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Biomolecules-Students-Copy

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Biomolecules
What molecules keep us alive, and how do they do
so?
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.
7
Breaking down polymers
• Hydrolysis breaks a covalent bond by adding OH
and H from a water molecule.
Biological molecules
9
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
oxygen.
• The ratio of these
elements is roughly
1 carbon: 2 hydrogen :1
oxygen.
C6H12O6
Monosaccharide
• Dimer: Disaccharide
• Polymer:
Polysaccharide
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 purpleblack coloration.
Concept Check! TRUE OR FALSE
1. Glucose is an example of a complex sugar.
2. Biomolecules are also known as “inorganic compounds”.
3. Monomers combine with other monomers using covalent
bonds to form more complex and larger molecules.
4. Water molecule is remove in the process of bonding two
monomers in a dehydration synthesis.
5. Most biomolecules are made from single subunits, or building
blocks, called polymers.
6. Polymers are broken down into its constituent monomers in a
process known as hydrolysis where a water molecule is lost in
the process.
Concept Check! TRUE OR FALSE
7. Carbohydrates are made up of elements Carbon, Hydrogen and
Oxygen with the ration 2:2:1
8. Starches and glycogen are considered as disaccharides.
9. Animal storage carbohydrate is termed chitin.
10. Combining glucose and fructose yield galactose.
11. Monosaccharide has one single unit of sugar like sucrose.
12. The main function of a carbohydrate is to provide energy.
13. Maltose is a combination of two monosaccharides.
14. Cellulose is a polysaccharide found on the plant cell wall.
15. Lactase is a form of carbohydrate.
Lipids
• Lipids are used for four crucial
purposes:
•
•
•
•
Storing energy
Waterproof barriers
Chemical messengers
Insulation
Lipids
• Lipids are made up of
carbon, hydrogen and
oxygen.
• The ratio of these
elements is roughly
1carbon: 2 hydrogen.
Oxygen is present only in
trace amounts.
• Most common lipids are
composed of two
different functional
groups:
• Glycerol, an alcohol with
three oxygen groups.
• Fatty acids, which are
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
double bonds. They
do NOT have the
maximum possible
number of hydrogen
atoms.
• They tend to be
liquid at room
temperature.
• Monounsaturated fats
have only ONE double
bond.
• Polyunsaturated fats
have MORE THAN
ONE double bond in
the hydrocarbon chain.
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
use brown paper to
detect fats.
• The dissolved fats are
then diluted with water.
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
carbon, hydrogen,
oxygen and nitrogen.
• In addition, sulfur may
be present as well.
• Monomer: Amino acid
• Polymer: Protein or
polypeptide
• A peptide is a chain
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
contain carbon,
hydrogen, oxygen,
nitrogen, and
phosphorus.
• Remember the
acronym: CHONP!
• Monomer:
Nucleotides
• Polymer: Nucleic
Acid
• Examples: DNA,
RNA
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!
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