2.1.2: Proteins Flashcards
What are proteins made up of?
Proteins are made up of one or more large polymers, creating a macromolecule.
Proteins consist of long chains of amino acids linked together by peptide bonds.
What is the general structure of an amino acid?
An amino acid consists of an amine group, a carboxyl group, a hydrogen atom, and a variable R group.
The R group differs in all 20 amino acids.
What determines the primary structure of a protein?
The primary structure is determined by the unique sequence of amino acids in a polypeptide chain.
This sequence is encoded by DNA.
How many levels of structural arrangements are there in a protein?
There are up to four levels of structural arrangements in a protein.
These levels are primary, secondary, tertiary, and quaternary structures.
What is a peptide bond?
A peptide bond is formed between amino acids during condensation reactions, linking them together in a polypeptide chain.
This bond results from the removal of a water molecule.
What characterizes the secondary structure of a protein?
The secondary structure is characterized by parts of a protein bending into an alpha helix or folding into a beta pleated sheet.
Hydrogen bonds stabilize the secondary structure.
What forces hold the tertiary structure of a protein together?
The tertiary structure is held together by:
* Hydrophobic and hydrophilic interactions
* Hydrogen bonds
* Ionic bonds
* Disulfide bonds
Disulfide bonds are strong covalent bonds that form between R-groups containing sulfur.
What is the role of hydrogen bonds in the secondary structure?
Hydrogen bonds between the carboxyl groups of one amino acid and the amine group of another hold the secondary structure in place.
These bonds are weak individually but provide strength collectively.
What is the quaternary structure of a protein?
The quaternary structure is the arrangement of multiple polypeptide chains in a protein.
This structure is formed when two or more polypeptide chains come together.
Fill in the blank: The sequence of amino acids causes parts of a protein molecule to bend into an _______ or fold into a _______.
alpha helix; beta pleated sheet.
These formations are integral to the protein’s secondary structure.
