BIOMOLECULES

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Transcript BIOMOLECULES

INTRO TO CHEMISTRY
COOMES
PRE-AP BIOLOGY
WHAT ARE ELEMENTS?
Cannot be broken down
 92 naturally occurring
 25 required by living organisms
 CHON
(Carbon,Hydrogen,Oxygen,Nitrogen)
make up 96.3% of human body
 Atom: smallest unit of an element

COMPOUNDS
Composed of 2 or more elements
 Examples: Sodium Chloride, Water,
Carbon Dioxide
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SUBATOMIC PARTICLES

Atoms are made of 3 types of
particles:
• Protons: positive charge, in nucleus
• Neutrons: neutral charge, in nucleus
• Electrons: negative charge, outside of
nucleus in electron cloud (orbitals)
PERIODIC TABLE
Contains all of the elements,
arranged by class (metals, nonmetals, noble gases, rare earths)
and atomic number
 Atomic number: Number of protons
 Isotope: Elements with same atomic
number but different atomic mass
(different number of neutrons)
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IONIC BOND
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Ion: charged atom
that has lost or
gained electrons
Ionic bond: eletron
is transferrred
Example: Sodium
chloride (table salt
Table Salt
Ionic bond
Crystal lattice
structure: very
stable & strong
COVALENT BONDS
Electrons are shared between atoms
 Single bond: C-C
 Double bond: C=C
 Triple bond:C=C
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COVALENT BONDS
When eletrons are
unequally shared, the
molecule is POLAR
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Polar molecules are
charged molecules
Hydrophilic
When electrons are
shared equally, the
molecule is
NONPOLAR
 Nonpolar molecules
are neutral
 Hydrophobic
HYDROGEN BONDING
• Contribute to unique properties of water
• Relatively weak bonds
COHESION

Linking of like molecules
• Water Strider (Surface Tension)
• Adhesion

Water on windshield
• Transpiration
Water moves up the xylem (thin tubes) and
evaporates from stomata
 Cling together by cohesion, “adhere” to
xylem walls
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HIGH SPECIFIC HEAT
Amount of heat required to raise or
lower temperature by 1̊ C
 Moderation of temperature

• Makes ocean temp relatively stable and able to
support more animal & plant life
INSULATION OF WATER BY
FLOATING ICE

Water is less dense as a solid
UNIVERSAL SOLVENT

Able to dissolve both acids & bases
PROPERTIES OF WATER LAB
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Cohesion
• Adhesion
• Surface Tension
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Hydrophobic/Hydrophilic Interactions
• Polar vs. Nonpolar
pH Scale
Acids: excess Hydrogen Ions (H+)
 Bases: excess Hydroxide OH
 Buffers minimize change in pH
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• Accept excess Hydrogen ions or donate
depleted Hydrogen ions
• Ex: Carbonic Acid (H2CO3): buffer in
living systems
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Blood plasma, ocean
pH Lab
What did we do?
 Control?
 Hypotheses?
 How would you determine pH
without the color card?
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BIOMOLECULES
PRE-AP BIOLOGY
BIOCHEMISTRY

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Chemistry of living
things organized
around CARBON
(organic
chemistry)
Methane: simplest
carbon compound
• Major component of
natural gas
HYDROCARBONS
Molecules made of only hydrogen
&carbon
 2 ways to represent structures:
 Model

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Formula
COVALENT BONDS
Share electrons
 Single, double, triple bond
 Hydrogen: 1
 Oxygen: 2
 Nitrogen: 3
 Carbon: 4
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FUNCTIONAL GROUPS
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1.
2.
3.
R=hydrocarbon group
Alcohol
Carboxyl
Amines
ALCOHOL
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Functional group:
(R-OH)
Hydroxide: base
R-OH: makes
alcohols more
soluble in water
than similar
molecules
Methanol: wood
alcohol (antiseptic)
Ethanol: beverage
Methanol
Ethanol
CARBOXYL
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R-COOH (acid)
Releases hydrogen
ions in water
“Organic acids”
AMINES
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R-NH2
Organic bases
because they
accept hydrogen
ions from acids
CARBOHYDRATES
Provide energy for cells when broken
down
 Organic compounds made of Carbon,
Hydrogen, & Oxygen
 Most have 2 atoms of hydrogen for
every oxygen
 Classified by # sugar units
 Example: pasta
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MONOSACCHARIDES
Carbohydrate made of one sugar unit
 Most common simple sugar: glucose
 Primary cellular fuel of most
organisms
 The building blocks of larger CHO
 Combined through biosynthesis
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GLUCOSE
GALACTOSE
FRUCTOSE (fruit sugar)
2 Monosaccharides=1
Disaccharide
Sucrose (table sugar): glucose + fructose
Malt Sugar=Glucose + Glucose
Milk Sugar=Glucose + Galactose
POLYSACCHARIDE
>2 monosaccharides
 Broken down through hydrolysis
 Cellulose
 Starch
 Glycogen
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CELLULOSE
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Major part of leafy vegetables, whole wheat, carrots, &
other plant material in your diet
Often called ‘fiber’ or ‘roughage’
Body cannot break it down into any glucose molecules
No energy received from fiber
More fiber seems to decrease the risk of cancer in the
digestive tract
Only digested by microorganisms & a few wood-eating
beetles
Animals that eat grass & leaves depend on these
microorganisms in their digestive tracts to digest cellulose
for them
Important to diet
STARCH
100’s-1000’s of glucose molecules
 Examples: potatoes, pasta
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GLYCOGEN
Like starch but for animals
 Animals store energy as glycogen
 Stored in liver & muscles
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LIPIDS
Non-polar organic molecules
 Do not dissolve in water
 Examples: vegetable oil, butter,
furniture wax
 Functions:

• Barrier b/t cell & environment
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Ex: lipid bilayer, blubber in whales
• Store energy

Fatty acids: building blocks of lipids
SATURATED FAT
Maximum # hydrogen atoms
attached to it (SOLID)
 Non-polar
 Insoluble in water
 No C=C bonds
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UNSATURATED FAT
Molecules with double bonds
 C=C
 LIQUID
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POLYUNSATURATED: >2 C=C
TRIGLYCERIDES
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Majority of fat in an organism
Composed of 3 fatty acids & a 3-C alcohol
(glycerol)
Examples:
• Butter & Lard
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Made from saturated fatty acids
Solid at room temp (fat)
• Corn oil & peanut oil
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Made from unsaturated fatty acids
Liquid at room temp (oil)
More common in plants than animals
FACTS
Body can store 3-month supply of
triglycerides & less than a day’s
supply of CHO
 Saturated fat=linked to heart disease
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AMINO ACIDS
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ALL organisms are composed of
combinations of the same 20 amino acids
Amino acid are joined by peptide bonds
Building blocks of proteins
4 parts
•
•
•
•
Hydrogen
Amino group
Carboxyl
R-group (hydrocarbon that determines identity
of amino acid)
20 AMINO ACIDS
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Alanine
Lysine
Asparagine
Proline
Threonine
Glycine
Valine
Isoleucine
Arginine
Phenylalanine
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Serine
Glutamic acid
Tyrosine
Histidine
Leucine
Methionine
Aspartic acid
Cysteine
Tryptophan
Glutamine
STRUCTURE OF AN AMINO
ACID
PROTEINS
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Amino acids are the building blocks of
proteins
Variety of structure & function
MAIN FUNCTION: source of raw materials
• Supplying cells with materials to make new
body parts
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Animals are primary sources in diet
• Meat, fish, dairy
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Plant: soybeans, beans, legumes
Examples: hair, feathers, spider webs
MAKING LARGE MOLECULES
FROM SMALLER ONES
Monomer: fundamental molecular
unit
 Polymers & macromolecules result
when the same type of units are
linked
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TYPES OF REACTIONS
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Dehydration
• Most common way to synthesize organic
polymers
• Loss of water=reaction between
monomers=formation of polymers
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Hydrolysis
• Breaking apart with water
• Most common way polymers are
degraded
ANABOLIC STEROIDS

Synthetic & natural variations of
testoterone
• Testoterone: increases bone mass & muscle
during puberty (in males)
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Used to treat anemia & diseases that
destroy muscle tissue
If abused, these drugs can cause
depression & mood swings
Can cause liver damage, high blood
pressure & high cholesterol levels
ANABOLIC STEROIDS (cont.)
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Use of steroids can cause the body to
decrease its production of
testoterone, causing:
• Shrunken testicles, infertility, reduced
sex drive, & breast enlargement in
males
• Use by women: menstrual cycle
disruption, development of masculine
characteristics
• Use by teens: bones may stop growing
THG (Tetrahydrogestrinone)
Modified to avoid detection in
ordinary drug testing
 Declared illegal by FDA, first penalty
given in 2004 to British sprinter
 Blood doping???
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PROTEIN SHAPE
Determines function
 Denaturation (caused by change in
salinity/temp/ionic charge) can cause
loss of functionality
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PROTEIN STRUCTURE
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Primary: determined by genetic
inheritance
• Amino acid sequence
• Single amino acid change: sickle cell
anemia
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Secondary: alpha helix or betapleated sheet
• Pleated sheet: hydrogen bonds work
together to make protein strong (spider
web)
PROTEIN STRUCTURE
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Tertiary:globular or fibrous
• Interacting R-groups
• Hydrophobic groups: clump/cluster

Quaternary: 2 or more polypeptide
chains (subunits)
• Subunit interactions associated with
quaternary structure
TRANSTHYRETIN
Transports vitamin A & thyroid
hormone in blood
 127 amino acids (primary)
 One alpha helix, many pleated
sheets (secondary)
 Globular (tertiary)
 4 identical globular subunits
(quaternary)
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LINUS PAULING
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Begin work in chemistry (with chemical
bonding) won Nobel Prize
Known for his strong opinion against nuclear
weapons testing..won Nobel Peace Prize
Studied Vitamin C and its benefits (but
believed it could cure the cold and cancer
Hemoglobin’s relationship to sickle cell
anemia
Believed in beginning small & increasing
studies
Died in 1994