Macromolecules
Unit 5
Macromolecules

Living tissue is composed of a diverse array
of carbon-based molecules called
macromolecules.
Macromolecules

The big picture:
Macromolecules provide
for specific biological activity
Provide energy storage
 Information storage
 Structural components
 Catalytic activity

Macromolecules

There is a biological unity among all
organisms due to the fact that they are
composed of four major biological
macromolecules
Macromolecules

The four classes of macromolecules:
–
Carbohydrates – primary energy source
–
Lipids-energy storage
–
Proteins – structural support, protection, movement
–
Nucleic Acids – store, transmit, and use genetic info
Macromolecules
 Vocabulary
Macromolecules
- Monomomers -tiny molecules strung in long
repeating chains called polymers.
Macromolecules

Polymer – are the backbone of the
molecule
Macromolecules
Hydrolysis of macromolecules
Polymers are disassembled or broken down by
the process of hydrolysis, as bonds between
monomers are broken by the addition of
water
Macromolecules

Example:
Hydrolysis of starch
1. Start with Starch
2. Introduce the enzyme, amylase, which can
break down starch to maltose
3.The enzyme maltase can break down
maltose to glucose
–
4. Glucose
ENERGRY
Macromolecules

Example- digestion

Most of the food we consume is too large to
enter our cells.
Enzymes within the digestive tract hydrolyze
the food into monomers that are absorbed
into our blood stream for distribution to all
body cells.

Macromolecules
Reagent is more specifically a test
substance that is added in order to
bring about a reaction or to see
whether a reaction occurs
Macromolecules

Today we will run four tests to find different
macromolecules.
Macromolecules

1. Carbohydrates – Most foods contain
carbohydrates, which the body breaks down
into simple sugars — the major source of
energy for the body.
–
composed of monomers called monosaccharide ( simple sugars)
–
They can be linked to form disaccharides ( sucrose)
Contain a double-bonded oxygen atom ( carbonyl group)
–
Macromolecules
Benedict’s test for reducing sugars
Carbohydrates will react with Benedict’s reagent
to form a precipitate that varies in color
depending on the sugar concentration.
Macromolecules

A color change to
yellow, orange or red
indicates a positive
test for reducing
sugars.

If test tube color
remains blue (the color
of Benedict’s reagent) it
is a negative result.
Macromolecules
Iodine test for starch
In the presence of iodine a solution containing
starch will turn blue-black in color
Macromolecules


Iodine will be added to each of the test tubes.
A color change to blue-black indicates a
positive test for starch.
If test tube color remains yellow-orange (the
color of iodine) it is a negative result.
Macromolecules
2.Lipids - structurally diverse that are classified
together because they are all insoluble in water
(hydrophobic)
When mixed with water, lipids clump together as a
result of hydrophobic interactions.
Lipids include fats, oils, steroids, and waxes.
Macromolecules
Sudan IV test for lipids
When testing for the presence of lipids in a solution you will use a Sudan IV
Test.
In this test dark red Sudan IV is added to a solution along with ethanol to
dissolve any possible lipids.
If lipids are present the Sudan IV will stain them reddish-orange, giving a
positive test.
Macromolecules
3. Proteins - Proteins are the most complex
and functionally diverse molecules of living
organisms.
–
Proteins compose enzymes, blood cells and
muscle tissue just to name a few and are
therefore associated with meat products.
Macromolecules

We will test for the presence of protein using
the Biuret Test.

Like the Benedict’s Reagent, Biuret Reagent
contains copper ions…………….
Macromolecules

These copper ions cast
a violet color to a
solution with proteins

This violet color is a
positive reaction in a
Biuret Test