Submitted by: Arambulo, Ruth Alexis Caballes, Kristine

8/14/2019 Submitted by: Arambulo, Ruth Alexis Caballes, Kristine

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PROTEIN

SUBMITTEDBY:

ARAMBULO, RUTH ALEXIS

CABALLES, KRISTINE KIMCATUBAY, ROBBI MILLI

LOSANES, MARIEL ANGELICA

MORALES, FRANCESCARAPOSAS, JESY ELISSE


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Resonance Structures Of the bond thatlinks individual amino acids to form aprotein polymer.

Proteins are linear polymers built from20 different L--amino acids. All aminoacids possess common structuralfeatures, including a carbon to which anamino group, a carboxyl group, and avariable side chain are bonded. Only

proline differs from this basic structureas it contains an unusual ring to the N-end amine group, which forces the CONH amide moiety into a fixed

conformation. The side chains of thestandard amino acids, detailed in the list

of standard amino acids have differentchemical properties that produce three-dimensional protein structure anddifferent reactivities, are thereforecritical to protein function.
http://en.wikipedia.org/wiki/File:Peptide_group_resonance.png


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Section of a protein structureshowing serine and alanineresidues linked together bypeptide bonds. Carbons are shown

in white and hydrogen are omittedfor clarity. The amino acids in apolypeptide chain are linked bypeptide bonds. Once linked in theprotein chain, an individual aminoacid is called a residue, and the

linked series of carbon, nitrogen,and oxygen atoms are known asthe main chain or proteinbackbone.

The peptide bond has two resonance forms that contribute

some double-bond character and inhibit rotation around itsaxis, so that the alpha carbons are roughly coplanar. The other

two dihedral angles in the peptide bond determine the localshape assumed by the protein backbone.
http://en.wikipedia.org/wiki/File:Peptide_bond.jpg


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POLYPEPTIDE CHAIN AND PEPTIDE BOND

The amino acids in a polypeptide chain are linked bypeptide bonds. Peptide is generally reserved for ashort amino acid oligomers often lacking a stable

three-dimensional structure. Polypeptide can refer toany single linear chain of amino acids, usuallyregardless of length, but often implies an absence ofa conformation.


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PROTEIN STRUCTURE

Three possible representations of the three-dimensional structureof the protein triose phosphate isomerase.

Left: all-atom representation colored by atom type.Middle: simplified representation illustrating the backbone

conformation, colored by secondary structure.

Right: Solvent-accessible surface representation colored byresidue type (acidic residues red, basic residues blue, polarresidues green, nonpolar residues white).
http://en.wikipedia.org/wiki/File:Proteinviews-1tim.png


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Molecular surface of several proteins showing theircomparative sizes. From left to right are:

immunoglobulin G (IgG, an antibody), hemoglobin,insulin (a hormone), adenylate kinase (an enzyme),and glutamine synthetase (an enzyme).


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PRIMARY, SECONDARY, TERTIARY ANDQUARTERY STRUCTURES


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PRIMARY STRUCTURE

Primary proteinstructure is asequence of a chain ofamino acids.

Exact specification ofits atomic compositionand the chemical

bonds connectingthose atoms(includingstereochemistry).


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SECONDARY STRUCTURE

A representation of the 3D

structure of the myoglobinprotein. Alpha Helices are

shown in colour, and randomcoil in white, there are no beta

sheets shown.

This protein was the first to

have its structure resolved byx-ray crystallography.

The general three-dimensionalform of local segments of

biopolymers such as proteinsand nucleic acids (DNA/RNA).


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TERTIARY STRUCTURE

One complete proteinchain of hemoglobin.

It is considered to belargely determined bythe protein's primarystructure, or thesequence of aminoacids of which it iscomposed.


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QUARTERY STRUCTURE

The four separatechains of hemoglobinassembled into an

oligomeric protein.

The arrangement ofmultiple folded protein

molecules in a multi-subunit complex.


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Cellular Functions of Protein

A.Enzymes

The best-known role ofproteins in the cell is asenzymes, which catalyze

chemical reactions.Enzymes are usually highlyspecific and accelerate onlyone or a few chemicalreactions. Enzymes carryout most of the reactions

involved in metabolism, aswell as manipulating DNA inprocesses such as DNAreplication, DNA repair, andtranscription.


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B. Cell Signaling and Ligand Binding

Many proteins are involved in theprocess of cell signaling and signaltransduction. Some proteins, such asinsulin, are extracellular proteins thattransmit a signal from the cell in whichthey were synthesized to other cells in

distant tissues. Others are membraneproteins that act as receptors whosemain function is to bind a signalingmolecule and induce a biochemicalresponse in the cell. Many receptorshave a binding site exposed on the cell

surface and an effector domain withinthe cell, which may have enzymaticactivity or may undergo aconformational change detected byother proteins within the cell.

A mouse antibody against

cholera that binds a

carbohydrate antigen.
http://en.wikipedia.org/wiki/File:Mouse-cholera-antibody-1f4x.png


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C. Structural Proteins

Structural proteins confer stiffness and rigidity tootherwise-fluid biological components. Most structural

proteins are fibrous proteins; for example, actin and

tubulin are globular and soluble as monomers, butpolymerize to form long, stiff fibers that comprise the

cytoskeleton, which allows the cell to maintain its shapeand size. Collagen and elastin are critical components of

connective tissue such as cartilage, and keratin is foundin hard or filamentous structures such as hair, nails,

feathers, hooves, and some animal shells.


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BYE.

Submitted by: Arambulo, Ruth Alexis Caballes, Kristine

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