Transcript macromolecules

Orgainic/inorganic pg. 14 sg
• Some cpds which contain carbon are
inorganic.
Examples include carbon dioxide,
carbonates, and hydrogen carbonates.
All cpds which contain no carbon are
inorganic
Three types of organic cpds are found in
living things, carbohydrates, proteins,
lipids
Structure
• Carbon atoms can share electrons notable being other carbon atoms,
hydrogen atoms and oxygen atoms.
• The simplest organic molecules are
defined as being comprised of only carbon
and hydrogen = hydrocarbons
• Hydrocarbons are non-polar,
hydrophobic compounds. (water hating)
• Compounds that have no charges on them
will not mix with polar water.
• Hydrophilic comes from the Latin roots
"hydro" (water) and "philia" (love).
• Compounds are polar, and so dissolve
easily in the polar solvent water.
• Structural formulas of some simple
hydrocarbons.
• Methane CH4:
Hydrocarbons
• A simple chain of
carbons with its full
complement of
hydrogens is said to
be saturated.
• known as alkanes.
• name ends with 'ane'.
• Hydrocarbons with
double bonds in them
are said to be
unsaturated.
• contain at least one
double bond.
• Alkenes
Branching chains
• Sometimes two
hydrocarbon
molecules can have
the same numbers of
the same atoms but
have different
arrangements of
these atoms. We say
they are isomers.
Role of hydrocarbons in fats
• A fat molecule
consists of a small,
non hydrocarbon
component joined to
three hydrocarbon
tails. The tails can be
broken down to
provide energy.
Mammalian adipose
cells stockpile fat.
Functional Groups Parts of the
molecules of life.
• Part of your homework tonight is to go to
this web site: Building Biomolecules: The
Functional Groups
• Review each of the functional groups and
do the self quiz.
Functional groups
Adenosine triphosphate or ATP
Phosphate groups
• In biology this is an important group found
in ATP.
• Structurally, ATP consists of the adenine
nucleotide (ribose sugar, adenine base,
and phosphate group, PO4-2) plus two
other phosphate groups.
Exergonic / Endergonic Reactions
• Energy releasing processes, ones that
"generate" energy, are termed exergonic
reactions.
• Reactions that require energy to initiate
the reaction are known as endergonic
reactions
ATP = The primary energy
transferring molecule in cells
Macromolecules – page 15sg
• Monomers make polymers. Polymers are
long molecules consisting of many similar
or identical building blocks linked by
covalent bonds.
Condensation Reaction
• Monomers are connected by a reaction in
which two molecules are covalently
bonded to each other through loss of a
water molecule, also known as
condensation reaction (also called
dehydration synthesis .
• Dehydration Synthesis-Hydrolysis
Hydrolysis
• Means - to break with water. Bonds between
monomers are broken by the addition of water
molecules, a hydrogen from the water attaching
to one monomer and a hydroxyl group attaching
to the adjacent monomer. This occurs in the
digestive tract. Dehydration SynthesisHydrolysis
• Biology I Interactive Animations (go to
biochemistry section)
Carbohydrates – fuel and building
molecules pg 15 sg
• Carbohydrates have the general molecular
formula CH2O
• The simplest CHO are monosaccarides.
• Disaccharides are double sugars (formed
by dehydration synthesis)
• Polysaccharides are made of many sugars
Monosaccharides
• Glucose is the most common
monosaccharide and is vital to life
• Three common sugars share the same
molecular formula: C6H12O6. Because of
their six carbon atoms, each is a hexose.
Name 2 monosaccharides p 15 sg
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Glucose
Fructose
Galactose
Ribose
Glucose has the trademarks of a
sugar pg 14 sg
• A hydroxyl group is
attached to each
carbon except one,
here you find a
double bond to
oxygen
• Used as major nrg
source for cells
• (2.2.8)
Glucose comes in different shapes
• Linear and ring forms
Draw the ring structures of glucose
and ribose pg 14 sg
• Ribose ( 5 carbons)
• Glucose (6 carbons)
• Most names for sugars end in “ose”
• In aqueous solutions, glucose molecules
as well as most other sugars, form rings.
Disaccharide
• Consists of two monosaccharides joined
together by a glycosidic linkage, a
covalent bond formed during dehydration
reactions Dehydration SynthesisHydrolysis (go to carbohydrate synthesis)
Common Disaccharides (name two
disaccharides) pg 15 sg
Storage Polysaccharides
• Starch is a common PolySac of plants.
Consisting of glucose molecules
Glycogen another storage molecule
• Stored mainly in liver and muscle,
hydrolysis of glycogen releases glucose
Storage of starch in plants
• Plants store starch as granules within
cellular structures called plastids inside the
chloroplasts
Another structural poly sac is
cellulose sg 15
• Found in plant cell walls- structural support
• Due to the distinctive structures of starch
and cellulose, cellulose is indigestible to
humans .
• While cellulose is not a nutrient for
humans it remains as an important fiber.
Yet another structural poly sac
• Chitin: used by arthropods (insects,
spiders, crustaceans to form exoskeleton,
also found in cell wall of fungi)
• Tutorial 3.2 Macromolecules ( ann go to
animations, then cho )
Lipids- Diverse hydrophobic
molecules pg 15 sg
• Fat molecules are
made up of four parts:
• a molecule of
glycerol (on the right)
and
• three molecules of
fatty acids.
Structure of Fatty Acid
• Has a long carbon
chain, at one end is a
carboxyl group.
Attached to this is a
long hydrocarbon tail.
The non polar C-H
bond in the tails make
them hydrophobic
The glycerol and fatty acid join
• One molecule of
water is removed for
each fatty acid joined
to the glycerol.
• This results in a ester
linkage.
Saturated Fatty Acid
• Contain the maximum
possible amount of
hydrogens, thus
saturated fats. The
hydrocarbon chains in
these fatty acids are,
fairly straight and can
pack closely together,
making these fats
solid at room
temperature.
Unsaturated Fatty Acid
• some of the carbons
share double bonds,
they’re not bonded to
as many hydrogens
as they could if they
weren’t double.
Therefore these oils
are called
unsaturated fats.
They remain liquid
Look at the difference
Function of fats pag 15 sg
– energy storage molecules Fats possess more energy
per molecule and less hydration compared with
carbohydrates, resulting in fats possessing much
more energy stored per unit mass or volume fats
have 9cal/gram CHO and proteins have 4 cal/gram
– Stored as fats in animals and oils in plants
– In animals such as ourselves, fats are stored in
adipose cells
– Buoyancy – lipids are less dense than water allowing
animals to float
Phospholipids
• Major component of cell membranes
• Structure: Phospholipids are made from glycerol, two
fatty acids, and (in place of the third fatty acid) a
phosphate group
• The hydrocarbon tails of the fatty acids are hydrophobic
• the phosphate group end of the molecule is hydrophilic
because of the oxygens with all of their pairs of unshared
electrons.
• This means that phospholipids are soluble in both water
and oil.
•
• Phospholipids have
the special property of
having both
hydrophobic and
hydrophilic parts
• A molecule that is
both hydrophilic and
hydrophobic is called
amphipathic.
Structure of phospholipids
Function of Phospholipids
• Found in cell membranes. Act as barrier .
• When phospholipids are added to water
they self assemble, with hydrophobic parts
inward and hydrophilic parts outward.
• http://telstar.ote.cmu.edu/Hughes/tutorial/c
ellmembranes/orient2.swf
Another group of lipids are Steroids
• A lipid characterized
by a carbon skeleton
consisting of four
fused rings. One
common steroid is
cholesterol.
• Many hormones are
steroids, including sex
hormones
• Tutorial 3.2 Macromolecules ( ann go to
animations then to lipids)
Proteins
– Proteins are a major constituent of most cells
(>50% dry weight)
– All proteins consist of polymers that are folded
into specific conformations
– This conformation plus the chemistry of wellplaced functional groups control a protein's
function (another example of function follows
form)
– Proteins are made up of 20 different types of
amino-acid monomers
Polymers of amino acids are called
peptides pg 14 sg
• Remember the
structure of an amino
acid. Carboxyl and
amino group. A
protein consists of
polymers of amino
acids, folded and
coiled into a specific
configuration.
• The side group
determines
characteristics,
making it hydrophobic
or hydrophilic, acidic
or basic.
Coming together to make a peptide
bond.
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amino acid basics
Animation of Peptide Bond Formation
Animation - Amino acid condensation
The carboxyl group of one is adjacent to
the amino group of the other, an enzyme
can join the amino acids by dehydration
reaction.
Several function of proteins.
Pg 68 sg
• Structural proteins
act as support.
Examples include the
silk fibers of spiders
and insects, collagen
in animal connective
tissue, and keratin
found in hair, horns,
feathers.
Storage proteins
• Storage of amino
acids. Examples are
egg whites, casein,
found in milk, and
plants have storage
proteins in their
seeds.
Transport proteins
• Transport of other
substances,
Hemoglobin is an
example, transporting
oxygen from the lungs
to other parts of the
body. McGraw-Hill
Online Learning
Center Test<BLURT>
Hormonal Proteins
• They perform by
coordinating of an
organism's activities.
An example is insulin.
Movement Proteins
• Used for movement.
Examples are actin
and myosin found in
muscle tissue.
Defensive Proteins
• Protection from
disease. Antibodies
are an exampe.
Enzymatic Proteins
• Selective acceleration
of chemical reactions.
We will be discussing
enzymes in detail
later.
A proteins function depends on its
conformation.
• A polypeptide is not the same as a protein.
• The chain of amino acids known as a
polypeptide must be twisted and folded.
• Most proteins are globular (roughly
spherical) others are fibrous in shape.
Shape is everything
• In order for a protein to function properly it
must be able to be recognized and fit
properly to another molecule. (This is
important to remember when we speak of
enzymes)
Polar and non polar amino acids
(aa) pg 68 sg
• Polar aa have
hydrophilic R groups
• Found on surface of
proteins make them
water soluble
• Make channels for
hydrophilic
substances
• Positive charged R
groups allow – ions
through
• Positive charged R
groups allow – ions
through
• Integral or
transmembrane
proteins
• Transmembrane protein p 68sg
Non polar aa/pg 68
• In center of water
soluble proteins
stabilize structure
• Remain embedded
• Peripheral proteins
A proteins function depends on its
conformation. Pg 66 sg
• A polypeptide is not the same as a protein.
• The chain of amino acids known as a
polypeptide must be twisted and folded.
• Most proteins are globular (roughly
spherical) others are fibrous in shape.
2 types you need to know pg. 66sg
• Globular - clumped
•
into a shape of a ball.
Major examples
include insulin,
hemoglobin, and most
enzymes.
• http://student.ccbcmd.
edu/~gkaiser/biotutori
als/proteins/images/u
4fg1b3.jpg
• Fibrous proteins
Keratins - in wool,
hair skin, fur, claws,
nails, hooves, horns,
scales, beaks,
feathers, actin and
mysin in muscle
tissues and fibrinogen
needed for blood
clots.
• tropomycin
Four levels of protein structure all
driven by chemical bonds/67 sg
• Primary structure:
determined by base
structure of the gene
that codes fro the
polypeptide.
• A chain of amino
acids
Secondary Structure p 66+67
• Regular repeating structure including beta
sheets, and alpha helices stabilized by
hydrogen bonds between groups in the
main chain of the polypeptide.
Two types of secondary structure
• Alpha - Helix: the
first structure. It has a
rod shape. The
peptide is coiled
around an imaginary
cylinder and stabilized
by hydrogen bonds
formed between
components of the
peptide bonds
The second type
• Beta - pleated
sheets: the amino
acids adopt the
conformation of a
sheet of paper and
the structure is
stabilized by
hydrogen bonds
between amino
acids in different
polypeptide strands.
Lyzozyme
Tertiary structure pg 67
• The three dimensional conformation of a
polypeptide.
• Stabilized by intramolecular bonds that
form between aa in the
• Bonds form, ionic, hydrogen, hydrophobic
interactions and disulfide bridges.
Quaternary Structure
• Linking together of 2 or more polypeptides
to form a single protein
Hemoglobin pg 67
• Prosthetic groups – a non polypeptide
structure contained in a protein
• Heme group linked to each of the four
polypeptides in hemoglobin.
• Proteins with a prosthetic group are called
conjugated proteins
Protein folding
• Interactive Concepts in Biochemistry Interactive Animations
• http://www.stolaf.edu/people/giannini/flash
animat/proteins/protein structure.swf
• Proteins Structure Animation
• Tutorial 3.2 Macromolecules ( go to
proteins )
Nucleic acids are informational
proteins
• First type of nucleic
acid is
deoxyribonucleic acid
of DNA. The second
type is ribonucleic
acid or RNA.
• DNA is structurally
different than RNA.
• The sugar in DNA is
deoxyribose and in
RNA the sugar is
ribose
Nucleic acids are made of the
monomer called nucleotides
• Nucleotides are made
of three parts.
• 1. nitrogenous base
• 2. pentose ( a five
carbon sugar)
• 3. a phosphate group
Found in DNA and RNA
The Nitrogenous bases are 5 in
type
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1. Cytosine (C)
2. Thymine (T) found in DNA only
3. Uracil (U) found only in RNA
4. Adenine (A)
5. Guanine (G)
There are two families of
nitrogenous bases
• The pyrimidines:
• Has a six- membered
ring or carbon and
nitrogen .
• These include
cytosine, thymine,
and uricil
• And Purines:
• Larger, with the six
membered ring fused
to a five membered
ring.
• Includes: Adenine
and guanine
Found in DNA and RNA
Building a Polynucleotide
• Polynucleotides are
joined by covalent
bonds between the
phosphate sugar
Forms
phosphodiester bond
• This results in the
backbone of DNA and
RNA
Looks like this
DNA- you must be able to draw this
pg. 60 sg
• All along the
appendages are
attached the
nitrogenous bases
• Tutorial 3.2 Macromolecules ( go to
nucleic acids )
This all fits together
• The central dogma in
molecular biology is:
• DNARNAprotein
• You must be able to
draw DNA and RNA