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MACROMOLECULES
(CARBOHYDRATES AND LIPIDS)
IB Bio I
Van Roekel
9/30/15
1
BILL - MACROMOLECULES
Why is carbon one of the most essential elements
to living organisms?
Carbon atoms can form up to four covalent
bonds with various elements. This allows for a
diversity of stable elements to be formed and
makes carbon the base of all organic molecules
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CARBON (C)
•Carbon has 4 electrons in outer shell.
•Carbon can form up to 4 covalent bonds
with 4 other atoms (elements).
•Usually with C, H, O or N.
•Allows it to be the base for a diversity of
stable compounds to form
•Example: CH4(methane), C6H12O6 (Glucose)
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ORGANIC COMPOUNDS
Organic Compounds – Compounds that
contain carbon and are found in living
organisms
Life is based on Macromolecules, or large
organic molecules.
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MACROMOLECULES
•Each Macromolecule (polymer) is composed of smaller
subunits, or building blocks (monomers), that can be
viewed individually
•Carbohydrates (polysaccharides)  monosaccharides
•Proteins  Amino Acids
•Lipids  Fatty Acids & Glycerol
•Nucleic Acids  Nucleotides
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WHAT DO ORGANISMS DO WITH THESE
MACROMOLECULES?
oUse the energy stored in macromolecules
to carry out various chemical reactions in
the body, or for their metabolism
oMetabolism – All of an organism’s/cell’s
chemical reactions
o Various metabolic pathways are used to
breakdown/form molecules in the body
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TWO TYPES OF METABOLISM
Catabolism
Anabolism
Reactions that RELEASE
ENERGY by breaking down
complex molecules to
simpler compound
Reactions that CONSUME
ENERGY to build
complicated molecules from
simpler ones
Occurs by hydrolysis
reactions - Separates
polymers into monomers
by “adding water”
Occurs by condensation
reactions - Forms
polymers by combining
monomers by “removing
water”.
Water used as a reactant
Water is a product
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QUESTION:
HOW ARE
MACROMOLECULES
FORMED?
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ANSWER: CONDENSATION REACTIONS
Also called “dehydration synthesis”
Forms polymers by combining monomers by
“removing water”.
HO
H
HO
H
H2O
HO
H
9
QUESTION:
HOW ARE
MACROMOLECULES
SEPARATED OR DIGESTED?
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ANSWER: HYDROLYSIS
Separates polymers into monomers by
“adding water”
HO
H
H2O
HO
H
HO
H
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BILL
What is metabolism? Describe the two types of
metabolism.
Metabolism is the totality of an organism’s, or a cell’s,
chemical reactions. There are two types of metabolic
reactions.
The first is catabolism, in which molecules are broken
down from complex versions to simpler ones and release
energy in the process.
The second is anabolism, in which complex molecules are
built from simpler ones and energy is consumed.
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MACROMOLECULES
•Each Macromolecule (polymer) is composed of smaller
subunits, or building blocks (monomers), that can be
viewed individually
•Carbohydrates (polysaccharides)  monosaccharides
•Proteins  Amino Acids
•Lipids  Fatty Acids & Glycerol
•Nucleic Acids  Nucleotides
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Glucose
This is the basic mono-saccharide (single sugar molecule) that is
used in respiration. It stores chemical energy.
General formula: C6H12O6
We count the carbons in
clockwise direction, starting
with the first carbon after the
oxygen atom in the ring.
Ribose
This is the basic mono-saccharide (single sugar
molecule). It is found in RNA and a similar version in
DNA.
General formula: C5H10O5
We count the carbons in
clockwise direction, starting
with the first carbon after the
oxygen atom in the ring.
A generalized amino acid
All amino acids consist of an amino group, a carboxyl group, a carbon and hydrogen
molecule, and a unique R-group. Some are polar, others non-polar and their different
properties determine their interactions and the shape of the final protein.
Double Bond
Hydroxyl Group
Amino Group (-NH2)
The amino group is one of the
reasons why nitrogen is an
important element in living
things.
Carboxylic Acid Group (-COOH)
The carboxylic acid group contains
an oxygen double-bonded to the
carbon and a hydroxyl group (-OH)
that can be lost to form new bonds.
Methionine: an amino acid
There are 22 different protein-making amino acids,
though only 20 are coded for in genetic code.
Methionine is an important amino acid as it is coded
by the START codon in mRNA (AUG). This means that
is is the first amino acid in all polypeptide chains as it
is the first produced in transcription in the ribosomes.
Sulphur
forms strong
bonds
(disulphide
bridges) with
other Scontaining
amino acids.
Although methionine (Met) has quite a large Rgroup, we can still identify the amino group and
carboxylic acid group on the amino acid.
The simplest amino acid is
glycine, with H in the Rgroup position.
http://en.wikipedia.org/wiki/Methionine
Lipids (Fatty Acids & Glycerol)
Fatty acid chains can be of many lengths, extended by adding CH2 units. They are an
efficient storage of energy and bond with glycerol (a simple sugar alcohol) to make
triglycerides – lipids.
A generalized Nucleotide
Individual nucleotides consist of three major parts: one phosphate group, one 5carbon monosaccharide, and a single nitrogenous base.
Four possible nitrogenous bases in DNA (Adenine, Guanine, Thymine, and Cytosine)
Four possible nitrogenous bases in RNA (Adenine, Guanine, Uracil, and Cytosine)
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Which molecule represents ribose?
D
What molecule does letter C represent?
Glycerol
What is molecule B?
Amino Acid
CARBOHYDRATES
CARBOHYDRATES
Class of molecules ranging from small sugar
molecules (monosaccharides) to large sugar
molecules (polysaccharides).
Examples:
A. monosaccharide (monomer)
B. disaccharide
C. polysaccharide
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CHARACTERISTICS OF CARBOHYDRATES
Consist of carbon, hydrogen, & oxygen in a ring
formation
Monosaccharides combine through condensation
reactions to form disaccharides and polysaccharides
Functions:
Energy containing molecules
Some provide structure
CARBOHYDRATES
Monosaccharide: monomers of carbohydrates are
composed of a single sugar molecule
General structure of monosaccarhides: (CH2O)n
n usually equals 3 (trioses), 5 (pentoses) or 6 (hexoses)
Examples:
*glucose (C6H12O6)
*Fructose
Galactose
Deoxyribose
*Ribose
*State one function of carbohydrate
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FUNCTIONS OF MONOSACCHARIDES
•Glucose: main fuel
(source of energy) for
cellular respiration
(process of extracting
energy from molecules)
•Fructose : Found in plant
cells, makes them sweet,
provides energy.
•Ribose: Structural
component of RNA
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TWO MINUTE CONVO
Why is it beneficial for fruits to produce fructose,
which is a sweet tasting monosaccharide?
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BILL - Identify these organic molecules.
fatty acid
ribose
glucose
amino acid
Different Forms of Glucose
CARBOHYDRATES
Disaccharide: two sugar unit
Examples:
*Sucrose (glucose+fructose)
*Lactose (glucose+galactose)
*Maltose (glucose+glucose)
glucose
glucose
* State one function of Carbohydrate
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FUNCTIONS OF DISACCHARIDES
•Sucrose: Main
carbohydrate in plant sap,
nourishes all the parts of
the plant
•Lactose: Sugar molecules
found in milk, provides
nutrients to offspring
•Maltose: Important
intermediate in the
digestions of starch and
energy storage
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CARBOHYDRATES
Polysaccharide: polymers of carbohydrates
composed of many sugar units
Examples:
*starch (bread, potatoes)
*glycogen (beef muscle)
*cellulose (lettuce, corn)
glucose
glucose
glucose
glucose
cellulose
glucose
glucose
glucose
*State one Function of Carbohydrate
glucose
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FUNCTIONS OF POLYSACCHARIDES
•Starch: storage of glucose in the roots and other
tissues of plants. Consists entirely of glucose.
•Cellulose: Forms cable-like fibers in walls that
enclose plant cells, known as cell wall. Composed
of glucose, but monomers are linked in different
orientation
•Glycogen: storage of glucose in liver and muscle
cells. Consists entirely of glucose, more branched
than starch
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BILL - CARBOHYDRATES
Discuss the properties (structure and function) of
monosaccharides, disaccharides, and
polysaccharide. And Give an example of each
one.
Monosaccharides – single sugar units, the monomers of carbohydrates.
Primary source of energy for cells, some can be structural. Glucose is
the main source of energy for cells
Disaccharides – two sugar units. Nutritional molecules for plants and in
milk for offspring. Sucrose is the main source of nutrients for all parts
of a plant
Polysaccharides – Multiple sugar units. Storage of glucose in plants
and animals, also structural component of cell wall. Glycogen stores
glucose in the muscle and liver cells of animals
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CONDENSATION REACTIONS IN
CARBOHYDRATES
•Condensation molecules will remove water to
allow two monosaccharides to bond together.
•One monomer gives up a hydroxyl group (-OH), the
other gives up a hydrogen molecule from a hydroxyl
group (-H)
•Leaves an oxygen molecule to bind two
monosaccharides, forming what is called a glycosidic
bond
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Link
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HYDROLYSIS OF CARBOHYDRATES
•The majority of carbohydrates in food are too large to
enter our cells, so they must be broken down
•Hydrolysis breaks poly-/disaccharides down using water
as a reactant
•Hydrolase – enzyme that catalyzes/causes the
hydrolysis of glycosidic bonds between carbohydrates
•Exposes a negatively charged oxygen on one monomer,
and a positively charged carbon on the other monomer.
•One hydrogen (-H) attaches to the negative oxygen on
one monomer and a hydroxyl (-OH) attaches to the
positive carbon on the other
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Hydrolysis of a Disaccharide
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ANNOTATE A CONDENSATION REACTION
OF THE TWO MONOMERS BELOW
Oxygen is used to combine
the negative and positive
carbons in a glycosidic bond
-
-H is attracted to negative -OH and
breaks away, leaving its electrons
behind, making carbon negative.
-OH molecule breaks away from
carbon and takes electrons, becoming
negatively charged, while carbon
becomes positive
+
H2O
-H and –OH combing to form
water
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ANNOTATE A HYDROLYSIS REACTION OF
THE MALTOSE MOLECULE BELOW
-
Hydrolase breaks the
glycosidic bond between
oxygen and carbon.
The oxygen takes the
shared electrons, making
oxygen negative and the
carbon positive
+
H OH
A hydrogen molecule from
water joins the negative
oxygen. The hydroxyl
molecule from the water
joins the positive carbon
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LIPIDS
LIPIDS
General term for compounds which are not soluble in
water.
Remember: “Lipids store the most energy”
Examples:
1. Fats
2. Phospholipids
3. Oils
4. Waxes
5. Steroid hormones
6. Triglycerides
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Characteristics of Lipids
• Composed of Carbon, Hydrogen, and Oxygen
• Greater than 2:1 ratio of H:O
• Building blocks are fatty acids and glycerol.
– 3 types of fatty acids (saturated, unsaturated, and
polyunsaturated)
• Not considered a polymer, because fatty acids and
glycerol molecules are not repeating
• Functions
– Energy storage molecules
– Insulators
– Phospholipids part of cell membrane
Glycerol
Fatty Acid Structure
•Carboxyl group (COOH) forms the acid.
•“R” group is a hydrocarbon chain (ranges from 11-23 carbons).
•Ends with a methyl group (-CH3)
A Representative Fatty Acid
Carboxyl Group
Hydrocarbon
chain
Methyl Group
FATTY ACIDS
There are two kinds of fatty acids you may see these on food
labels:
Saturated fatty acids: no double bonds (bad)
saturated
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
Unsaturated fatty acids: double bonds (good)
• Monounsaturated (one double bond)
• Polyunsaturated (two or more double bonds)
O
unsaturated C-CH2-CH2-CH2-CH
60
Unsaturated
Fatty Acid
Saturated
Fatty Acid
SATURATED FATTY ACIDS
No double bonds between carbon atoms in hydrocarbon
chain (straight chain)
The structure is saturated with hydrogen ions (carry as
many hydrogen atoms as they can)
Found in animal products (butter, bacon, fat in red meats)
Generally solid at room temperatures
Diet rich in saturated fats is a factor in cardiovascular
disease
saturated
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
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UNSATURATED FATTY ACIDS
Contains double bonds, which results in two empty spaces where hydrogens
should be.
Creates a bend/kink in the hydrocarbon chain
Typically come from plants (olive oil) and are liquids at room temperature
Monounsaturated – has one double bond within the hydrocarbon chain
Polyunsaturated – has two or more double bonds within hydrocarbon chain
monounsaturated
O
C-CH2-CH2-CH2-CH
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BILL
What is the difference between saturated and
unsaturated fatty acids?
•Saturated fatty acids have no double bonds between
carbon molecules in the hydrocarbon chain and are said to
be saturated with hydrogen atoms. Typically solids
•Unsaturated fatty acids have double bonds between
carbon molecules in the hydrocarbon chain. There are two
types, monounsaturated (1 double bond) and
polyunsaturated (2 or more double bonds). Typically
liquids.
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Unsaturated
Fatty Acid
Saturated
Fatty Acid
TRANS VS. CIS UNSATURATED FATTY ACIDS
Cis Unsaturated
Trans Unsaturated
Hydrogen atoms are on
same side of double bond
Hydrogen atoms are on
opposite sides of double
bond
Naturally occurring
Result of hydrogenation of
natural fats (manual
addition of hydrogen
atoms)
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TRANS VS. CIS UNSATURATED FATTY ACIDS
Affects the shape of the fatty acid molecules
Cis Unsaturated
Trans Unsaturated
Double bonds result in a
kink in hydrocarbon chain,
causing the fatty acid to be
curved
No kink in hydrocarbon
chain, causing the fatty
acids to be straight
Typically liquid and more
flexible
Healthier (omega-3)
Typically solid (like
saturated) and less flexible
Less healthy (fast food oils,
margarine)
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TRANS VS. CIS UNSATURATED FATTY ACIDS
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Synthesis of a Triglyceride
Condensation of Fatty Acids and
Glycerol
• 3 fatty acids and 1 glycerol molecule combine
to form a triglyceride (fats/oils)
• 1 Hydrogen (from hydroxyl group) in glycerol
and the hydroxyl group from each fatty acid
leave as water
• Exposed bonds form an ester bond
• This happens for each fatty acid, which results
in the formation of a triglyceride (with 3 ester
bonds) and 3 water molecules
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Link
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TRIGLYCERIDES
glycerol
H
fatty acids
O
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
H-C----O C-CH -CH -CH -CH
2
2
2
H
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2 minute Convo
• Have you heard of Omega-3, and Omega-6 Fatty acids? Do
you think they are saturated or unsaturated? Cis- or TransConservation?
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LIPIDS
Six functions of lipids:
1. Long term energy storage
2. Major component of membranes
(phospholipids)
3. Chemical messengers (hormones/steroids)
4. Protection against heat loss (insulation)
5. Protection against physical shock
6. Protection against water loss (waxy layers of
plants)
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LIPIDS – ENERGY STORAGE
Triglycerides (fats and oils) are energy
storage molecules
Body stores excess food as fat in adipose
tissue
Very efficient energy storage molecule
Stores approximately twice as much energy
as carbohydrate (38 kJ/g compared to 17 kJ/g)
However, they are much harder to
digest/breakdown so it is less efficient at
releasing energy
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Carbohydrates vs Lipids for energy storage
A Phospholipid
Phospholipids
• Composed of 2 fatty acid
tails (hydrophobic), and a
Phosphate group bound
with a glycerol molecule
(hydrophilic)
• Form lipid bilayer of cell
membrane
• Serves as boundary
between cell and external
environment
Phospholipid Bilayer
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Hormones/Steroids
• Steroids & hormones are lipids whose
carbon skeleton is bent to form a ring
structure.
• They vary in function but most act as
chemical messengers that control/affect
various parts of the body
– Regulate metabolism (Thyroid Stimulating
Hormone)
– Immune response (Cortisol)
– Reproduction (Estrogen & Testosterone)
• Example: Cholesterol is a component of
the animal cell membrane and is a
precursor to make other steroids
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Insulation
• Lipids are important for thermal insulation as they have the
ability to retain heat
• Cold–climate animals form layers of blubber to help stay
warm
• Some seals have 30% of body mass from blubber
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What are some uses of lipids in living things?
2 minute convo
• Discuss 3 different types of functions of lipids
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What are some uses of lipids in living things?
Carbohydrates vs Lipids for energy storage