Proteins Flashcards
What are proteins made up of?
Amino acid chains made of C, H, O, N mainly.
What are functions of proteins?
Structure, metabolic roles, transport
How many naturally occurring amino acids are there?
20
How are peptide bonds formed?
2 amino acids join by a condensation reactions to form a dipeptide
How is a polypeptide formed?
A series of condensation reactions joining many amino acids
What is the primary structure?
Specific sequence of amino acids in a polypeptide chain.
What is the secondary structure?
Curling/folding of the polypeptide chain into alpha helices or beta pleated sheets as H bonds form
What is the tertiary structure?
Overall 3D shape of a protein, determined by interactions between R groups and their properties
What types of bonds form between R groups?
Hydrogen, ionic, disulphide bridges.
What is the quaternary structure?
Specific 3D shape of a protein determined by the multiple polypeptide chains/prosthetic groups.
How do hydrophilic and hydrophobic R groups work?
Hydrophobic amino acids are found in the middle of the protein, and hydrophilic R groups are found on the outside.
What is a globular protein?
A protein with a spherical shape. Soluble in water, normally have metabolic roles.
What are examples of globular proteins?
Haemoglobin, insulin and pepsin.
What is the structure of haemoglobin?
4 polypeptide chains with an iron ion on each so it is a conjugated protein. The haem groups bind to O2
What is the structure of insulin?
2 polypeptide chains folded and joined by disulphide bonds. Specifically binds to receptors to lower blood glucose.
