Protein Flashcards
What is the structure of a protein
The alpha-carbon in centre Amino group ( N + 2H’s) R side chain Hydrogen Carboxylic acid group (=O and OH)
What do proteins contain, which elements
Carbon, Hydrogen, Oxygen and Nitrogen sometimes Sulphur CHONs
What happens when an Amino Acid is ionised?
The H from the carboxylic acid group moves to the amino group
What reaction joins two AA’s?
A condensation reaction forms a peptide bond
What is the name of two Amino Acids joined by a peptide bond?
A dipeptide
What is the name of more than two Amino acids joined by peptide bonds?
A polypeptide
Where do peptide bonds form on an Amino acid?
One amino group of one AA and the carboxylic acid group of another.
What is the primary structure of a protein
The number, type and sequence of amino acids that make up the polypeptide chain
What are the two forms of secondary structure
Alpha-helix Beta-Pleated Sheet
What structure is formed in protein folding? (Tertiary structure)
Globular proteins
What are the three types of bond holding a protein in its tertiary structure?
Sulfide Crosslinks Salt bridges Hydrogen Bonding
What is a quaternary structure?
When the protein consists of more than one polypeptide chain
Characteristics of Fibrous Proteins
Little or no tertiary structure Insoluble in water Long parallel polypeptide chains Very tough Eg, collagen, keratin or silk
Characteristics of Globular Proteins
Complex tertiary + sometimes quaternary structure Globular shapes Soluble in water
What are conjugated proteins?
Protein molecules that are joined with another molecule called a prosthetic group
