Proteins Flashcards
What are the groups in an amino acid?
Amino group (NH2), carboxylic acid group (COOH), R group.
How many different groups does an amino acid group have?
3
What group in an amino acid changes?
The R group is a different molecule in different amino acids. Can make them neutral, acidic, alkaline, aromatic (has a ring structure) or sulphur-containing.
What happens in a condensation reaction between 2 amino acids?
The amino group from one amino acid and the acid group from the other form a bond, producing one molecule of water. The bond is called a peptide bond.
What is the primary structure of proteins?
The order and number of amino acids.
What is the secondary structure of proteins?
An alpha-helix or a beta-pleated sheet. Composed of H bonds. Overall stable (alpha is also elastic).
What is the tertiary structure of proteins?
The overall 3D structure of the protein.
What are the two types of tertiary structure proteins?
Fibrous and globular.
What is a globular protein?
Made of chains folded into a compact structure. E.g, enzymes.
Give an example of a globular protein based mostly on an alpha-helix
Haemoglobin
Give an example of a globular protein based mostly on an beta-pleated sheet
The immunoglobulin antibody molecule.
What is the quaternary structure of proteins?
A protein made up of several polypeptide chains.
What are the bonds involved in a tertiary structure protein?
Held together by H bonds between some of the R groups and ionic bonds between + and - charged side chains. Strong, covalent bonds called disulphide bridges between amino acids with sulphur on their side chains.
