Proteins Flashcards
(28 cards)
What is an amino acid?
The monomer from which proteins are made up of.
How many amino acids are found in nature?
20
What is the bond between 2 amino acids called?
Peptide bond
Which part of the amino acids does the peptide bond form between?
The carbon in the carboxyl group of one amino acid and the nitrogen in the amino group of the other amino acid.
What is the primary structure of a protein?
The sequence of amino acids in the polypeptide chain.
What is the secondary structure of a protein?
The description of how the polypeptide chain folds.
It can either fold to form an alpha-helix or beta-pleated sheet.
What determines the secondary structure?
The order of amino acids in the polypeptide chain.
What is the tertiary structure of a protein?
The further folding of a polypeptide chain to form a 3D shape.
What is the tertiary structure determined by?
The R groups of the amino acids.
What additional bonds can be formed in a tertiary structure?
-Ionic bonds
-Hydrogen bonds
-Disulfide bridges
Where are the bonds in a tertiary structure formed?
Between the R groups of the amino acids in the polypeptide chain.
When are disulfide bridges formed?
When there are two amino acids in a tertiary structure with sulfur in their functional groups a disulfide bridge can be formed between them.
What is the quaternary structure of a protein?
When multiple plolypeptide chains join together.
What subunits can be found in a quaternary protein structure?
Polypeptide chains, possibly of different structures.
Non-protein groups associated with the molecules can also be found in quaternary proteins.
What is a fibrous protein?
Long chains which run parallel to one another.
The chains are linked by cross-bridges (bonds)
Give an examle of a fibrous protein.
Collagen.
What functions do fibrous proteins have?
Usually structural functions.
What is a globular protein?
Globular proteins have a spherical structure and are insoluble in water.
Give examples of a globular protein.
Haemoglobin.
Enzymes.
If a protein is only one polypeptide chain what will its final structure be?
Tertiary structure.
If a protein is more than one polypeptide chain what will its final structure be?
Quaternary structure.
What additional bonds are found in secondary protein structures?
Hydrogen bonds.
What bonds are found in primary protein structures?
Peptide bonds.
What type of bond is a disulfide bond?
Covalent bond.
