Protein Structure
Terminology relating to proteins, globular V fibrous proteins, membrane proteins, hierarchical structures, bonds involved in hierarchical structures, structure V function relationship, interesting proteins, amino acid structure, peptide bond formation, properties of amino acids, importance of R-groups, mixture polymers
Terminology relating to proteins, globular V fibrous proteins, membrane proteins, hierarchical structures, bonds involved in hierarchical structures, structure V function relationship, interesting proteins, amino acid structure, peptide bond formation, properties of amino acids, importance of R-groups, mixture polymers
Set of flashcards Details
| Flashcards | 28 |
|---|---|
| Language | English |
| Category | Biology |
| Level | University |
| Created / Updated | 04.01.2020 / 07.09.2021 |
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Protein composition (CHNOS)
Carbon, Hydrogen, Nitrogen, Oxygen, Sulfur
Amino Acid (one, hundreds)
One amino acid is a monomer, proteins are made of hundreds of amino acid units
Di-,t ri-, tetrapeptide
Di = 2 amino acids
Tri = 3 amino acids
Tetra = 4 amino acids
Oligopeptide
Peptide chain with up to 25 amino acid units
Polypeptide
Chain with more than 25 amino acid units
Protein definition
Native structure of a folded polypeptide
Denaturation definition
Process where protein looses the quaternary, tertiary and secondary structure
Zwitterion definition
amino acids in solution become dipolar ions -> NH3+ & COO- (both negatively and positively charged
Amphoteric
Proteins can either be acidic or basic, depending on the condition of the solution they are in
Primary structue (structure, function)
Sequence of polypeptide chain (connected with peptide bonds) & contains a amino end (N-terminus) and a carboxyl end (C-terminus).
Dictates the function of the protein indirectly, is unique for every protein.
Secondary structure (structure (2), difference (2) bonds (2))
Determined by the structure of the backbone or linear chain
Amino acids either coil into a alpha helix or form a beta pleated sheet
Bonding: Peptide bonds, hydrogen bonds
Alpha helix (2)
Right handed helix, which is stabilized via hydrogen bonds (secondary structure)
Beta pleated sheet (2)
Polypeptide chains fold back upon itself and forming anti-parallel chains.
Hydrogen bonds stabilize the structure
Tertiary structure (structure, bond types (5))
Combination of secondary structures, three dimensional arrangement
Bonding: Hydrogen, ionic, disulfide (very strong), hydrophobic interactions, van der waals
Quarternary structure (structure (2), bond (7))
Proteins with more than one polypeptide chain, each chain has an iron containing HAEM group which binds to oxygen.
Bonding: Hydrogen, ionic, disulfide (very strong), hydrophobic interactions, van der waals
Native conformation definition
The shape a protein naturally folds into, also the useful conformation in which it can do catalization.
Globular Protein (appeareance, function, example)
Spheric shape
Hydrophilic (soluble in water)
Hemoglobin (enzymes, some transport & hormones)
Fibrous Protein (appearance, function, example)
Strand-like shape
Hydrophobic (not soluble in water)
Example: Collagen
Membrane Protein (structure, solubility)
Contain globular regions
soluble in non-polar solvents and hydrophobic (insoluble in water) -> anchores them in lipid layer of the membrane
Bonds in structures (1,2,3,4,)
Primary: Peptide bonds
Secondary: " and hydrogen bonds
Tertiary: Hydrogen, ionic, hydrophobic interactions, disulphide bonds, van der waals
Quaternary: Hydrogen, ionic, hydrophobic interactions, disulphide bonds, van der waals
Bonding (Peptide, Hydrogen, Disulphide, Ionic, Hydrophobic, Van der Waals)
Peptide bonds: Water molecule is eliminated when NH2- (from aa 1) and COO- (from aa 2) react to build a bonds between two amino acids -> linear structure
Hydrogen bonds: Hydrogen binding to a highly electronegative atom (oxygen,nitrogen, fluorine) -> responsible for helical or beta pleated structure
Disulphide bonds: Occur between cysteine amino acids (cause of SH group) and form S-S bonds -> provides rigidity to structure
Ionic bond: Bond between oppositely charged amino acids
Hydrophobic bond: Bonds to create a hydrophobic core (exterior is hydrophilic)
Van der Waals forces: Adjacent weak interaction
Structure impacts function (globular (3), fibrous (2) , membrane (3))
Globular: Hydrophillic surface -> Act in aquaeous environment (cytoplasm), move around, interaction with other soluble molecules
Fibrous: Very stable -> suitable for main components in long-live structures (others stretch and recoil without tearing)
Membrane: Hydrophobic part on outside and hydropilic part on inside -> lipid soluble (embedded in membrane)
Myosin (structure linked to function)
Both globular and fibrous parts
Important for movement -> length have fibrous structure and globular enzyme
Actin (structure linked to function)
Important for movement -> Globular protein which forms a filamentous shape
Collagen (structure linked to function)
Quatenary but no tertiary structure
Structure of amino acid
Carbon with:
a amino group (NH2)
Caboxyl group (COOH)
Hydrogen
R- side chain
What is an L-amino acid?
Every amino acid (except from cystine) can form two steroisomers around central carbon atom (amino and carboxyl group switch sides)
L = left handed configuration (amino group is left)
Why is R-group important?
Determines size, pH, polarity, reactivity, hydrophobicity of amino acids
