Proteins Flashcards
What is a protein
Macromolecule made of amino acid monomers
Structure allows to carry out specific function in particular contex
What is an amino acid
Cominations of 3 nucleotides code for an amino acid
What is the structure of an amino acid
Amino acids are chiral because of R group, except glycine (R=H)
How are amino acids affect by pH
pH can give amino acid different charge
What are the different classification of amino acids
- Aliphatic
- Aromatic
- Sulfur-containing
- Basic
- Acidic
- Polar
(7. Miscellaneous)
Describe Aliphatic amino acids
R group consists of hydrocarbon chain
Descibre Aromatic amino acids
R group consists of hydrocarbon ring
Describe Sulfur-containing amino acids
R group has sulfur, can create disulfide bridges with other sulfur-containing amino acids
Describe basic amino acids
R group is basic
Describe acidic amino acids
R groups are acidic
Describe polar amino acids
R groups are polar
What is a miscellaneous amino acid
R group does not fit in any of the other classification
What different structures do proteins have
Primary, secondary, tertiary, quaternary
Describe primary structure
Chain of amino acid monomers into polypeptide, joined via peptide bonds
Describe secondary structure
3D arrangement of polypeptide chain
Hydrogen bonding between H of one amino acid and carboxyl oxygen of another in same chain
Can be alpha helix or beta pleated sheet
Describe tertiary structure
Functional R groups of amino acids within chain interact with on another
Van der Waals, ionic, hydrogen, disulphide and
hydrophobic interactions
Describe quaternary structure
Occurs when multiple polypeptides interact with one another, e.g. haemoglobin
What is denaturation
When protein chemical bonds are interrupted/destroyed and secondary and tertiary structure is lost
Rarely results in loss of primary structure
What functions do proteins have
THCRESSD
1. Structural
2. Enzymatic
3. Receptor
4. Hormonal
5. Transport
6. Storage
7. Defensive
8. Contractile
What proteins have quaternary structure
- Glycoproteins
- Lipoproteins
- Metalloproteins
What are glycoproteins
Prortieins with one or more carbs covalently attached
Co-translational or post-translational modification
What are the effects of Glycosylation
Gives proteins:
1. Stability
2. Solubility
3. Cell signalling
4. Orientation
What are lipoprotetins
Proteins that combine with lipids
Found in cell membranes and transport hydrophobic molecules
(e.g. cholesterol transport in the blood)
What are metalloproteins
Proteins with metal ions in their structures (co-factors)
Various functions (e.g. enzymatic, signal
transduction, storage and transport)
