Download VIII. PROTEINS, continued

Big Campbell ~ Ch 1-5
Baby Campbell ~ Ch 1-3
I. INTRODUCTION TO BIOLOGY
• Characteristics of Life
o Living things ……
o are made of __________
o grow & ______________
o _____________ to their
environment
o obtain and use ________
o maintain ____________
o are based on a universal
_____________ ______
o ________________
o ________________
I. INTRODUCTION TO BIOLOGY, CONTINUED
• Unity & Diversity of Life
o Evolution explains both unity & diversity
o Continuity of life based on DNA
o Two types of cells
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o All organisms can be placed in one of 3 domains
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o Form vs Function → Structures are adapted for specific
functions; conversely, function of a structure determines how
it is constructed
I. INTRODUCTION TO BIOLOGY, CONTINUED
• Unity & Diversity of Life, continued
o Levels of Organization (Big – Small)
 Biosphere
 Ecosystem
 Community
 Population
 Organism
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 Organelle
 Molecule
 Atom
II. CHEMICAL BASIS OF LIFE
• __________________
o Cannot be broken down without losing characteristic
properties
o Six elements in greatest concentration in living things are
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II. CHEMICAL BASIS OF LIFE, CONTINUED
• Atoms
o Smallest unit of
matter that retains
properties of that
element
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o Atomic Mass
II. CHEMICAL BASIS OF LIFE, CONTINUED
• Chemical Bonds
o Chemical behavior of atom determined by ______________ electrons
o Atoms interact with other atoms to complete their valence shells, either by
________________ or ________________ electrons
II. CHEMICAL BASIS OF LIFE, CONTINUED
• Types of Chemical Bonds
o ____________ – Results when one atom has a much
stronger attraction for electrons than another
o One atom has a greater __________________________. Electron(s)
are transferred resulting in formation of ions. Bond forms due to
charge attraction – easily broken
 Cation  Anion -
II. CHEMICAL BASIS OF LIFE, CONTINUED
o _________________ – Much
stronger that results from
___________ a pair of valence
electrons.
o Forms a molecule.
o One pair of electrons shared = single
covalent bond
o Two pair of electrons shared = double
covalent bond.
 ______________ covalent bond –
formed when electronegativity of
atoms is the same; H2
 ___________ covalent bond – formed
when one atom is more
electronegative; unequal sharing of
electrons results in slight charges at
either end of molecule http://users.skynet.be/eddy/ion_vs_covalent.swf
III. WATER
• Polarity of Water
III. WATER, continued
• Properties of Water
o ______________ “bonds”
o “Stickiness”
 _______________
 _______________
o Helps maintain a stable
temperature
 Has a high specific heat and a
high heat of vaporization
o Density of “solid” water ____
density of liquid water
 Important to environment;
insulates lakes, oceans
III. WATER, continued
o Solvent of Life (not universal…..but
versatile)
 _________________ – “Water-loving”;
polar molecules “pull apart” ionic
compounds & other polar molecules
 ________________ – “Water-hating”;
non-ionic and non-polar substances
are repelled by water
III. WATER, continued
• Dissociation of Water
o Rare, but measurable phenomenon
o (2)H2O → H3O+ + OH- → H+ + OHo pH = measurement of H+ conc
 -log10[H+]
 [H+] [OH-] = 1 x 10-14
o Acid – Substance that dissolves in water to increase H+; [H+] >
1 x 10-7; pH < 7
o Base - Substance that dissolves in water to decrease H+; [H+] <
1 x 10-7; pH > 7
o Water is a neutral substance; [H+] = [OH-]
o Buffers – Maintain a constant pH by donating, accepting H+
 Very important buffer system in blood to keep pH at 7.4
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IV. ORGANIC CHEMISTRY – THE STUDY OF
CARBON
• Atomic Structure of C
o 6 total electrons;
therefore has 4 valence
electrons
o Shares e- to fill valence
shell; can form up to 4
covalent bonds
o Hydrocarbon
o Isomer – Molecules with
same atomic make-up;
different arrangement of
atoms
IV. ORGANIC CHEMISTRY, continued
• Functional Groups
Hydroxyl – Polar due to greater electronegativity of oxygen.
Found in alcohols. “-ol”
Carbonyl
 Aldehyde – carbonyl group at end of C-skeleton
 Ketone – carbonyl group within C-skeleton
IV. ORGANIC CHEMISTRY, continued
Carboxyl – Acts an acid by donating H+
Amino – Acts as a base by picking up H+
IV. ORGANIC CHEMISTRY, continued
Sulfhydryl – Important in stabilizing protein structure
Phosphate – Typically an anion; gives its molecule a
negative charge
V. ORGANIC CHEMISTRY, continued
V. THE BIOMOLECULES
• Most are ____________ made up of single units
called ____________
• The different classes of macromolecules differ in the
nature of their monomers, but the chemical
mechanisms that cells use to make and break
polymers are basically the same.
V. BIOMOLECULES, continued
• _____________________________ (condensation)
• One monomer provides –H, the other provides –OH
• As a result……
• A water molecule forms
• 2 original monomers covalently bond together to
form polymer
• Requires input of energy, use of enzymes
V. BIOMOLECULES, continued
• ____________________ - “Break apart with water”
• Covalent bonds between monomers are broken when
hydrogen from a water molecule attaches to one
monomer and the hydroxyl group attaches to adjacent
monomer.
• Releases energy; reaction accelerated with enzymes
• Example - digestion
VI. CARBOHYDRATES
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Provide fuel, act as building material
Generally, formula is a multiple of ___________
Contain carbonyl group & multiple hydroxyl groups
Monomer = __________________________
VI. CARBOHYDRATES, continued
• Monosaccharides – usually found as ringed structures
o Pentoses
 Ribose
 Deoxyribose
○ Hexoses
 Glucose
 Fructose
 Galactose
VI. CARBOHYDRATES, continued
• _____________________
o 2 monosaccharides joined by a ________________
______________________, a covalent bond formed during
dehydration synthesis
o Example
 Sucrose – (glucose + fructose)
 Lactose – (glucose + galactose)
 Maltose – (glucose + glucose)
VI. CARBOHYDRATES, continued
• ________________________
o Many monosaccharides covalently bonded via glycosidic
linkages formed during dehydration synthesis
o Storage Polysaccharides
o Structural Polysaccharides
VI. CARBOHYDRATES, continued
• Storage polysaccharides
▪ __________________ – ___________ store glucose
as starch in cell structures called ______________. Starch has
helix shape due to bond angles. Humans have enzymes to
hydrolyze starch to glucose monomers.
▪ __________________ – Storage form of glucose in _________.
More highly-branched than starch. In humans, found mainly in liver, muscle
cells
VI. CARBOHYDRATES, continued
o Structural polysaccharides (structure is different than storage
polysaccharides)
 __________________ – polymer of glucose. Every other glucose is upside
down which forms parallel strands of glucose molecules held together
with H-bonds
 Cows/Termites
 _______________ – found in arthropod exoskeleton, cell walls of fungi
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VII. LIPIDS
Non-polar, ____________________ molecules
Hydrocarbons
Fats& Oils
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Glycerolo
Not true polymers but they are very large molecules
Macromolecules assembled through dehydration synthesis
Glycerol = 3-C alcohol
Fatty acids – long hydrocarbon chains ending with carboxyl
group
Triglyceride = glycerol + 3 fatty acids
Fatty Acid
Used for energy storage – contain > 2X energy as carbs
VII. LIPIDS, continued
 ____________________
 “Saturated with hydrogens”
 All _____________ bonds.
 Typically from animal source, _________ at room temp.
 Associated with greater health risk.
 ______________________
 Contain ____________ bonds, fewer H-atoms.
 Results in “kinked” hydrocarbon chain.
 Typically from _________ source, liquid at room
temp.
VII. LIPIDS, continued
• ___________________________
– Contain _______ fatty acids attached first 2-carboxyl groups of glycerol.
– Phosphate group is attached to 3rd carboxyl which has a negative charge.
– Therefore molecule is partially hydrophilic (_________) and partially
hydrophobic (_________) .
– Found in all cell membranes.
• Phospholipid bilayer
VII. LIPIDS, continued
• Waxes
– One fatty acid attached to an alcohol.
– Very hydrophobic.
– Used as coating, lubricant
• Steroids
– Consist of 4-rings with different functional groups attached.
– _____________________
• Found in animal cell membranes
• Precursor for sex hormones
VIII. PROTEINS
• Important for functions such as…… (Table 5.1, Pg. 72)
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Structural ______________ (very complex!)
Storage
_________________ of substances
Signaling
Movement
______________ disease
• ________________________ – Proteins are large polymers made
up of amino acid monomers.
• All amino acids have the same basic structure:
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Amino group
Carboxyl group
Carbon, known as ___________ carbon
_________________ → variable component; gives each amino acid its
unique properties. Determines whether amino acid is classified as polar,
non-polar, acidic, or basic.
VIII. PROTEINS, continued
These R-groups are non-polar……..therefore these amino acids are non-polar
VIIII. PROTEINS, continued
These R-groups are polar……..therefore these amino acids are polar
These R-groups either proton donors or proton acceptors……..therefore these
amino acids have acidic or basic properties
VIII. PROTEINS, continued
• Amino Acid → protein
o Dehydration synthesis results in formation of a ____________
bond
o _____________________ – many amino acids covalently
bonded together
o At one end there is a free ___________ group (N terminus) and at the
other end is a free ______________ group (C terminus)
VIII. PROTEINS, continued
• Amino acid sequence determines the protein’s ______
conformation
• Protein Conformation
o Protein’s __________ is related to its _________________.
o Generally, a protein must recognize/bind to another molecule to
carry out its function.
o _______________________ - A change in a protein’s shape.
Which results in a loss of protein’s ability to carry out
function.
o Four levels of protein structure
 Primary
 Secondary
 Tertiary
 Quaternary
VIII. PROTEINS, continued
 __________ –
Sequence of amino
acids
VIII. PROTEINS, continued
 ________________ –
Coiling of polypeptide
chain due to formation of
H-bonds between H of
amino end of one aa and
OH of carboxyl end of
another aa
 _________________ –
created from H-bonds
forming within one pp
chain
 __________________ – Hbonds form between aa in
parallel pp chains
VIII. PROTEINS, continued
 __________________ Involves interactions
between R groups of
amino acids. Helps to
give each protein its
unique shape.
 __________________
interactions – amino
acids with non-polar R
groups cluster together
at core of protein.
 _________________
bridges – important in
reinforcing shape of
protein; covalent bonds
that form between
sulfhydryl R groups of
amino acids, cysteine
VIII. PROTEINS, continued
 _______________ –
Proteins that are
formed from
interactions between 2
or more polypeptide
chains folded together.
 Examples:
 Hemoglobin, collagen,
chlorophyll
VIII. PROTEINS, continued
• __________________
o Biological catalysts that act by lowering _________________________;
that is, the amount of energy needed to get the reaction going
o Only catalyze reactions that would normally occur
o Recycled – not used up or changed by the reaction
o Temperature, pH, and salt sensitive
o Substrate specific
VIII. PROTEINS, continued
o ____________________ – As
enzyme envelops substrate, a
slight change takes place in bond
angles, orientation of atoms.
Allows chemical rxns to occur
more readily
o Inhibition of Enzyme Function
 __________________ inhibitor –
mimics normal substrate
 ____________________ inhibitor –
attaches to another part of enzyme;
changes shape of active site
VIII. PROTEINS, continued
o Regulation of enzyme
function
 ____________ regulation
– binding of a molecule
to enzyme that affects
function of protein at
another site
 __________________
______________ – as
end product is
synthesized and
accumulates, enzyme is
inactivated → switches
off metabolic pathway
VIII. NUCLEIC ACIDS
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Nucleic acid group includes DNA, RNA, ATP
Structure of Nucleic Acids
o Monomers = nucleotides
o Nucleotides composed of
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Pentose – deoxyribose or ribose
Phosphate group
Nitrogen base
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Pyrimidine – Contains 6-membered ring of C, N atoms
a) Cytosine – found in DNA, RNA
b) Thymine – found in DNA
c) Uracil – found in RNA
Purine – Larger; consists of 6-membered ring + 5-membered ring
a) Adenine – found in DNA, RNA, ATP
b) Guanine – found in DNA, RNA
VIII. NUCLEIC ACIDS, continued
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Nucleotide polymers – Formed through dehydration synthesis. Phosphate group
of one nucleotide covalently binds to sugar of next. Forms backbone of
alternating P-group and sugar.
o DNA – Forms double helix. Two polynucleotide strands run in opposite directions –
referred to as antiparallel. H-bonds form between N-bases in the center
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