Biomolecules
What molecules keep us alive, and how do they do
so?
Open to the next available page in
your journal and construct this chart
Title: Biomolecules
Biomolecule Monomer Function Examples Made up
of:
Carbohydrate
Lipid
Proteins
Nucleic Acids
Biomolecules
• All living organisms require several compounds to
continue to live.
• We call these compounds biomolecules. All of
these biomolecules are organic, which means that
they contain carbon.
• Carbon has four valence electrons, which means this
element forms strong covalent bonds with many other
elements.
Let’s get started!!
Amoeba sisters and Biomolecules
Biomolecules
• All of our biomolecules are classified into four
groups:
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
• Each of these classes have different structures and
functions.
Biomolecules
• Biomolecules are formed by joining many small
units together to form a long chain.
• This process is called synthesis. Often, a water
molecule is removed in the process.
• When this happens, we call it
dehydration synthesis.
Building up polymers
Dehydration Synthesis
• Creates a polymer from a biomolecules
monomers.
• In this process, an OH and H are removed (water)
during synthesis of a new molecule.
8
Breaking down polymers
• Hydrolysis breaks a covalent bond by adding OH
and H from a water molecule.
Biological molecules 10
Dehydration vs. Hydrolysis
Biomolecules
• The smallest functioning unit of a biomolecule is a
monomer.
• “Mono-” means ONE.
• Put two monomers together, and you get a dimer.
• Di-” means TWO.
• Once several monomers are put together, we get a
polymer.
• “Poly-” means MANY.
Carbohydrates
• Carbohydrates are
biomolecules used for
energy and structural
support.
• Breaking
carbohydrates down
provides an organism
with energy.
Carbohydrates
• Carbohydrates are made up • Monomer:
of carbon, hydrogen and Monosaccharide
oxygen. • Dimer: Disaccharide
• The ratio of these • Polymer:
elements is roughly Polysaccharide
1 carbon: 2 hydrogen :1
oxygen.
C6H12O6
Carbohydrates
• Carbohydrates are
primarily used to
provide us with energy.
• All monosaccharides
and disaccharides
end in “-ose”.
• Glucose is used as a
common energy source
for most organisms.
Carbohydrates
• There are many other
types of carbs in nature:
• Fructose (fruit sugar)
• Lactose (milk sugar)
• Sucrose (table sugar)
• Ribose/Deoxyribose
(important for DNA
and RNA)
Carbohydrates
• Carbohydrates can be bonded
to each other through
dehydration synthesis.
• Remember, that’s when
water is lost as two smaller
molecules bond to form a
larger molecule.
Carbohydrates
Carbohydrates
• When we have excess
carbs, we store them
as starches, which are
polysaccharides.
• Starches are long
chains of carbs.
• Plants also use
cellulose (another
polysaccharide) for
structural support.
Carbohydrates
• Indicators are
chemicals that detect
the presence of a
certain compound.
• Benedict’s solution
reacts with MOST
mono- and
disaccharides.
• Sucrose is a notable
exception!
Carbohydrates
• If a detectable carbohydrate is present, then the
indicator changes color, based on how many
carbs are present.
• Green → Yellow → Orange → Red
Carbohydrates
• Iodine is used to detect
starch, since it reacts
readily with starch.
• This reaction
produces a purple-
black coloration.
Lipids
• Lipids are used for four crucial
purposes:
• Storing energy
• Waterproof barriers
• Chemical messengers
• Insulation
Lipids
• Lipids are made up of • Most common lipids are
carbon, hydrogen and composed of two
oxygen. different functional
groups:
• The ratio of these
elements is roughly • Glycerol, an alcohol with
1carbon: 2 hydrogen. three oxygen groups.
Oxygen is present only in
• Fatty acids, which are
trace amounts.
long hydrocarbon chains.
Lipids
• ALL lipids repel water,
due to how
hydrophobic they are.
This means that they do
not bond to water
molecules.
Lipids
• Lipids are grouped by the
number of double bonds
found in the hydrocarbon
chain.
• Saturated fats have the
maximum number of
hydrogen atoms possible, and
as such, they have no double
bonds.
• They tend to be solid at
room temperature.
Lipids
• Unsaturated fats have • Monounsaturated fats
double bonds. They have only ONE double
do NOT have the bond.
maximum possible • Polyunsaturated fats
number of hydrogen have MORE THAN
atoms. ONE double bond in
• They tend to be the hydrocarbon chain.
liquid at room
temperature.
Lipids
Monounsaturated Polyunsaturated
Lipids
• It’s important to note
that fats are a specific
type of lipid.
• Chemically, all fats are
triglycerides – they
have three fatty acids
bonded to one glycerol
molecule.
Lipids
• Steroids are lipids with
four rings bonded
together.
• Steroids are vital as
hormones, which are
chemical signals used in
the body.
Lipids
• Oily and fatty foods tend to • We can also use ethanol,
leave stains upon contact. which dissolves lipids.
• This is why we can • The dissolved fats are
use brown paper to then diluted with water.
detect fats. Since water and lipids
don’t mix, the lipids come
out of solution.
• This creates an emulsion
– a milky, cloudy liquid.
Protein
• Proteins serve many vital
functions in the body:
• Structural support
• Enzymes (Speeding up
chemical reactions)
• Transport of molecules
• Fighting infection
• …and many more!
Protein
• All proteins contain • Monomer: Amino acid
carbon, hydrogen, • Polymer: Protein or
oxygen and nitrogen. polypeptide
• In addition, sulfur may • A peptide is a chain
be present as well. of amino acids, so a
polypeptide is several
chains put together.
Protein
• ALL amino acids
contain an amino or
N-group. It contains
nitrogen (N).
• ALL amino acids also
contain a carboxyl or
C-group. It contains
carbon (C).
Protein
• However, amino acids
also have a variable
group or R-group.
This differs from one
amino acid to the next.
• There are 20 standard
amino acids, and thus
20 possible R-groups.
Protein
• Amino acids are bound
together through
dehydration synthesis.
• The C-group of one
amino acid binds to the
N-group of another.
• We call these bonds
peptide bonds.
Protein
• Proteins can also
function as hormones.
• However, protein
hormones tend to have
difficulty passing the
cell membrane.
• As such, many protein
hormones have to fit a
cellular receptor
before they can affect
the cell.
Protein Production
• Proteins have four phases of production:
• Primary: Amino acids are bound together.
• Secondary: Individual amino acids are bent and
molded as needed.
• Tertiary: The entire chain of amino acids is bent and
molded as needed, forming a sub-unit.
• Quaternary: Multiple completed sub-units are fitted
together to make a complete protein.
Protein Test
Indicator
• The Biuret test is used
to detect protein.
• The test relies on a
color change to confirm
the presence of
proteins. If proteins
are found, the sample
will turn violet.
Hydrolysis
• Hydrolysis is the reverse process of dehydration
synthesis.
• In dehydration synthesis, water is lost to create a
bigger molecule.
• In hydrolysis, water is ADDED, and a bigger
molecule is broken down into smaller pieces.
• Hydrolysis = hydro and lysis. Hydro means water, and lysis
means to break down.
Nucleic Acids
• Nucleic acids are
biomolecules that
contain the blueprints for
making proteins. Nucleic
acids also transmit
genetic info to the next
generation.
• Includes:
• DNA
• RNA
Nucleic Acids
• Nucleic acids • Monomer:
contain carbon, Nucleotides
hydrogen, oxygen, • Polymer: Nucleic
nitrogen, and Acid
phosphorus.
• Examples: DNA,
• Remember the RNA
acronym: CHONP!
Nucleic Acids
Monomer- Nucleotide
• A nucleotide is
made up of three
parts:
• 5-carbon sugar
• Phosphate group
• Nitrogenous
base
Nucleic Acids
• The 5-carbon sugar is
deoxyribose, in the case of
DNA.
• However, it is ribose in the
case of RNA.
• This is how those molecules
got their name!
Nucleic Acids
• As stated earlier, nucleic acids are the blueprints for
proteins. Proteins are made from these templates.
• Also, DNA can be passed on from parent to child.
This allows SOME characteristics to be passed down
to offspring. These traits are considered hereditary.
• RNA can NOT be passed down to offspring,
however!
