Topic 2.4: Proteins Flashcards
Monomer of a protein
Amino acids
Structure of amino acids
a) Amine (NH2)
b) Carboxyl (COOH)
c) Hygrogen atom
d) R group
Polypeptide
Long chains of amino acids
How are polypeptides formed and broken down?
a) Joined together by condensation reactions
b) Broken down by hydrolysis reactions
Peptide bond
Covalent bond between amino acids
Primary structure of proteins
a) Order and number of amino acid sequence
b) Formed by covalent peptide bonds
Secondary structure of proteins
a) Folding into repeat patterns
b) By hydrogen bonds between amine and carboxyl groups.
Common secondary structures of proteins
a) Alpha-helix
b) Beta-pleated sheets
Tertiary structure of proteins
a) Overall 3D arrangement of a polypeptide
b) Determined by interactions between variable side chains.
Quaternary structure of proteins
Association of multiple polypeptides and prosthetic groups
Example of a protein with quaternary structure
Hemoglobin
a) Two alpha-helix
b) Two beta.pleated sheets
c) Haeme groups
Denaturation
Structural change in a protein that results in the loss of its biological properties.
Denaturation factors
a) Temperature
b) pH
Denaturation due to temperature
a) Hydrogen bonds are disrupted at high temperatures.
b) Protein unfolds and loses its capacity to function.
Denaturation due to pH
a) Changing the pH will disrupt ionic bonds, alter protein solubility, and overall shape
b) Optimal protein
