of C (carbon),
H (hydrogen), and O (oxygen) atoms.
In our bodies, carbohydrates are used
primarily to store and release energy for a
short amount of time!!
How do 3 atoms turn into a bowl of noodles?
Atoms come together to make molecules and
then the molecules join together to make even
larger molecules.
Atoms
molecule
2 molecules
3 molecules
One molecule of carbohydrate is called a
monosaccharide.
The root word of
monosaccharide is
“sacchar” which
means sugar.
Therefore a monosaccharide is a simple sugar.
The most common monosaccharide has
become famous in our class…
GLUCOSE
Glucose is a 6 C
sugar that is
shaped like a
hexagon.
Glucose is not the only example of a
monosaccharide...
Another example is fructose.
Fructose is a 6 C
sugar that is
shaped like a
pentagon.
Two sugar carbohydrates put together is called
a disaccharide.
An example of a disaccharide is lactose.
Lactose is the sugar found in milk!
What does it mean to be lactose intolerant?
What type of sugar do our bodies use for energy?
To get glucose out of food,
our bodies have to break
down multi-sugar
carbohydrates.
If you are lactose intolerant,
it means that your body
lacks the ability to break
lactose down and therefore
are unable to digest it.
Another example of a disaccharide is sucrose.
Sucrose is what we use as table sugar.
Sucrose is made up of one molecule of glucose
bonded to one molecule of fructose
When there is more than 2 monosaccharides
bonded together we call it a polysaccharide.
One example of a polysaccharide is starch.
Starch is a branched chain of glucose.
Plants make starch to be a food storage molecule.
Have you ever heard someone refer to a food as “starchy”?
What does that mean?
It means that the
food contains a
lot of starches.
Usually this food
will be a
vegetable.
Why?
Another example of a polysaccharide is glycogen.
Glycogen is a highly branched chain of glucose.
Animals make glycogen to store excess glucose that
is broken down during a meal.
Why is glycogen so important?
GLYCOGEN
If we didn’t have glycogen we
would have no way to store our
extra glucose from our food and
we would have to eat a lot more
often!
extra glucose
Another example of a polysaccharide is cellulose.
Cellulose is a chain of glucose hooked together like a chain
link fence.
Made by plants for structural support.
Why do plants need cellulose?
Plants don’t have bones like we do, so they have to
have something that supports them and helps them
stay upright.
Their cells are
lined with
cellulose to help
them stay rigid.
Since cellulose is so rigid humans cannot digest it.
Humans cannot break apart cellulose into glucose!!
Celery is pure cellulose, so
we don’t get any energy
out of it!
Let’s recap!
C, H, and O atoms
Monosaccharides
Disaccharides
Polysaccharides
Branched chain of
glucose
Chain of glucose
hooked together like
a chain link fense
Highly branched chain
of glucose
Is bread the only thing we eat that has
carbohydrates in it?
NO!
Fruits and
vegetables also
have
carbohydrates
in them!
Back to our cheeseburger…
Why wouldn’t the lettuce on our cheeseburger
be a good source of energy?
Hint: think about the types of polysaccharides and
what type a leaf might have…
Lettuce is full of
cellulose!!!!!!!!
Let’s say that you were going to run a marathon
tomorrow, would you want to eat lots of pasta and
other carbohydrate-rich foods tonight??? YES!!
Marathon runners “carb load”
before a race because
carbohydrates help give them
the short-term energy they
need to finish the race!