Download Protein

Doris Lee
Even Zheng
Joanna Tang
Kiki Jang
Rachel Zhang
Vincent Ma
 Proteins, one
of the most important
biological molecules in our body. They
are included in virtually all of the cell
functions.
 Antibodies-
are
proteins that are
specialized to defend
our body from antigens
 Contractile Proteinsare responsible for
movement.
 Enzymes-
are catalysts that speed up the
biological reactions.
 Hormonal Proteins- are messenger
proteins which help to coordinate certain
bodily activities.
 Structural Proteins- are fibers that
provide support.
 Storage
Proteins- are
used to store amino
acids.
 Transport Proteinsare carrier proteins
that circulate other
molecule around the
body.
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proteins are made up of amino acids
amino acids link together to form
polymers = proteins
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Amino acids are made up of an amino group
(-NH2) and a carboxylic acid group (COOH), distinguished by the attached
functional group R.
The key elements of amino acids are
Carbon, Hydrogen, Oxygen and Nitrogen.
The most common amino acid is shown
above, with a carbon atom attached to the
carboxyl group, called an alpha amino acid.
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Amino acids have properties of both acids
and bases. The amino group gives the
amino acids its basic properties and the
carboxyl group gives amino acids its acidic
properties.
R represents a group called a side chain
which varies from one amino acid to
another. It distinguishes an amino acid as a
weak acid or a weak base, and a hydrophile
if the side-chain is polar or a hydrophobe if
it is non-polar.
Peptide bond is a covalent bond that joins 2 amino acid
Ex. A polypeptide is a string of amino acids joined by peptide bonds
A dipeptide results when 2 amino acids join and also forms water as a by
product
dipeptide formation
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http://www.mrothery.co.uk/images/Image46.gif
The differences between
primary, secondary, tertiary,
and quaternary structure
 Composed
of amino acids →polypeptide chains
a
slight change in the structure can effect the
appearance and function of the protein
 ex. Blood
cell →sickled cell
 is
made up of repeated
coils and folds of
polypeptide chains
 result of hydrogen
bonds at regular
intervals along
polypeptide backbone
 two types: helix
pleated sheet
 superimposed
on the patterns of
secondary structures
 contortion caused by the interaction in
side chains of amino acids
2
types of interactions
 hydrophobic: clustering of hydrophobic
group away from water
 Van de Waals: weak bonds between side
chains that hold the protein in a specific
conformation
 the appearance of the structure can be
reinforced by a covalent bond called
disulfide bridges
 result
from the aggregation of
polypeptide subunits
 made up of primary, secondary, and
tertiary structures
 Primary
Structure is a sequence of amino
acids (line)
 Secondary Structure is pleated sheet or
helix (flat and 2D)
 Tertiary
structure is
3D
 Quaternary is more
complicated,
combined with
different protein
structures
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1187960561_jpg.html
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http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/
PrimaryStructure.html
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http://www.cs.nott.ac.uk/~nxk/TEACHING/G6DHLL/COURS
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a.htm